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Unread 08-11-2016, 08:55
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Re: LED bulb question

Quote:
Originally Posted by Ether View Post
The resistance of the bulb changes substantially as the filament gets white hot.

I don't have a DVM that uses 120 volts to measure resistance.

.
Quote:
Originally Posted by Ether View Post
... and the inexpensive DVMs I have access to don't support measuring AC current with 120V applied.


Is your DVM sensitive enough to measure the resistance of a power cord? If so, you could measure the resistance (without 120V) and the voltage drop (with 120V through it and the lamp, before the power cord heats notably) to calculate the current flow. It will not tell you anything about the relative phase of current and voltage through the lamp, however.
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