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.

Board image

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