I want to measure how much power my PIC is using. At the output of my 3.3V regulator I put a 1 ohm resistor in series with the rest of the circuit. I was going to measure the voltage drop across that resistor to get the current and so on. With the 1 ohm resistor installed the circuit works just fine but when I put the probe of my o'scope across it it my 3.3V goes to zero. It seems as though the scope is creating a short to ground or something. Does anyone know why this happens or how to make it stop?
Electronic – Why does Oscilloscope cause short
currentoscilloscopepower
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Best Answer
The ground clip on your o-scope is actually tied to ground. it is a hard short and rather low resistance. This means that you are shorting the 3.3 rail to ground with your ground probe.
To fix this there are two options,
Let me know if this is not clear. I can add more information.