Do-it-yourself homemade LED flashlights. We make our own LED lights. Checking and uploading contacts

We make a flashlight on LEDs with our own hands

LED flashlight with 3V converter for LED 0.3-1.5V 0.3-1.5 VLEDflash light

Usually, a blue or white LED requires 3 - 3.5v to operate, this circuit allows you to power a blue or white LED with low voltage from a single AA battery.Normally, if you want to light up a blue or white LED you need to provide it with 3 - 3.5 V, like from a 3 V lithium coin cell.

Details:
Light-emitting diode
Ferrite ring (~10 mm diameter)
Winding wire (20 cm)
1kΩ resistor
N-P-N transistor
Battery




Parameters of the used transformer:
The winding going to the LED has ~45 turns wound with 0.25mm wire.
The winding going to the base of the transistor has ~30 turns of 0.1mm wire.
The base resistor in this case has a resistance of about 2K.
Instead of R1, it is desirable to put a tuning resistor, and achieve a current through the diode ~ 22mA, with a fresh battery, measure its resistance, then replacing it with a constant resistor of the received value.

The assembled circuit must work immediately.
There are only 2 reasons why the scheme will not work.
1. the ends of the winding are mixed up.
2. too few turns of the base winding.
Generation disappears, with the number of turns<15.



Put the pieces of wire together and wind around the ring.
Connect the two ends of different wires together.
The circuit can be placed inside a suitable enclosure.
The introduction of such a circuit into a flashlight operating from 3V significantly extends the duration of its operation from one set of batteries.

Variant of execution of a lamp from one battery 1,5v.





The transistor and resistance are placed inside the ferrite ring



White LED powered by a dead AAA battery


Modernization option "flashlight - pen"


The excitation of the blocking generator shown in the diagram is achieved by a transformer connection at T1. The voltage pulses that occur in the right (according to the scheme) winding are added to the voltage of the power source and fed to the VD1 LED. Of course, it would be possible to exclude the capacitor and resistor in the base circuit of the transistor, but then VT1 and VD1 may fail when using branded batteries with low internal resistance. The resistor sets the operating mode of the transistor, and the capacitor passes the RF component.

The circuit used a KT315 transistor (as the cheapest, but any other with a cutoff frequency of 200 MHz or more), an ultra-bright LED. For the manufacture of a transformer, a ferrite ring is required (approximate size 10x6x3 and a permeability of about 1000 HH). The wire diameter is about 0.2-0.3 mm. Two coils of 20 turns each are wound on the ring.
If there is no ring, then a cylinder similar in volume and material can be used. You just have to wind 60-100 turns for each of the coils.
Important point : you need to wind the coils in different directions.

Flashlight photos:
the switch is located in the "fountain pen" button, and the gray metal cylinder conducts current.










We make a cylinder according to the size of the battery.



It can be made from paper, or a piece of any rigid tube can be used.
We make holes along the edges of the cylinder, wrap it with tinned wire, pass the ends of the wire into the holes. We fix both ends, but leave a piece of conductor at one of the ends: so that you can connect the converter to the spiral.
A ferrite ring would not fit into a lantern, so a cylinder of similar material was used.



Cylinder from an inductor from an old TV.
The first coil is about 60 turns.
Then the second, winds in the opposite direction again 60 or so. The threads are held together with glue.

We assemble the converter:




Everything is located inside our case: We unsolder the transistor, the resistor capacitor, solder the spiral on the cylinder, and the coil. The current in the coil windings must go in different directions! That is, if you wound all the windings in one direction, then swap the conclusions of one of them, otherwise generation will not occur.

It turned out the following:


We insert everything inward, and use nuts as side plugs and contacts.
We solder the coil leads to one of the nuts, and the VT1 emitter to the other. Glue. we mark the conclusions: where we will have an output from the coils, we put “-”, where the output from the transistor with the coil we put “+” (so that everything is like in a battery).

Now you should make a "lamp diode".


Attention: on the base should be minus the LED.

Assembly:

As is clear from the figure, the converter is a "substitute" for the second battery. But unlike it, it has three points of contact: with the plus of the battery, with the plus of the LED, and the common body (through the spiral).

Its location in the battery compartment is specific: it must be in contact with the positive of the LED.


Modern flashlightwith the mode of operation of the LED powered by constant stabilized current.


The current stabilizer circuit works as follows:
When power is applied to the circuit, transistors T1 and T2 are locked, T3 is open, because an unlocking voltage is applied to its gate through resistor R3. Due to the presence of an inductor L1 in the LED circuit, the current increases smoothly. As the current in the LED circuit increases, the voltage drop across the R5-R4 chain increases, as soon as it reaches about 0.4V, transistor T2 opens, followed by T1, which in turn closes the current switch T3. The increase in current stops, a self-induction current arises in the inductor, which begins to flow through the diode D1 through the LED and the chain of resistors R5-R4. As soon as the current decreases below a certain threshold, transistors T1 and T2 will close, T3 will open, which will lead to a new cycle of energy accumulation in the inductor. In normal mode, the oscillatory process occurs at a frequency of the order of tens of kilohertz.

About details:
Instead of the IRF510 transistor, you can use the IRF530, or any n-channel field-effect key transistor for a current of more than 3A and a voltage of more than 30 V.
Diode D1 must necessarily be with a Schottky barrier for a current of more than 1A, if you put an ordinary even high-frequency type KD212, the efficiency will drop to 75-80%.
The inductor is homemade, it is wound with a wire no thinner than 0.6 mm, better with a bundle of several thinner wires. About 20-30 turns of wire on the B16-B18 armor core are required with a non-magnetic gap of 0.1-0.2 mm or close to 2000NM ferrite. If possible, the thickness of the non-magnetic gap is selected experimentally according to the maximum efficiency of the device. Good results can be obtained with ferrites from imported inductors installed in switching power supplies, as well as in energy-saving lamps. Such cores have the form of a thread spool, do not require a frame and a non-magnetic gap. Coils on toroidal cores made of pressed iron powder, which can be found in computer power supplies (they are wound with output filter inductors), work very well. The non-magnetic gap in such cores is evenly distributed in volume due to the production technology.
The same stabilizer circuit can also be used in conjunction with other batteries and batteries of galvanic cells with a voltage of 9 or 12 volts without any change in the circuit or cell ratings. The higher the supply voltage, the less current the flashlight will consume from the source, its efficiency will remain unchanged. The stabilization current is set by resistors R4 and R5.
If necessary, the current can be increased up to 1A without the use of heat sinks on the parts, only by selecting the resistance of the setting resistors.
The charger for the battery can be left "native" or assembled according to any of the known schemes, or even use an external one to reduce the weight of the flashlight.



LED flashlight from calculator B3-30

The converter is based on the B3-30 calculator circuit, in the switching power supply of which a transformer with a thickness of only 5 mm is used, which has two windings. Using a pulse transformer from an old calculator made it possible to create an economical LED flashlight.

The result is a very simple circuit.


The voltage converter is made according to the scheme of a single-cycle generator with inductive feedback on a transistor VT1 and a transformer T1. The impulse voltage from the windings 1-2 (according to the B3-30 calculator circuit diagram) is rectified by the VD1 diode and fed to the super-bright HL1 LED. Capacitor C3 filter. The design is based on a Chinese-made flashlight designed to install two AA batteries. The transducer is mounted on a printed circuit board made of one-sided foil-coated fiberglass with a thickness of 1.5 mmfig.2sizes that replace one battery and inserted into the flashlight instead of it. A contact made of double-sided foil fiberglass with a diameter of 15 mm is soldered to the end of the board marked with a “+” sign, both sides are connected by a jumper and soldered.
After installing all the parts on the board, the “+” end contact and the T1 transformer are filled with hot glue to increase strength. The layout of the lantern is shown infig.3and in a particular case depends on the type of lamp used. In my case, no modification of the lamp was required, the reflector has a contact ring, to which the negative output of the printed circuit board is soldered, and the board itself is attached to the reflector with hot glue. The printed circuit board assembly with the reflector is inserted instead of one battery and clamped with a cover.

The voltage converter uses small parts. Resistors of the MLT-0.125 type, capacitors C1 and C3 are imported, up to 5 mm high. Diode VD1 type 1N5817 with a Schottky barrier, in its absence, you can use any rectifier diode that is suitable for the parameters, preferably germanium due to the lower voltage drop across it. A properly assembled converter does not need to be adjusted if the transformer windings are not reversed, otherwise swap them. In the absence of the above transformer, you can make it yourself. Winding is carried out on a ferrite ring of size K10 * 6 * 3 with a magnetic permeability of 1000-2000. Both windings are wound with PEV2 wire with a diameter of 0.31 to 0.44 mm. The primary winding has 6 turns, the secondary 10 turns. After installing such a transformer on the board and checking its performance, it should be fixed on it with hot glue.
Flashlight tests with an AA battery are presented in Table 1.
The test used the cheapest AA battery costing only 3 rubles. The initial voltage under load was 1.28 V. At the output of the converter, the voltage measured on a superbright LED was 2.83 V. The brand of the LED is unknown, the diameter is 10 mm. The total current consumption is 14 mA. The total operating time of the flashlight was 20 hours of continuous operation.
When the voltage on the battery drops below 1V, the brightness drops noticeably.

Time, h	V batteries, V	V conversion, V
0	1,28	2,83
2	1,22	2,83
4	1,21	2,83
6	1,20	2,83
8	1,18	2,83
10	1,18	2.83
12	1,16	2.82
14	1,12	2.81
16	1,11	2.81
18	1,11	2.81
20	1,10	2.80

Homemade flashlight with LEDs

The basis is a flashlight "VARTA" powered by two AA batteries:
Since diodes have a highly non-linear IV characteristic, it is necessary to equip the flashlight with a circuit for operating on LEDs, which will provide a constant brightness of the glow as the battery is discharged and will remain operational at the lowest possible supply voltage.
The heart of the voltage regulator is the MAX756 micropower DC/DC boost converter.
According to the declared characteristics, it works when the input voltage drops to 0.7V.

Switching scheme - typical:



Mounting is carried out in a hinged way.
Electrolytic capacitors - tantalum CHIP. They have a low series resistance, which improves efficiency somewhat. Schottky diode - SM5818. Chokes had to be connected in parallel, because. there was no suitable value. Capacitor C2 - K10-17b. LEDs - superbright white L-53PWC "Kingbright".
As you can see in the figure, the whole circuit easily fit into the empty space of the light emitting node.

The output voltage of the stabilizer in this switching circuit is 3.3V. Since the voltage drop across the diodes in the nominal current range (15-30mA) is about 3.1V, the extra 200mV had to be extinguished by a resistor connected in series with the output.
In addition, a small series resistor improves load linearity and circuit stability. This is due to the fact that the diode has a negative TCR, and when it is heated, the direct voltage drop decreases, which leads to a sharp increase in current through the diode when it is powered from a voltage source. It was not necessary to equalize the currents through the diodes connected in parallel - no difference in brightness was observed by eye. Moreover, the diodes were of the same type and taken from the same box.
Now about the design of the light emitter. As you can see in the photos, the LEDs in the circuit are not tightly soldered, but are a removable part of the structure.

The native light bulb is gutted, and 4 cuts are made in the flange from 4 sides (one was already there). 4 LEDs are arranged symmetrically in a circle. The positive leads (according to the diagram) are soldered to the base near the cuts, and the negative leads are inserted from the inside into the central hole of the base, cut off and also soldered. "Lamp diode", inserted in place of a conventional incandescent light bulb.

Testing:
The stabilization of the output voltage (3.3V) continued until the supply voltage dropped to ~1.2V. The load current in this case was about 100mA (~ 25mA per diode). Then the output voltage began to gradually decrease. The circuit has switched to a different mode of operation, in which it no longer stabilizes, but outputs everything it can. In this mode, it worked up to a supply voltage of 0.5V! The output voltage at the same time dropped to 2.7V, and the current from 100mA to 8mA.

A little about efficiency.
The efficiency of the circuit is about 63% with fresh batteries. The fact is that the miniature chokes used in the circuit have an extremely high ohmic resistance - about 1.5 ohm
The solution is a µ-permalloy ring with a permeability of about 50.
40 turns of PEV-0.25 wire, in one layer - it turned out about 80 μG. The active resistance is about 0.2 Ohm, and the saturation current, according to calculations, is more than 3A. We change the output and input electrolyte to 100 microfarads, although without prejudice to efficiency it can be reduced to 47 microfarads.


Scheme of the LED lampon DC/DC converter from Analog Device - ADP1110.



Standard typical connection diagram of ADP1110.
This converter chip, according to the manufacturer's specifications, is available in 8 versions:

Model	Output voltage
ADP1110AN	Adjustable
ADP1110AR	Adjustable
ADP1110AN-3.3	3.3V
ADP1110AR-3.3	3.3V
ADP1110AN-5	5V
ADP1110AR-5	5V
ADP1110AN-12	12V
ADP1110AR-12	12V

Microcircuits with indices "N" and "R" differ only in the type of package: R is more compact.
If you bought a chip with an index of -3.3, you can skip the next paragraph and go to the "Details" item.
If not, I present to your attention another scheme:



It adds two parts to get the required 3.3 volts output to power the LEDs.
The circuit can be improved by taking into account that the LEDs need a current source, not a voltage source, to operate. Changes in the circuit so that it would give out 60mA (20 for each diode), and the diodes will automatically set the voltage to us, the same 3.3-3.9V.




resistor R1 is used to measure the current. The converter is designed in such a way that when the voltage at the FB (Feed Back) pin exceeds 0.22V, it will finish increasing the voltage and current, which means that the value of the resistance R1 is easy to calculate R1 = 0.22V / In, in our case 3.6Ω. Such a circuit helps to stabilize the current, and automatically select the required voltage. Unfortunately, voltage will drop across this resistance, which will lead to a decrease in efficiency, however, practice has shown that it is less than the excess that we chose in the first case. I measured the output voltage and it was 3.4 - 3.6V. The parameters of the diodes in such an inclusion should also be as similar as possible, otherwise the total current of 60mA was not distributed equally between them, and again we will get different luminosity.

Details
1. A choke will fit any 20 to 100 microhenry with a small (less than 0.4 ohm) resistance. The diagram indicates 47 μH. You can make it yourself - wind about 40 turns of PEV-0.25 wire on a µ-permalloy ring with a permeability of about 50, size 10x4x5.
2. Schottky diode. 1N5818, 1N5819, 1N4148 or equivalent. Analog Device DOES NOT RECOMMEND the use of the 1N4001
3. Capacitors. 47-100 microfarads at 6-10 volts. It is recommended to use tantalum.
4. Resistors. A power of 0.125 watts with a resistance of 2 ohms, possibly 300 kΩ and 2.2 kΩ.
5. LEDs. L-53PWC - 4 pieces.



Voltage converter for powering a white LED DFL-OSPW5111P with a brightness of 30 cd at a current of 80 mA and a radiation pattern width of about 12°.


The current consumed from a battery with a voltage of 2.41V is 143mA; in this case, a current of about 70 mA flows through the LED at a voltage of 4.17 V on it. The converter operates at a frequency of 13 kHz, the electrical efficiency is about 0.85.
Transformer T1 is wound on an annular magnetic circuit of size K10x6x3 made of ferrite 2000NM.

The primary and secondary windings of the transformer are wound simultaneously (i.e., in four wires).
The primary winding contains - 2x41 turns of wire PEV-2 0.19,
The secondary winding contains - 2x44 turns of wire PEV-2 0.16.
After winding, the winding leads are connected in accordance with the diagram.

Transistors KT529A of the p-n-p structure can be replaced with KT530A of the n-p-n structure, in this case it is necessary to change the polarity of connecting the GB1 battery and the HL1 LED.
Details are placed on the reflector using hanging mounting. Pay attention to the fact that the contact of the parts with the tin plate of the flashlight, which supplies the "minus" of the GB1 battery, is excluded. The transistors are fastened together with a thin brass clamp, which provides the necessary heat removal, and then glued to the reflector. The LED is placed instead of the incandescent lamp so that it protrudes 0.5 ... 1 mm from the socket for its installation. This improves heat dissipation from the LED and simplifies its installation.
When you first turn on the battery power is supplied through a resistor with a resistance of 18 ... 24 ohms so as not to damage the transistors if the terminals of the transformer T1 are connected incorrectly. If the LED does not shine, it is necessary to swap the extreme terminals of the primary or secondary winding of the transformer. If this does not lead to success, check the serviceability of all elements and the correct installation.


Voltage converter for powering an industrial design LED lamp.




Voltage converter for powering the LED lamp
The circuit is taken from the Zetex manual for the use of ZXSC310 microcircuits.
ZXSC310- LED driver chip.
FMMT 617 or FMMT 618.
Schottky diode- almost any brand.
Capacitors C1 = 2.2uF and C2 = 10uFfor surface mounting, 2.2 uF is the value recommended by the manufacturer, and C2 can be set from about 1 to 10 uF

Inductor 68 microhenries at 0.4 A

The inductance and resistor are installed on one side of the board (where there is no print), all other parts are on the other. The only trick is making a 150 milliohm resistor. It can be made from 0.1 mm iron wire, which can be obtained by unwinding the cable. The wire should be annealed on a lighter, carefully wiped with a fine sandpaper, tinned the ends and soldered a piece about 3 cm long into the holes on the board. Further, in the process of tuning, it is necessary, by measuring the current through the diodes, to move the wire, while heating the place of its soldering to the board with a soldering iron.

Thus, something like a rheostat is obtained. Having achieved a current of 20 mA, the soldering iron is removed, and an unnecessary piece of wire is cut off. The author came out with a length of about 1 cm.


Flashlight on power source


Rice. 3.A flashlight on a current source, with automatic current equalization in the LEDs, so that the LEDs can be with any spread of parameters (the VD2 LED sets the current that the transistors VT2, VT3 repeat, so the currents in the branches will be the same)
Transistors, of course, should also be the same, but the spread of their parameters is not so critical, so you can take either discrete transistors, or if you can find three integrated transistors in one package, their parameters are as close as possible. Play with the placement of the LEDs, you need to choose a pair of LED-transistor so that the output voltage is minimal, this will increase the efficiency.
The introduction of transistors evened out the brightness, but they have resistance and voltage drops on them, which forces the converter to increase the output level to 4V, to reduce the voltage drop across the transistors, you can propose a circuit in Fig. 4, this is a modified current mirror, instead of the reference voltage Ube = 0.7V in the circuit in Fig. 3, you can use the 0.22V source built into the converter, and maintain it in the VT1 collector using an op-amp, also built into the converter.



Rice. 4.Flashlight on a power source, with automatic current equalization in the LEDs, and with improved efficiency

Because the output of the opamp is of the “open collector” type; it must be “pulled up” to the power supply, which makes the resistor R2. Resistors R3, R4 act as a voltage divider at point V2 by 2, so the opamp will maintain a voltage of 0.22 * 2 = 0.44V at point V2, which is 0.3V less than in the previous case. It is impossible to take a divider even less in order to lower the voltage at point V2. the bipolar transistor has a resistance Rke and during operation, the voltage Uke will drop on it, so that the transistor works correctly V2-V1 must be greater than Uke, for our case 0.22V is enough. However, bipolar transistors can be replaced with field-effect transistors, in which the drain-to-source resistance is much less, this will make it possible to reduce the divider, so that the difference V2-V1 is completely insignificant.

Throttle.The inductor must be taken with a minimum resistance, special attention should be paid to the maximum allowable current, it should be of the order of 400 -1000 mA.
The rating doesn't matter as much as the maximum current, so Analog Devices recommends something between 33 and 180uH. In this case, theoretically, if you do not pay attention to the dimensions, then the larger the inductance, the better in all respects. However, in practice this is not entirely true, because. we have a non-ideal coil, it has active resistance and is not linear, in addition, the key transistor at low voltages will no longer give out 1.5A. Therefore, it is better to try several coils of different types, designs and different ratings in order to choose a coil with the highest efficiency and the smallest minimum input voltage, i.e. the coil with which the flashlight will glow for as long as possible.

Capacitors.C1 can be anything. C2 is better to take tantalum because. it has a small resistance, which increases the efficiency.

Schottky diode.Any for current up to 1A, preferably with minimal resistance and minimal voltage drop.

Transistors.Any with collector current up to 30 mA, coefficient current amplification of the order of 80 with a frequency of up to 100 MHz, KT318 is suitable.

LEDs.You can white NSPW500BS with a glow of 8000mCd from Power Light Systems.

Voltage transformerADP1110, or its replacement ADP1073, to use it, the circuit in Fig. 3 will need to be changed, take a 760μG inductor, and R1 = 0.212 / 60mA = 3.5Ω.


Lantern on ADP3000-ADJ

Options:
Power supply 2.8 - 10 V, efficiency approx. 75%, two brightness modes - full and half.
The current through the diodes is 27 mA, in half brightness mode - 13 mA.
In order to obtain high efficiency, it is desirable to use chip components in the circuit.
A properly assembled circuit does not need to be configured.
The disadvantage of the circuit is the high (1.25V) voltage at the FB input (pin 8).
Currently, DC / DC converters with an FB voltage of about 0.3V are being produced, in particular, by Maxim, on which it is realistic to achieve an efficiency above 85%.


Scheme of a lantern on Kr1446PN1.




Resistors R1 and R2 - current sensor. Operational amplifier U2B - amplifies the voltage taken from the current sensor. The gain = R4 / R3 + 1 and is approximately 19. The gain is required so that when the current through the resistors R1 and R2 is 60 mA, the output voltage opens the transistor Q1. By changing these resistors, you can set other stabilization current values.
In principle, an operational amplifier can be omitted. It’s just that instead of R1 and R2 one 10 Ohm resistor is placed, from it the signal through the 1kOhm resistor is fed to the base of the transistor and that’s it. But. This will lead to a decrease in efficiency. On a 10 ohm resistor at a current of 60 mA, 0.6 volts - 36 mW is wasted in vain. In the case of using an operational amplifier, the losses will be:
on a 0.5 Ohm resistor at a current of 60 mA = 1.8 mW + the consumption of the op-amp itself is 0.02 mA, let at 4 Volts = 0.08 mW
= 1.88 mW - significantly less than 36 mW.

About components.

In place of KR1446UD2, any low-power op-amp with a low minimum supply voltage can work, OP193FS would be better, but it is quite expensive. Transistor in SOT23 package. The polar capacitor is smaller - type SS at 10 Volts. Inductance CW68 100uH for 710mA. Although the cutoff current of the converter is 1 A, it works normally. It has the best efficiency. I selected the LEDs for the most identical voltage drop at a current of 20 mA. Assembled a flashlight in a case for two AA batteries. I shortened the place for the batteries to fit the size of AAA batteries, and in the freed space I assembled this circuit by surface mounting. A case for three AA batteries will work well. You will need to install only two, and place the scheme in place of the third.

The efficiency of the resulting device.
Input U I P Output U I P Efficiency
Volt mA mW Volt mA mW %
3.03 90 273 3.53 62 219 80
1.78 180 320 3.53 62 219 68
1.28 290 371 3.53 62 219 59

Replacing the light bulb of the flashlight “Zhuchok” with a module from the companyLuxionLumiledLXHL-NW 98.
We get a dazzlingly bright flashlight, with a very light press (compared to a light bulb).


Modification scheme and module parameters.

StepUP DC-DC converters ADP1110 from Analog devices.




Power supply: 1 or 2 batteries 1.5V operability is maintained up to Uin.=0.9V
Consumption:
*with open switch S1 = 300mA
*with switch closed S1 = 110mA


LED electronic flashlight
Powered by just one AA or AAA finger-type battery on a microcircuit (KR1446PN1), which is a complete analogue of the MAX756 microcircuit (MAX731) and has almost identical characteristics.


A flashlight is taken as a basis, in which two AA batteries (accumulators) are used as a power source.
The converter board is placed in the lantern instead of the second battery. On one end of the board, a tinned sheet contact is soldered to power the circuit, and on the other, an LED. A circle of the same tin is put on the conclusions of the LED. The diameter of the circle should be slightly larger than the diameter of the reflector base (by 0.2-0.5 mm), into which the cartridge is inserted. One of the terminals of the diode (negative) is soldered to the mug, the second (positive) passes through and is insulated with a piece of PVC or fluoroplastic tubing. The purpose of the circle is twofold. It provides the structure with the necessary rigidity and at the same time serves to close the negative contact of the circuit. A lamp with a cartridge is removed from the lantern in advance and a circuit with an LED is placed instead. Before installation on the board, the LED leads are shortened in such a way as to ensure a tight, play-free fit “in place”. Typically, the length of the leads (excluding soldering to the board) is equal to the length of the protruding part of the fully screwed lamp base.
The connection diagram of the board and the battery is shown in fig. 9.2.
Next, the lantern is assembled and its performance is checked. If the circuit is assembled correctly, then no settings are required.

The design uses standard installation elements: capacitors of the K50-35 type, EC-24 chokes with an inductance of 18-22 μH, LEDs with a brightness of 5-10 cd with a diameter of 5 or 10 mm. Of course, it is also possible to use other LEDs with a supply voltage of 2.4-5 V. The circuit has a sufficient power reserve and allows you to power even LEDs with a brightness of up to 25 cd!

On some test results of this design.
The lantern modified in this way worked with a “fresh” battery without interruption, in the switched on state, for more than 20 hours! For comparison, the same flashlight in the "standard" configuration (that is, with a lamp and two "fresh" batteries from the same batch) worked for only 4 hours.
And one more important point. If rechargeable batteries are used in this design, it is easy to monitor the state of their discharge level. The fact is that the converter on the KR1446PN1 chip starts stably at an input voltage of 0.8-0.9 V. And the glow of the LEDs is consistently bright until the battery voltage reaches this critical threshold. The lamp will still burn at this voltage, of course, but it is hardly possible to speak of it as a real light source.

Rice. 9.2Figure 9.3




The printed circuit board of the device is shown in fig. 9.3, and the location of the elements - in fig. 9.4.


Turning the flashlight on and off with one button


The circuit is assembled on a CD4013 D-trigger chip and an IRF630 field effect transistor in the "off" mode. the current consumption of the circuit is practically 0. For stable operation of the D-flip-flop, a filter resistor and a capacitor are connected to the input of the microcircuit, their function is to eliminate contact bounce. It is better not to connect unused microcircuit pins anywhere. The microcircuit operates from 2 to 12 volts; any powerful field-effect transistor can be used as a power switch, because. the drain-source resistance of the field-effect transistor is negligible and does not load the output of the microcircuit.

CD4013A in SO-14 package, analogue to K561TM2, 564TM2

Simple generator circuits.
Allow to feed the LED with ignition voltage 2-3V from 1-1.5V. Short pulses of increased potential open the p-n junction. The efficiency of course decreases, but this device allows you to "squeeze out" almost all of its resource from an autonomous power source.
Wire 0.1 mm - 100-300 turns with a tap from the middle, wound on a toroidal ring.




Dimmable LED flashlight with beacon mode

The power supply of the microcircuit - a generator with an adjustable duty cycle (K561LE5 or 564LE5) that controls the electronic key, in the proposed device is carried out from a step-up voltage converter, which allows the lamp to be powered from one galvanic cell 1.5.
The converter is made on transistors VT1, VT2 according to the transformer oscillator circuit with positive current feedback.
The oscillator circuit with an adjustable duty cycle on the K561LE5 chip mentioned above has been slightly modified in order to improve the linearity of current regulation.
The minimum current consumption of the flashlight with six parallel-connected super-bright LEDs L-53MWC by Kingbnght of white light is 2.3 mA. The dependence of the consumed current on the number of LEDs is directly proportional.
The "Beacon" mode, when the LEDs flash brightly at a low frequency and then go out, is implemented by setting the brightness control to maximum and turning on the flashlight again. The desired frequency of light flashes is regulated by the selection of the capacitor C3.
The flashlight remains operational when the voltage drops to 1.1v, although the brightness decreases significantly
A field-effect transistor with an insulated gate KP501A (KR1014KT1V) was used as an electronic key. In terms of the control circuit, it is in good agreement with the K561LE5 microcircuit. The KP501A transistor has the following limiting parameters, the drain-source voltage is 240 V; gate-source voltage - 20 V. drain current - 0.18 A; power - 0.5 W
It is permissible to connect transistors in parallel, preferably from the same batch. Possible replacement - KP504 with any letter index. For field-effect transistors IRF540, the supply voltage of the DD1. generated by the converter must be increased to 10 V
In a lamp with six L-53MWC LEDs connected in parallel, the current consumption is approximately equal to 120 mA when the second transistor is connected in parallel to VT3 - 140 mA
Transformer T1 is wound on a ferrite ring 2000NM K10-6 "4.5. The windings are wound in two wires, and the end of the first winding is connected to the beginning of the second winding. The primary winding contains 2-10 turns, the secondary - 2 * 20 turns Wire diameter - 0.37 mm. brand - PEV-2. The inductor is wound on the same magnetic circuit without a gap with the same wire in one layer, the number of turns is 38. The inductance of the inductor is 860 μH












Converter circuit for LED from 0.4 to 3V- powered by one AAA battery. This flashlight increases the input voltage to the required voltage with a simple DC-DC converter.






The output voltage is approximately 7 watts (depending on the voltage of the installed LEDs).

Building the LED Head Lamp





As for the transformer in the DC-DC converter. You must make it yourself. The image shows how to assemble the transformer.



Another version of converters for LEDs _http://belza.cz/ledlight/ledm.htm








Flashlight on a lead-acid sealed battery with a charger.

Lead acid sealed batteries are currently the cheapest. The electrolyte in them is in the form of a gel, so the batteries allow operation in any spatial position and do not produce any harmful fumes. They are characterized by great durability, if you do not allow deep discharge. Theoretically, they are not afraid of overcharging, but this should not be abused. Batteries can be recharged at any time without waiting for them to be completely discharged.
Lead-acid sealed batteries are suitable for use in portable flashlights used in the household, in summer cottages, and in production.


Fig.1. Diagram of an electric lantern

The electrical circuit diagram of a flashlight with a charger for a 6-volt battery, which allows in a simple way to prevent deep discharge of the battery and thus increase its service life, is shown in the figure. It contains a factory-made or self-made transformer power supply and a charger-switching device mounted in the lamp housing.
In the author's version, a standard block designed to power modems is used as a transformer unit. The output AC voltage of the block is 12 or 15 V, the load current is 1 A. There are also such blocks with built-in rectifiers. They are also suitable for this purpose.
The alternating voltage from the transformer unit is supplied to the charging and switching device, which contains a plug for connecting the charger X2, a diode bridge VD1, a current stabilizer (DA1, R1, HL1), a GB battery, a toggle switch S1, an emergency power button S2, an incandescent lamp HL2. Each time the toggle switch S1 is turned on, the battery voltage is supplied to the relay K1, its contacts K1.1 close, supplying current to the base of the transistor VT1. The transistor turns on by passing current through the lamp HL2. The lamp is turned off by switching the toggle switch S1 to its original position, in which the battery is disconnected from the winding of relay K1.
The permissible battery discharge voltage is selected at the level of 4.5 V. It is determined by the turn-on voltage of relay K1. You can change the allowable value of the discharge voltage using the resistor R2. With an increase in the value of the resistor, the allowable discharge voltage increases, and vice versa. If the battery voltage is below 4.5 V, then the relay will not turn on, therefore, voltage will not be applied to the base of the transistor VT1, which turns on the HL2 lamp. This means that the battery needs to be charged. At a voltage of 4.5 V, the illumination created by the flashlight is not bad. In case of emergency, you can turn on the flashlight at low voltage with the S2 button, provided that the S1 toggle switch is first turned on.
A constant voltage can also be applied to the input of the charging-switching device, without paying attention to the polarity of the connected devices.
To transfer the flashlight to the charge mode, it is necessary to dock the X1 socket of the transformer unit with the X2 plug located on the lamp body, and then plug the plug (not shown in the figure) of the transformer unit into the 220 V network.
In the above embodiment, a 4.2 Ah battery is used. Therefore, it can be charged with a current of 0.42 A. The battery is charged with direct current. The current stabilizer contains only three parts: an integrated voltage regulator DA1 type KR142EN5A or imported 7805, an HL1 LED and a resistor R1. The LED, in addition to working in a current stabilizer, also performs the function of an indicator of the battery charge mode.
Setting up the electrical circuit of the flashlight is reduced to adjusting the current of the battery charge. The charging current (in amperes) is usually chosen ten times less than the numerical value of the battery capacity (in ampere-hours).
For tuning, it is best to assemble the current stabilizer circuit separately. Instead of a battery load, connect an ammeter for a current of 2 ... 5 A to the connection point of the cathode of the LED and resistor R1. By selecting resistor R1, set the calculated charge current using the ammeter.
Relay K1 - reed switch RES64, passport RS4.569.724. The HL2 lamp consumes a current of approximately 1A.
The KT829 transistor can be used with any letter index. These transistors are composite and have a high current gain of 750. This should be taken into account in case of replacement.
In the author's version, the DA1 chip is installed on a standard ribbed heatsink with dimensions of 40x50x30 mm. Resistor R1 consists of two 12W wirewound resistors connected in series.

Scheme:



REPAIR OF LED FLASHLIGHT

Part ratings (C, D, R)
C = 1 uF. R1 = 470 kOhm. R2 = 22 kOhm.
1D, 2D - KD105A (admissible voltage 400V limit current 300 mA.)
Provides:
charging current = 65 - 70mA.
voltage = 3.6V.











LED Treiber PR4401 SOT23

Here you can see what the results of the experiment led to.

The scheme offered to your attention was used to power an LED flashlight, recharge a mobile phone from two metal hydrite batteries, when creating a microcontroller device, a radio microphone. In each case, the operation of the circuit was flawless. The list where you can use the MAX1674 can be continued for a long time.


The easiest way to get a more or less stable current through the LED is to connect it to the unregulated power circuit through a resistor. Keep in mind that the supply voltage must be at least twice the operating voltage of the LED. The current through the LED is calculated by the formula:
I led \u003d (Umax. supply - U working diode) : R1

This scheme is extremely simple and in many cases justified, but it should be used where there is no need to save electricity, and there are no high requirements for reliability.
More stable circuits - based on linear stabilizers:


As stabilizers, it is better to choose adjustable, or fixed voltage, but it should be as close as possible to the voltage on the LED or a string of LEDs connected in series.
Stabilizers like LM 317 are very suitable.
German text: iel war es, mit nur einer NiCd-Zelle (AAA, 250mAh) eine der neuen ultrahellen LEDs mit 5600mCd zu betreiben. Diese LEDs benötigen 3,6V/20mA. Ich habe Ihre Schaltung zunächst unverändert übernommen, als Induktivität hatte ich allerdings nur eine mit 1,4mH zur Hand. Die Schaltung lief auf Anhieb! Allerdings ließ die Leuchtstärke doch noch zu wünschen übrig. Mehr zufällig stellte ich fest, dass die LED extrem heller wurde, wenn ich ein Spannungsmessgerät parallel zur LED schaltete!??? Tatsächlich waren es nur die Messschnüre, bzw. deren Kapazität, die den Effekt bewirkten. Mit einem Oszilloskop konnte ich dann feststellen, dass in dem Moment die Frequenz stark anstieg. Hm, also habe ich den 100nF-Condensator gegen einen 4.7nF Typ ausgetauscht und schon war die Helligkeit wie gewünscht. Anschließend habe ich dann nur noch durch Ausprobieren die beste Spule aus meiner Sammlung gesucht... Das beste Ergebnis hatte ich mit einem alten Sperrkreis für den 19KHz Pilotton (UKW), aus dem ich die Kreiskapazität entfernt habe. Und hier ist sie nun, die Mini-Taschenlampe:

Sources:
http://pro-radio.ru/
http://radiokot.ru/

More recently, the word LED was associated only with indicator devices. Since they were quite expensive and emitted only a few colors, they also shone faintly. With the development of technology, the price of LED products has gradually decreased, the scope of application has expanded in leaps and bounds.

Today they are used in various devices, they are used almost everywhere where lighting devices are needed. Headlights and lamps in cars are equipped with LEDs, advertising on billboards is highlighted by LED strips. At home, they are also no less often used.

Reasons for using LEDs

Not spared and lanterns. Thanks to powerful LEDs, it became possible to assemble a heavy-duty and at the same time quite autonomous flashlight. Such lanterns can emit very strong and bright light over a long distance or over a large area.

In this article, we will tell you about the main advantages of high power LEDs, and tell you how to fold an LED flashlight with your own hands. If you have already encountered this, then you can supplement your knowledge, for beginners in this area, the article will answer many questions related to LEDs and lanterns with their application.

If you want to save money by using an LED, there are a few things to consider. Since sometimes the price of such a lamp can exceed all the savings. If, on the other hand, you have to spend a lot of money and time maintaining lights, and the total amount of them consumes a lot of electricity, then you should consider whether an LED would be a better replacement.

Compared to conventional lamps, the LED has a number of advantages that elevate it:

• There is no need for maintenance.
• Significant energy savings, sometimes saving up to 10 times.
• High quality light output.
• Very high service life.

Necessary components

If you decide to assemble an LED flashlight with your own hands, for moving in the dark or for working at night, but do not know where to start? You will help you with this. The first thing to do is to find the necessary elements for assembly.

Here is a preliminary list of required parts:

1. Light-emitting diode
2. Winding wire, 20-30 cm.
3. Ferrite ring approximately 1-.1.5 cm in diameter.
4. Transistor.
5. 1000 ohm resistor.

Of course, this list also needs to be supplemented with a battery, but this is an element that can be easily found in any home and does not require special preparation. You should also choose a case or some kind of base on which the entire circuit will be installed. A good case would be an old non-working flashlight or one that you are going to modify.

How to assemble with your own hands

When assembling the circuit, we will need a transformer, but it was not added to the list. We will make it with our own hands from a ferrite ring and wire. It is very simple to do this, we take our ring and start winding the wire forty-five times, this wire will be connected to the LED. We take the next wire, and wind it thirty times already, and send it to the base of the transistor.

The resistor used in the circuit must have a resistance of 2000 ohms, only using such a resistance, the circuit will be able to work without failure. When testing the circuit, replace the resistor R1 with a similar one with adjustable resistance. Turn on the entire circuit and adjust the resistance of this resistor, adjust the voltage to around 25mA.

As a result, you will find out what resistance should be at this point, and you will be able to choose a suitable resistor, with the resistance value you need.

If the circuit is drawn up in full accordance with the above requirements, then the lamp should work immediately. If it doesn't work, then you may have made the following mistake:

• The ends of the winding are connected in reverse.
• The number of turns is not correct.
• If there are less than 15 wound turns, then the current generation in the transformer ceases to be carried out.

Assembling a 12 volt LED flashlight

If the amount of light from the flashlight is not enough, then you can assemble a powerful flashlight powered by a 12 volt battery. Such a flashlight is still portable, but much larger in size.

To assemble the circuit of such a lantern with our own hands, we need the following parts:

1. Plastic pipe, about 5 cm in diameter and PVC glue.
2. Threaded fitting for PVC, two pieces.
3. Threaded plug.
4. Tumbler.
5. Actually the LED lamp itself, designed for 12 volts.
6. Battery for powering the LED, 12 volts.

Insulating tape, heat shrink tubing and small clamps to tidy up the wiring.
The battery can be made by hand, from small batteries that are used in radio-controlled toys. You may need 8-12pcs, depending on their power, so that in total you get 12 volts.

To the contacts on the light bulb, solder two wires, the length of each should exceed the length of the battery by several centimeters. Everyone is carefully isolated. When connecting the lamp and battery, install the toggle switch in such a way that it is located at the opposite end from the LED lamp.

At the ends of the wires coming from the lamp and from the battery pack, which we made with our own hands, we install special connectors for easy connection. We collect the entire circuit and check its performance.

Assembly diagram

If everything works, then proceed to the creation of the case. Having cut off the required length of the pipe, we insert our entire structure into it. Accumulator We carefully fix it inside with glue so that it does not damage the light bulb during operation.

We install a fitting at both ends, fasten it with glue, so we will protect the lantern from accidental moisture getting inside. Next, we bring our toggle switch to the opposite edge from the lamp, and also carefully fix it. The rear fitting must completely cover the switch with its walls, and when the plug is screwed in, prevent moisture from entering there.

To use, just unscrew the cap, turn on the flashlight and tighten it again tightly.

price issue

The most expensive thing you will need is a 12 volt LED lamp. It costs about 4-5 dollars. After digging through old toys of children, batteries from a broken car will be free for you.

A toggle switch and a pipe can also be found in the garage; cuts of such pipes constantly remain after repairs. If there are no pipes and batteries, you can ask friends and neighbors or buy in a store. If you buy absolutely everything, then such a flashlight can cost you about $ 10.

Summarize

LED technology is gaining more and more popularity. Having good characteristics, they can soon completely displace all competitors in the field of lighting. And to assemble a powerful portable flashlight with an LED lamp with your own hands will not be difficult for you.

In this article, we will look at how you can make a powerful LED-based flashlight yourself with your own hands. It will consume much less energy than a regular one.
Today it is quite difficult to buy a quality LED flashlight at a good price. Therefore, we suggest saddling it with your own hands. It is quite easy to make a powerful LED flashlight yourself. The total cost of manufacturing a lantern will be less than what you would pay for a similar factory lantern. It takes a little patience and a great desire, as well as a couple of tools. You can use this device for various purposes: in the garden or in the garden, near the house, to illuminate furniture, as headlights for a car, and even for scuba diving!

To create a DIY LED flashlight, you will need:

• non-working flashlight
• several LED bulbs;
• resistors;
• adhesive - sealant or silicone adhesive of good quality;
• the plate is preferably made of aluminum, but you can take another durable material;
• any reflector.

The main stages of our work:

1. Drawing up an electrical circuit
2. Fabrication and preparation of a plate for LEDs
3. Circuit Assembly
   3.1 Soldering lamp leads
   3.2 Filling contacts and checking them
4. Work with a reflector (preparation and assembly)
5. Fixing all parts of the LED flashlight

So let's get started. The first step is to make a wiring diagram for resistors and LEDs. Lack of knowledge and experience in working with electricity is not a problem. You can complete the scheme by reading the information on Internet sites or through online programs. As a result, following the instructions, you will receive a finished project on the screen.

For the correct modeling and manufacturing of the circuit, it is necessary to clearly determine the voltage strength of the power source and LED lamps, the number of LEDs and the current strength of one LED. All these parameters are indicated in the characteristics and descriptions in the instructions for parts.

The first stage of making an LED flashlight with your own hands is completed. We proceed to the next - the manufacture of the plate. This plate will be used as a holder. First, draw on a piece of paper a preliminary diagram of the plate with all the holes for the LEDs. There should be as many holes as there are LEDs. Then cut out the diagram with scissors and glue it to the plate. According to the sketch that is printed on paper, make the corresponding holes in the plate. It will be convenient and easy to do this with a drill.

Next, stretch all the LEDs into the resulting holes. It is important not to hook or damage the contacts. Make sure that cathodes and anodes alternate! All this is desirable to do on a flat surface. As a result, the LEDs should, as it were, “fall through” into the holes. Don't forget to secure the LED bulbs with glue or sealant for added strength and durability.

The third stage of creating a do-it-yourself LED flashlight begins with one more additional layer of glue. Now solder the LEDs and resistors with a regular blowtorch. Take care not to damage or touch the contacts. Remember that before soldering all the tips of the LED bulbs must be shortened. First, mark the positive and negative conclusions so that they are not confused.
Alternatively, you can simply make the negative output a little shorter. It won't affect the quality. Now solder the leads.

Checking and filling contacts is an important step when assembling an LED flashlight. Before proceeding with this task, test the operation of the already received device by connecting it to power. All lamps must be lit. Now we fill in the contacts. It is convenient to do this with ordinary wax or use paraffin. It is best to squeeze out the wax with a syringe so that the contacts do not come into contact with each other. This is a short circuit precaution.

We proceed to work with a reflector. It increases the power of the LED flashlight. Remove the halogen bulb from the reflector. We also recommend cleaning it of the resin on which the lamp was held.
Assembling the LED lamp is the penultimate stage of work on the DIY LED flashlight. To do this, securely fix all contacts. Make sure everything is tight!

Finally, we have come to the end of creating an LED flashlight with our own hands. Molten plastic is needed to fill the contacts. The wax that was used earlier is not suitable, since high reliability and strength are needed here. We solder to a power source, for example, to a regular battery, or to a plug.

After the plastic hardens, cut off the excess leads. Then reconnect the received device to power. If there are no signs of a short circuit within 2 minutes, confidently install the DIY LED flashlight in any place.

As a rule, from electric lamps it is desirable to obtain the maximum brightness of the glow. However, sometimes lighting is required that will minimally disrupt vision adaptation to darkness. As you know, the human eye can change its photosensitivity over a fairly wide range. This allows, on the one hand, to see at dusk and in poor light, and on the other hand, not to go blind on a bright sunny day. If at night you go out of a well-lit room into the street, then for the first moments almost nothing will be visible, but gradually your eyes will adapt to new conditions. Full adaptation of vision to the dark takes about one hour, after which the eye reaches its maximum sensitivity, which is 200 thousand times higher than daylight. In such conditions, even short-term exposure to bright light (turning on a flashlight, car headlights) greatly reduces the sensitivity of the eyes. However, even with full adaptation to the dark, it may be necessary, for example, to read a map, illuminate the scale of the device, and the like, and this requires artificial lighting. Therefore, lovers of astronomy, as well as anyone who needs to consider something in poor lighting conditions, do not need a bright flashlight.

In the manufacture of an astronomical lantern, one should not strive for excessive miniaturization. The body of an astronomical flashlight should be light and large enough so that in poor lighting conditions it can be easily found (otherwise you will drop it under your feet and look for a flashlight for half an hour). A road soap dish was used as a case. Switches should be such that they can be easily operated by touch and with gloves.

The eye is maximally sensitive to light from a long wavelength of 550 nm (green light), and in the dark, the maximum sensitivity of the eye shifts towards short wavelengths up to 510 nm (effect Purkinje). Therefore, it is preferable to use red LEDs in an astronomical lantern, and not blue, or even more so green. To red light, the sensitivity of the eyes is less, which means that red lighting will less disrupt adaptation to the dark.

In addition to the main lantern, you can make several simple beacons to illuminate various objects. The fact is that few astronomy lovers can afford to have a full-fledged amateur observatory. Most are watching from the balcony. And in a tight space, and even in the dark, you can easily catch your foot and fill up the tripod of a telescope or camera. In addition, suddenly meet in the dark knee with the corner of a drawer or bedside table, the same pleasure is small. Therefore, it is advisable to use the simplest mini flashlights to illuminate tripod legs, sharp corners of furniture, shelves with accessories, and so on. In principle, just an LED fixed with adhesive tape on a 3 V battery of the type 2032 or similar. But, firstly, without a current-limiting resistor, the LED glow is too bright, and secondly, it is desirable to have a switch even in the simplest flashlight. Guided by these considerations, several such beacons were made.

A reed switch paired with a magnet is used as a switch. The 3 V battery mount is self-made. A current-limiting resistor is switched on in series with the LED, its value must be selected so that in the dark, with a direct look at the LED lens, the light does not blind the eyes even at close range. In different beacons, you can use LEDs of different colors to facilitate identification, while remembering that the eye does not have the same sensitivity to light with different wavelengths. You can use flashing LEDs.

In addition, a couple more designs of simple LED lights. The structures specifically described below were not intended for astronomical purposes, but they can easily be adapted for such use.

A simple waterproof flashlight can be made from a film can. We will need: a new jar of film, a 3 V LED, 2-3 reed switches, a 3 V lithium battery 2032 , cotton wool (case filler), a block for a battery from an old flashlight. To ensure water resistance, it is necessary that there are no holes in the body of the flashlight. So as a switch, you can use sealed contacts. For reliable operation, it is better to take 2-3 reed switches, since when turning along the longitudinal axis, the sensitivity of the reed switch changes. So, we collect a flashlight according to the scheme.

We bend the wires so that everything fits in the case, I filled the empty space with cotton so that nothing dangles. We place the circuit in the case. It is important that the film jar is new, i.e. so that the lid closes as tightly as possible. Any magnet will work as a switch. The flashlight of this design continued to work after 10 hours in the water. The cotton wool remained dry. So, long-term lying in a puddle will not damage such a device.

Surely radio amateurs have pads from failed 9 V batteries of the Krona type. On the basis of such a block, you can assemble a simple flashlight that does not actually need a body. An LED is connected to the contacts of the block through a current-limiting resistor.

Outside, the LED and resistor are wrapped with several layers of insulating tape. In the position put on the battery, the flashlight forms a single unit with it.

Thus, it is possible to adapt almost any suitable case and battery for a homemade flashlight, although below 3.5 V you will already need to install LEDs. Thank you for your attention. Author Denev.

Discuss the article LED FLASHLIGHTS WITH YOUR HANDS

At the time of the hobby for tourism, a Duracell flashlight was purchased with a powerful krypton lamp on two large D-size batteries (in the Soviet version, type 373). The light was excellent, but the batteries landed in 3-4 hours.

In addition, trouble happened twice - the batteries leaked and everything inside the flashlight was flooded with electrolyte. The contacts oxidized, rusted, and even after cleaning and installing new batteries, the flashlight no longer inspired confidence, and even more so the batteries. It was a pity to throw it away, and not having the opportunity to use it, prompted the idea to convert the flashlight to the now fashionable lithium battery and LED. For half a year, a Sanyo 18650 lithium battery with a capacity of 2600 mAh lay in the bins, from the Chinese comrades I wrote out such an LED (supposedly Cree XML T6 U2) with an operating voltage of 3-3.6 V, a current of 0.3-3 A (again, allegedly with a power of 10 W), a luminous flux of 1000-1155 lumens, a color temperature of 5500-6500 K and a scattering angle of 170 degrees.

Since I already had experience in converting flashlights to power from lithium batteries (and), I decided to go the same way: use a well-proven bundle: 18650 battery and TP4056 charge controller. One problem remained to be solved - which driver to use for the LED? You can’t get off with a simple current-limiting resistor - the power of the LED, though not 10 watts, as the Chinese comrades say, but still. While studying the material on “driver building for high-power LEDs”, I came across a very interesting, and as it turned out, often used AMC7135 chip. Based on this microcircuit, the Chinese have long and successfully filled up the planet with their lanterns). Schematic diagram of the power supply of a powerful LED based on AMC7135.

As you can see, power is allowed in the range of 2.7 ... 6 V, and this is a fairly wide range of power sources, including lithium batteries. The chip's job is to limit the current flowing through the LED to 350mA.
According to the chip manufacturer, a Co capacitor should be used if:

• the length of the conductor between AMC7135 and the LED is more than 3 cm;
• the length of the conductor between the LED and the power supply is more than 10 cm;
• LED and chip are not installed on the same board.

In reality, flashlight manufacturers often neglect these conditions, and exclude capacitors from the circuit. But as the experiment showed - in vain, about which a little later. Additional advantages of the AMC7135 type IC include the presence of built-in protection in the event of a break, short circuit of the LED and an operating temperature range of -40 ... 85 ° С. Detailed documentation for the AMC7135 chip is available.

Electric lamp circuit

Another important and extremely useful feature of this chip is that they can be installed in parallel to increase the current flowing through the LED. As a result, this scheme was born:

Based on it, the current flowing through the LED will be 1050 mA, which, in my opinion, is more than enough for a household flashlight, not a tactical one at all. Then proceeded to install everything in a single system. With the help of a dremel in the body of the flashlight, I removed the battery guides and contact bars:

I also removed the landing socket for the krypton lamp with a dremel and formed a platform for the LED

Since a powerful LED emits a lot of heat during operation, I decided to use a heat sink removed from the motherboard to dissipate it.

As planned, the LED, the heat sink and the head part of the lamp with the reflector will create a single whole and, being wound onto the lamp body, should not cling to anything. To do this, I cut off the edges of the heat sink, drilled holes for the wires and glued the LED to the heat sink with hot glue.