build the ultimate led lamp (li-ion) - lithium ion battery for solar street light
Emergency lights are one of the most important household necessities, mainly because we use Emergency lights in a variety of applications.
You can use it when there is a power outage, do video shooting, photography and other things while camping. . .
We have bought a lot of lead over the years.
Lead Acid solar lamp.
From incandescent to CFLs to led. .
My main application for these lights is manual and camera.
All we have is not enough to light up the subject on three issues.
Point lighting settings. Hot shoe video-
The lights are a bit expensive.
As a fan, I decided to make a cheaper version.
Cheaper but better!
Better in all aspects! .
Look at a diy led light with a 9x3 watt LEDs, made of four lithium-
Ion battery controlled by dimmer circuit.
For about 4 hours to 4 days (
Depending on the settings of the dimmer).
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I will post a video as follows
Next week, similar to my FM transmitter project video. Discrete:-3W White LED (9x)-
TIP35c pnp triode
Voltage regulator 7805-1.
5 k 1/4 w resistor-
10 k fine tuning resistor-
220 uF capacitors-
100nF capacitor (2x)-
Plastic bracket (4x)-
On/off switch :-18650 Lithium-Ion Batteries (4x)-
Rectangular plastic container
Prototype plate without welding-Perfboard (Breadboard)Tools:-Leatherman (Multitool)-Digital Multi-meter-Bench Supply-Soldering Iron-Cutting Board-
Screw the plastic holder onto the PCB.
Use a small amount of strong glue to temporarily locate the LEDs.
Now weld the led to the PCB.
This will keep the led in place.
9 v power supply for LED array.
About the heat, the led becomes very hot at 9 v (max brightness). At 6-
The 7 volt led has little heat dissipation and the PCB absorbs very little heat.
The bottom line is, never use this setting at the maximum and only adjust it at half the brightness.
By the way, half is still bright and brighter than your normal video.
We need to use a dimmer circuit to control the brightness of the LEDs.
There are two ideal circuits to use: a PWM step-down converter and a linear voltage regulator.
The buck converter is more power-efficient compared to the linear regulator, although when you shoot a video using a source controlled by the PWM buck converter, the video lens tears.
This is a schematic diagram of the circuit: when the fine-tuning capacitor is used to control the transistor base voltage, the 7805 regulator is used as a voltage reference for a large current transistor.
It's time for testing!
Try to provide a voltage of 10 v to 30 v.
The regulator should give a constant voltage output.
Try rotating the trimmer. The voltage should be from 4 v-9. 5v.
Once the dimmer circuit works, you can now install it on the same PCB that soldered the LEDs.
Now drill a hole, hot stick a button toggle switch and weld it to the dimmer circuit.
Recently, I found a store selling 18650 lithium batteries-
An ion battery of $2 each.
The rated power of each battery is 3. 7v (2000mAh).
I weld four of these series to build a 14. 8v (2000mAh)battery pack.
Be sure to weld them quickly, otherwise things can go wrong once you heat them too long.
Now weld the battery pack to the dimming circuit.
Enjoy dimmable LED lights!
: DLithium batteries require special chargers, also known as balance chargers, because they are very sensitive to over-voltage.
Upgrading the PCB as a radiator to a fiberglass PCB will increase the thermal conductivity and heat resistance.
Adding fans may solve this problem.
The lights get too hot when they are fully charged and will only last for 10 minutes if there is no fan.
Although it can run at half the power. *Use a high-
Efficiency buck converter. *Use Lithium-
Polymer * add large radiator * add fan * add ATiny85 MCU (
As a digital controller)
* Add a small LCD panel.
* Maybe gel diffuser?