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.
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
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
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.
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.
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.
@@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.
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.
