On 4/4/2010 5:16 PM HeyBub spake thus:

David Nebenzahl wrote:

On 4/4/2010 3:15 PM Steve Barker spake thus:

Dave wrote:

Wow. So, bottom line is, an analog meter is the only thing you can
really trust?

I believe there was a trick to make a digital meter NOT show phantom
voltage, but i don't remember what it is.

Simple: put a large-ish resistance (say, 50-100K ohms) across the
leads to reduce the input impedance. This will shunt any phantom
(induced) voltages away from the meter.

A light bulb is better else you may forever have imprinted on your memory
the smell of a burning resistor.

You're not going to get a burning resistor, Bub.

Do the math. Using Ohm's law, let's say we gots a 100K resistor. If the
voltage is 120, the current through it is 1.2 mA, and the power being
dissipated is a little more than 1/8 watt. So use a 1/4 watt resistor if
you're paranoid. Maybe a 1/2 watt one for up to 240 volt measurements.


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