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Old 05-02-2016, 11:32 AM
dieseljeep dieseljeep is offline
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Quote:
Originally Posted by wa2ise View Post

This is your typical emission tube tester. It's a "hot chassis" design. And you could "find" the powerline via the top cap connection, depending on the selector switch setting. Oh, another setting could give you a path to the other side of the line via a 1.8K resistor and the sensitivity control. Not exactly that safe, but if we put a polarized plug on the tester we can avoid the "harder" connection first described. If we connect the cord's hot wire to the power switch.

Don't use a 3 pin plug to ground the metal chassis of the tester. Same reason they don't ground the metal cases of toasters, as someone trying to remove a stuck piece of bread would be holding that case and touching the heating element with a knife.
All newer toasters have a double-pole switch to isolate the elements, per U/L.
Those Accurate Instrument test instruments, were the ones advertised on the back of magazines like Popular Electronics and others.
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