Friday, October 24, 2014

Sparks = damage.

Today I discovered why short-circuiting the input side of the robust LM7812 voltage regulator will destroy it.

I've had train wrecks of series of regulators dying from a single short-circuit on the input side of things. This was most unexpected. The cause is the capacitor on the output side trying to push power backward through the regulator. It can be prevented by connecting a diode across the input and output.

Thursday, October 09, 2014

New floor

I've discovered that I need a new kind of floor in my lab. A floor that's like a carpet, so that small objects dropped on it doesn't bounce and roll away, but also a floor that's smooth and shiny, so that I can find small, dropped objects.