Comment on SMD Component Identification
jeinzi@discuss.tchncs.de 5 days agoThere’s no way U1 is charging the battery. How would it? If the connection labeled USB is the power source, it’s only connection to U1 is through a 100k resistor and a reverse biased diode. Also, charging AA batteries? Sure, you could plug in some NiMH cells, but then the device would need to have explicit instructions telling you that this is indeed a charger and to only ever insert rechargable AA battery cells.
bruce965@lemmy.ml 5 days ago
Fair point. There were no such instructions.
I tried desoldering U1, disconnecting the piezo, and powering it with 3V from the batteries side. It blinks rhythmically, so I assume the MCU (or ASIC) is fine. But if I connect the piezo, power consumption drops to < 1mA and nothing else happens. So yeah, that component’s purpose is probably not to charge the batteries.
I will try to read the markings again with a magnifying glass later today. Unless you or someone else have better suggestions.