Unsure how to connect scope probes to DUT with no ground points.

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Thread Starter


Joined Jan 12, 2012
Hi I was stumped for a moment. Please refer to the circuit diagram:- AC Power Light Dimmer/Motor Controller
This is my first time, not knowing how to test this circuit with my oscilloscope with no ground point.
Because this circuit has no ground point. Please advise how I can perform it correctly.
The circuit is working but I wanted to learn more about the working of this circuit.
Thanks in advance.

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Joined Oct 2, 2009
Testing live AC mains circuitry requires expert knowledge. This is not a task for an amateur for safety reasons. Besides it violates the Terms of Service of this forum.

If a dimmer circuit fails, quite often just replacing the triac will rectify the problem.
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