bz wrote:


Go to the library. Get an older copy of the Radio Amateur's Handbook. It
should show you how to make a tool consisting of a wire, a wooden dowel, and
a resistor, that can be used to safely discharge high voltage capacitors.

These devices were called 'crowbars' because that is what they essentially
were, a crowbar with a heavy wire that connected it to ground.


You are describing a "Shorting Stick" which is a safe way to discharge
a HV power supply to service the equipment. It was also used in
broadcast transmitters, in case the safety interlocks failed. A crowbar
is not current limited, it is a fail safe shutdown circuit, and you can
expect damage if it is triggered.


The operator would turn off the power, hang the crowbar on the high voltage
line, grounding it, and work on the equipment, secure and safe. IF someone
accidently turned on the power without removing the crowbar, it would blow
fuses.

Nowdays, a circuit that shorts the output of a power supply to ground in case
of overvoltage output of the supply is called a 'crowbar' circuit, for
reasons that should now be clear.



--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida