Coffee

189

02:17:00

Schematic from a coffee maker i tore down, an mcu has been replaced by a switch on th top. There's an AC to 5v transformer and its ground is lifted from the rectifier negative so much it is used to power a relay. The current across the relay is so low a transistor shorting its coil pins is used to shut it down. Its pretty odd i think. 

published 5 years ago

edmeme

4 years ago

In retrospect, the transistor shorting the coil might be a failsafe mechanism

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