Oooops! Reversed supply polarity...
Posted: Fri Mar 11, 2016 12:13 pmJust curious if anyone else has done the silly thing I just did - and appeared to have gotten away with it? 
I was breadboarding a ESP8266-12 and plugged a two-pin battery header on the wrong way round. I was pressing down on the metal lid on the module at the time and soon noticed it heat up - maybe one or two seconds before I realised what I'd done then quickly pulled the battery lead.
So all the diode bodies in the mos and input clamp diodes were reverse biased and pulling a fair bit of current. I though it would be a right-off but connected it up correctly anyway, through a 1 Ohm resistor to measure the current, and it seems to be perfectly normal. I remember that TTL logic gates would sometimes work for a bit after being reverse powered but would randomly fail later on. So, get the red marker pen on it and carry on using it or bin it? What would you do?
I was breadboarding a ESP8266-12 and plugged a two-pin battery header on the wrong way round. I was pressing down on the metal lid on the module at the time and soon noticed it heat up - maybe one or two seconds before I realised what I'd done then quickly pulled the battery lead.
So all the diode bodies in the mos and input clamp diodes were reverse biased and pulling a fair bit of current. I though it would be a right-off but connected it up correctly anyway, through a 1 Ohm resistor to measure the current, and it seems to be perfectly normal. I remember that TTL logic gates would sometimes work for a bit after being reverse powered but would randomly fail later on. So, get the red marker pen on it and carry on using it or bin it? What would you do?