# how to measure ripple voltages

K

#### ksr

Jan 1, 1970
0
I want to know how to measure ripple voltages of rectifiers,voltage regulators
and battery adapters using a digital or an analog multimeter or by any other method

J

#### Joshua K Drumeller

Jan 1, 1970
0
The best way "I think" is to view the ripple voltage is on an oscilloscope
while the power supply is under operation powering what ever electronic
device it's met to power . That is the only way to get a real idea of what
it looks like. If the voltmeter is sensitive enough you can measure it my
setting it to AC mode and remember your measuring rms and not peak. The
rectifier just takes the negative components of the voltage waveform and
makes it positive. So, on the scope you just have a bunch of positive peaks
instead of positive, negative ,positive, negative etc. Mathematically it
will look like the absolute value of sin(theta). Then using a smoothing
capacitor placed in parallel to the rectifier at the + and - sides will
smooth out the waveform to where it looks like a straight line ( or as a dc
voltage) then when you apply the load you will get a ripple (a dc component
and an ac component to your waveform). If you choose the right value of
capacitor depending on the load resistance you connect to it you can
minimize the ac or ripple component.

Josh

B

#### Brett

Jan 1, 1970
0
Joshua K Drumeller said:
The best way "I think" is to view the ripple voltage is on an oscilloscope
while the power supply is under operation powering what ever electronic
device it's met to power . That is the only way to get a real idea of what

I don't know about other oscilloscopes but mine has measurement buttons,
which when I press VOLTS automatically detects the peak to peak voltage
iirc.

J

#### Joshua K Drumeller

Jan 1, 1970
0
Yes, I would like to make a clarification here. The oscilloscope will show
peak to peak or whatever else you want it to. But the multimeter usually
will show RMS voltage unless specified.
Josh

J
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