How to Measure Ripple Voltage on a Switch-Mode Supply - Workbench Wednesdays
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- čas přidán 3. 07. 2024
- Measuring a switch-mode power supply (SMPS) with a DMM might show a stable voltage. But the same DC rail on an oscilloscope can show a completely different story! In this video, learn how to correctly set up an oscilloscope to characterize the noise an SMPS creates in a circuit. bit.ly/3tkVbFd
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#0:00 Welcome to Workbench Wednesdays
#0:52 What is Ripple?
#1:27 Equipment Needed
#2:20 Oscilloscope Setup#6:31 1:1 Probes
#9:43 Measurement Observations
#11:13 Give your Feedback
#SMPSripple #ripplevoltage #ripplenoise #oscilloscope #multimeter - Věda a technologie
Good video! I didn't know resistors came in TO-220 packages, but not surprised. Makes a lot of sense!
Love these videos, super helpful!
Really amazing !!!
Excellent!
Great explanation!
Nice video. Would be very interested in measuring loop stability. 👍
Good video. The electronic load is more expensive that I would have thought.
Useful video!! Interested in seeing a project for a 30 Amp 5V power supply with adjustable + or - 2V to account for losses at the load.
Always love your videos... Great content
Amaizing video! 😊
Interested in all aspects of SMPS characterization. Also interested in hobbyist level scope review. And yes, making my own SMPS as a hobbyist :)
not that I'm don't droll over things on the site or your gear. I don't have gear envy. I've worked my way up to a decent siglent I got last week. having a mouse pointer right on the scope screen is better than touch haha
As I understand power rail probes, their operation requires the power supply rail to be below a certain impedance over frequency as to not form a divider with the probe. This is not usually a problem if the power rail probe is used as a final test for ripple after the power supply impedance has been fine tuned (no peaking). So, the testing approach may be follow a set procedure of equipment and tests performed depending on how the lab is equipped.
🔌🔬
How has the power rail probe been connected? For Vout ripple measurement, the GND clip cable on the passive probe should be avoided due to the large ground loop. E.g., a spring adapter is more suitable for this kind of measurement.
When measuring voltage ripple of a power supply, its customary to put in AC mode, at 20Mhz, and put the power supply under load, but is it normal to put a 0.1uF capacitor in parallel with the output terminals? Wouldn't that serve to suppress the very AC noise we are trying to measure? The Riden video instructs us to measure Vpp ripple in this fashion, why would that be?
Probably to (somewhat?) suppress high frequency noise which is not the same as line frequency "Ripple" at 60/120 Hz, etc. Yes, we need to be clear about our objectives.
Linus tech tips was just talking about a cameras battery could you watch the bored on that so we can see what's actually happening there
Hey m8 my cb radio base station 240v mains has a very noticeable hum even with the volume down, it is not a switch mode but linear, any suggestions?
Cheers
Try add in the 12V input line one 0.1uF capacitor or another you have. Another way is add in the positive an inductor. Doesn't work. Then maybe your power supply is not regulated and need change for a better one.
Doesn't the required minimum load depend at least in part on the output voltage?
1k ohm @ 5v = 5mA 0.025w
1k ohm @ 240v = 240mA 57.6w
I could easily be wrong I'm no electrical engineer just a hobbyist
As stated in the video, it depends on what the datasheet for the converter IC says.
Inverter welding machine topic sir
Just put your multimeter to messure AC. A clean DC power source looks like 0.0v AC. If you messure anything else. You know your caps are crap and need to be replaced
No, that does not work with high-frequency switching noise. The DMM will measure 0 VAC. Follow the link in the description over to e14 for pictures I took showing my DMM's measurements.
Nowadays DMM has 10MHz bandwidth! It is good enough to get most important performance of the SMP. Check your equipment specifications on hands frist.
@@phonesmith5189 Again. I addressed this on the e14 link above. My 2 year old DMM, modern design with BLE, measures 0 VAC.
And even if your DMM could measure the noise, without an FFT, you won’t know WHAT value LC to add.
A DMM alone is not enough. Period.
@@phonesmith5189what dmm has 10Mhz bandwith in AC mode ? Expensive ones can do only 100 khz and a bit more.
I think you're a great teacher but 90 percent of people can't afford to buy from element 14 or its permutations across the world
Avoud 1:1 probes AMAS !
Hello
Purdue?
D: All this is so expensive and complicated.
I'm just a simple dumb bunny...
Yes. Designing and validating switch-mode supplies is indeed complicated.
Surface power supply can filter out all that switching noise . . . .
…
You should really do it faster when showing your vital seup on the scope to your viewers 5:20
c'mon bud, you can do it, faster faster.. hurry godammit.
If only your "feedback" wasn't almost two years late!
Good, valuable knowledge - presented at an absurd and nonsensical speed. You could do better.