Led flasher work as charge pump, multiply input voltage twice to get 2V pulses
Advantages compared to other designs.
- discrete components, no special QFN chip (two standard transistors, 5 resistors and 3 capacitors)
- based on charge pump design
- work indoor, no direct sunlight required !!!!
- startup current is less than 1uA, it is much lower than on commercial harvesting IC or designs
Why again BPW34 aka solar cell?
- PLASTIC, harder to break
- easy to buy, it is smallest commercially available solar cells
- there is no way to get small non Chinese solar panel
- IXYS solar bit are discontinued
- Panasonic amorton are made from glass and is not easy to buy
As you can see on video, led flashing in room light.
I created all on breadboard and about month experimentally adjust components values to get best performance.
Bill of materials with Mouser links to each component:
- 4x BPW34
- 2x Tantalum Capacitor - SMD 100uF 2.5
- 1x RED LED 3528
- 1x MMBT2222ALT1G, NPN Transistor
- 1x MMBT2907ALT1G, PNP Transistor
- 2x 0603 resistor 10M
- 2x 0603 resistor 22K
- 2x 0603 resistor 22R
- 1x 0603 capacitor 100n
OFF COURSE IT WORK WITH BIGGER COMPONENTS CASE (0805, 1206) OR TH COMPONENTS