Hello, dear readers and self-made people!
When the light is turned off in the workshop or at home, during repair work, an ordinary directional flashlight is not very convenient, as it gives a narrow beam of light.
In this article, the author of the YouTube channel “LahisTech” will tell you how can you make a rechargeable emergency lamp based on LED COB modules (Chip-On-Board – a chip on a board). Such modules have a high density of LED crystals and high brightness.
This homemade product is easy to make and easy to repeat at home.
Materials , necessary for DIY.
– LED COB modules 12V
– LED module SMD 5050
– Protective board for Li-Ion batteries BMS 3S 12.6V 20A
– Battery 18650 Liitokala HG2
– Rocker switch KCD4, 3 positions
– Solder, wires
– Power connector
– Nickel tape for welding batteries
– Screw set
– PVC sewer pipe 50 mm, white and transparent acrylic sheets
– Super-glue 502, sandpaper
– Heat shrink tubing with glue filler, double-sided tape.
Tools used by the author.
– Mini spot welding machine
– Soldering station
– Aneng AN8008 multimeter
– Hot glue gun, hot air gun with temperature control
– Screwdriver , step drills
– Deburring knife, nippers
– Screwdriver with a set of magnetic tips
– Tape measure, marker.
So, a piece of PVC pipe with a diameter of 50 mm will serve as a body for a flashlight.
Having laid out 18650 batteries and a LED COB module along it, the author marks and cuts the workpiece to the required length.
The ends of the pipe are processed with sandpaper, then the burrs are removed with a special knife .
Now the workpiece needs to be given a rectangular section. To do this, the author warms it up with a technical hairdryer at a low temperature on one side. As soon as the plastic has softened, an aluminum corner is inserted inside, and it presses the tube against the table surface.
In order not to burn your hands, the corner is pressed with a pair of wooden blocks. So you need to align one side.
Then the flat side is pressed against the workbench with the corner, another corner is inserted into the tube.
Warming up the remaining surfaces of the tube, the author wedges the edges of the corners together. As a result, after cooling down, a rectangular box is obtained.
Cutouts for modules are marked in the upper part of the body. On the back you can choose a place for the switch.
The extra segment is removed using the dremel . The cut-out part is not thrown away – it will be useful later.
A hole for the switch is cut in the same way.
It is more convenient to drill a round hole for the power connector with a step drill – it makes it easier to find the right diameter.
The cuts are cleaned with a file and processed with a engraving machine .
Next, two plugs are cut from a white acrylic sheet. This can be done either with a hand jigsaw or a dremel.
The remaining segment is inserted into the body. In the final build, it will be installed with the edges down, not as shown here.
The author took a plastic cover as a piece of glass. Thin sheet plexiglass is also suitable.
The cut rectangular blank is U-shaped … To do this, a corner is applied to the sheet, and the glass is warmed up along it with a hairdryer of a soldering station.
The resulting glass will be inserted into the case. This is best done after installing the LED modules.
Thin holes are drilled through the walls of the case, protective glass and substrate. Parts are held together m2 screws .
The corners of the plugs are rounded off on a homemade grinder.
The battery for the flashlight consists of three 18650 batteries , included consistently. Such a circuit for switching on batteries is called 3s1p.
Having placed two batteries with the same poles in one direction, and the third – on the contrary, the cells are connected with each other with hot glue.
Also, additional insulating rings are glued to their ends.
Elements are connected in series using a nickel tape.
Mini -the machine for spot welding allows you to very quickly weld the tape to the battery contacts without overheating them.
BMS 3S protection board will control the battery charge. < br> According to the above diagram, the master solders the wires from the batteries to the pads on the board “B-“, “B2”, “B1” and “B-“.
Using a multimeter , the voltage at the terminals” B- “And” B + “. If the batteries are fully charged, it will reach 12.6V.
A pair of 12-V LED COB modules with dimensions 170 × 15mm will serve for the main light. The modules are connected to the power wires in parallel.
Both modules are fixed on the partition in the body using double-sided tape.
There will be another light source at the end of the lantern. For this, a simple LED assembly SMD 5050 is used. Two separate power wires are soldered to it.
The author isolates open contacts using a hot glue gun . < br> Both positive wires are passed through the hole for the power button, and the last module is glued into the end of the case.
After removing the protective films from the acrylic, the first plug is fixed with a second glue.
The positive wires from the LED modules are soldered to the outer terminals of the three-position rocker switch . To the central one – a common positive wire – it will go to the battery.
The terminals are insulated with heat shrink tubing and the switch is installed in place.
Both negative wires from the LEDs are combined.
Power wires are soldered to the terminals” P + “And” P- “of the BMS board. The wires from the charging connector will also be connected there.
The battery assembly with the board is insulated with a film.
It remains to solder the wires to the power connector, pass them through the hole, and solder to the terminals of the BMS board (“P +” and “P-“).
Before installing the last stub, the author checks the operation of all modules.
You can charge the flashlight from a 12-V power supply.
In this case, the modules can only work separately. You can set your own switch for each.
Here's an emergency flashlight. If desired, you can increase or decrease the number and location of COB modules , or use strips of a different size.
As a modification of the device, a buck converter for fast charging QC3.0 QC2 can be built into it. 0 , and use it as a power bank.
The production of a powerbank was described in detail in one of the articles .
I thank the author for the simple design of a small rechargeable flashlight.
Everyone good mood, good health, and interesting ideas!
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The author's video can be viewed here.
Hello, dear readers and self-made people!