[SOC] Re: [autotrax] OT _ TO-220 proper installation?

[Paul Bartlett]

>
> Apply common sense and run through all the scenarios
> in your mind and ask yourself, "What are the risks of
> having some exposed voltage?"
>

I concur completely, Tom.

An old colleague of mine was working on a piece of kit in a 19" rack. It was
pulled put for servicing and powered up. It was a 3 kV PSU for some kind of
scientific equipment; I forget what.

Anyway, due to his carelessness the kit started falling out of the rack and
he grabbed it by the heatsink at the back to gain a grip. He woke up 3 hours
later in hospital. The heatsink was carrying the full output voltage
(thankfully only a few milliamps available).

In this case it was a serious manufacturing rather than design flaw.

Personally, when fault finding equipment with high potentials involved I use
the technique taught to me by an old WW2 radar technician. Wear rubber soled
footwear and always keep one hand in your pocket (preferably your left).
Avoids cross body shocks that can affect your heart.

Paul :-|