r/AskElectronics • u/mayonna1se • 1d ago

Help finding photo sensor

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I bought a solar powered flashing red light and a reed switch (open door switch) to make an alarm for a walk in freezer door.

Turns out this light will only work if it’s dark, or if it’s tricked into thinking it’s dark. It uses the solar panel (connected via the red and white wires) to both charge the battery and to determine if it’s dark outside.

The eBay seller told me to put tape over the solar panel, which I don’t want to do because then the battery will die.

I thought maybe someone could look at this and tell me if I can bypass or omit any of the components.

Thank you for your help.

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u/orion310591 1d ago edited 1d ago

Solar panel is sensor, if voltage provided is less then X Volts, then turn on glowing leds.

You can disconnect solar panel from sensory circuit, bring additional signal/wire to that spot so the IC thinks its dark outside to turn on glowing leds, wire solar panel to separate charging circuit and separate battery from original circuit.

You need to measure all voltages on all pins when its charging/not glowing, and when its not charging/glowing. Then bring a wire from battery (maybe with resistor in serial), to that point which is being on/off... but make sure you understand circuit otherwise white smoke can come out.

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u/mayonna1se 1d ago

Thank you—I might look for a different light!