[sdiy] Diode reverse polarity protection revisited

[Justin Owen]

Following the recent discussions about circuit protection I spent some time using the 1N4001 diode in anti-parallel (is that what it's called?) mode i.e. Anode to GND and Cathode to Positive Rail...

Running the diode in series I get a 0.3V drop and when it's reversed I get about -0.07V at the Cathode. Fine.

In anti-parallel I get no voltage drop (advantage) but when the input voltage is reversed I get a) -1V at the Cathode and b) within seconds the diode is too hot to touch.

...can someone explain the benefit to this method over running it in Series? Right now I'm not seeing it.

Thanks again,

J