While the last circuit works well for driving a yellow or red led it runs at 2 4 v the output of the nimh battery it does not have sufficient voltage to drive a blue or white output led.
Led solar lawn lamp driver ic.
When the daytime sunlight is irradiated on the solar cell the light energy is converted into electric energy and stored in the battery and then the battery is provided for the led light emitting diode of the lawn lamp at night.
So we can add to that circuit the simple joule thief voltage booster to get a good design for a solar garden light.
The complete circuit is shown in figure 2.
This outdoor led solar garden lights project is a hobby circuit of an automatic garden light using a ldr and 6v 5w solar panel.
Solar light ics are very handy they have the dark detection circuit and the voltage multiplying led driver built into one small four pin component.
To run a led from single 1 5 v 1 2v or in particular largely depleted batteries the famous joule thief circuit using a coiled toroid is great.
Ic cl0116 lamp controller is an application specific integrated circuit asic in which solar charging and led driving sections are integrated on the chip.
It requires only an external inductor to construct a boost power supply with over 90 per cent efficiency.
You can make your own solar light or single battery led booster driver.
It offers the advantages of low power dissipation low minimum operating voltage and automatic dusk to dawn switching.
The solar lawn lamp mainly uses the energy of the solar cell to work.
The yx8018 comes in a 4 pin transistor style to 94 package and the pin.
During day time the internal rechargeable 6 volt sla battery receives charging current from the connected solar panel through polariy protection diode d9 and current limiting resistor r10.
Using the solar light ic all you need is the solar ic an inductor and the ultra bright led to make the circuit.
Inside the example i deconstructed was a single 1 25 volt 100 mah aaa nicd cell and a small pcb with the led a 220 uh inductor and a four pin voltage boosting integrated circuit marked yx8018.
Ana608 is the core component of all solar garden lights.
It boosts 0 8 2v to drive white leds or other colors with 85 90 efficency.
Solar garden light circuit.