Measuring Ripple

[walters]

How do i measure Ripple? with a oscilloscope and multi meter

What are some bad ripple waveform look like?

How do i do Ripple waveform checking? with a oscilloscope

Using Different LOAD resistances on the output of the power supply
would change the Ripple waveform what are some signs of the
ripple waveform looking good vs looking bad?

 

[walters]

How do i know if a circuit is drawing to much Current?

How do i measure the current draw ?

how would i know if its drawing to much current?

 

[walters]

How do i know if my power supply is outputing a Balanced waveform?

What if my power supply is outputing a Unbalanced waveform what
does a unbalanced waveform look like ?

 

[stevez]

Regarding ripple - it's my understanding that this would be the variation of output voltage from a power supply that is at some integral multiple of the AC frequency used to power the supply. This is AC and on some meters you might be able to measure it by dialing in the AC range. You might also use a capacitor to couple a meter since capacitors should only conduct the AC portion. The calibrated scale of a scope is yet another way just make sure you use AC coupling so it ignores the DC - even if you don't do that you could see the difference between the low point and high point.

Good or bad ripple is quite dependent on the needs of the load. I'd say that the appearance of the waveform is meaningless without some understanding of the needs of the load. Many 13.8 vdc power supplies claim to have no more than 100 mv rms ripple - that seems to be a pretty common spec.

Do a little reading on AC to DC power supplies - capacitor filters, ripple rejection, etc.

 

[David Bridgen]

How do i know if my power supply is outputing a Balanced waveform?

What if my power supply is outputing a Unbalanced waveform what
does a unbalanced waveform look like ?

Your power supply shouldn't be "outputing" any waveform. Its output should be d.c.
The ripple on a decent supply shouldn't exceed 10mV or so whether it is loaded or not.

 

[Dean Huster]

The easiest way to measure ripple is to connect an oscilloscope, AC-coupled, to the supply output. Start with the attenuator set for a high volts/div setting before connecting the probe to the circuit and then lower the setting until you can observe a measureable waveform. As David mentioned, the ripple on a good, modern, electronically-regulated supply will be in the low millivolt range. The scope will be measuring peak-to-peak voltage. Ripple may be spec'ed as rms units or p-p units. Tektronix tended to use p-p units -- go figure!

Dean

 

[walters]

Thanks alot for all your guys help this is helping me and other understand more when we read this thread

 

[walters]

How do i component check a rectifier?

What are some basic rectifier tests i can do ?
to see if its working right with different loads?

Line regulation and load regulation test?