PicoScope 7 Software
Available on Windows, Mac and Linux
Peak to peak voltage errors
Peak to peak voltage errors
I have recently purchased a Picoscope 2204A. I am trying to measure a ripple voltage on a DC rectifier circuit. I am measuring mV on the output of a LM7805 regulator but before even connecting to the regulated voltage my picoscope is detecting various amounts of peak to peak voltage with probes sitting on the desk. (Or even completely disconnected from picoscope) I am seeing approx. 80mV P-P when on the 5V scale, up to approx. 350mV on the 20V scale. I am trying to see if the output has less than 60mV ripple but I am above that before even starting. I have tried to attach a screenshot of this. It shows that the Measured DC average is in uV ( disconnected, probably picking up induction) and the peak to peak voltage is 176mV. I have the probes set to 1x in the software and on the physical probe. I am lost what to try next.
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Re: Peak to peak voltage errors
Remember it is a 8 bit ADC scope, so at 20V = +/- 20 = 40V total range.
40V / 256 = 0.156V = 156mv so wat you see is totally correct for a 8 bit scope.
If you want to measure ripple you need to use the scope in AC mode not in DC mode, then you can choose e.g a 5mV range of the scope.
Benno
40V / 256 = 0.156V = 156mv so wat you see is totally correct for a 8 bit scope.
If you want to measure ripple you need to use the scope in AC mode not in DC mode, then you can choose e.g a 5mV range of the scope.
Benno