Adjustable DC Power Supply 32V 10A - MPS-3210 Variable Bench Power Supply with 4-Digit Display, Compact Switching Regulated Power for Electronics Lab, DIY Projects & Device Testing - 5 Memory Presets & Encoder Control

OK I have to admit that I bought this power supply for exactly one reason: It's short. Every other hobby-class power supply I could find was tall (>6") and narrow. I had a space on my workbench that required one that was short and wide ("landscape" instead of "portrait"). I had recently bought the Matrix MPS-3010D+ linear power supply and been impressed with the quality, so I figured maybe this one would be good too. That said, I'm quite pleased with it. I currently have six bench power supplies (both linear and switching) in the house, and this is not the best, but it's also not the worst. And given the size and price it's a great deal.I originally thought I would hate that you can't just change the voltage or current without pressing a button, but actually I love that feature. It means I don't have to worry about bumping a knob and frying my circuit. Likewise, other reviewers have complained that when you press the V/I button, it doesn't remember which digit you were previously using, but I've come to think that's a good thing too for the same reason. It always starts with the least significant digit, so there's no danger of dialing in a high voltage or current by accident.- When you first power on the unit, the output is turned off, which is good for safety. The ON/OFF button toggles the output.- It remembers the last V/C setting you used.- There are 5 memories that are easy to use. Just long-press a button to store the V/C setting or short-press to retrieve it.- Long-press the OVP/OCP button to set over-voltage limit. Long-press again to set the over-current limit. While in these modes a short-press of the button turns on or off the OVP and/or OCP feature. These are absolute values that if the PS exceeds (actual output, not set output) it will go into a fault state regardless of whether you've actually manually selected a higher V/C in the main setting.- In normal operation, the display shows actual voltage and current (in constant-current mode, the voltage will be less than the set point).- When setting the voltage/current, the output changes in real time. The current display shows the SET current, not the actual current, while changing the voltage. So be careful changing the voltage if you're worried about too much current being drawn (this is actually a great time to use the OCP mode, which shuts off the output if this happens).Now, for accuracy. All measurements were made with a Siglent SDS 1104X-E scope with the PS feeding a 50 ohm dummy load (max 0.6A @ 30V) and with a cheap multimeter (DMM).Set 0.10V = ~100 mV RMS (103.5 mV DC on my DMM), Stdev 4.8 mV, ripple < 100 mV p-p, 2 mV RMS @ ~500 HzSet 1.00V = ~910 mV RMS (996 mV DC on my DMM), Stdev 48 mV, ripple < 100 mV p-p, 4 mV RMS @ ~1.8 kHzSet 5.00V = ~4.95V RMS (4.99 V DC on my DMM), Stdev 60 mV, ripple < 100 mV p-p, 5 mV RMS @ ~14 kHzSet 30.00V = ~30.15V RMS (29.9V DC on my DMM), Stdev 180 mV, ripple < 200 mV p-p, 5 mV RMS @ ~200 kHzSo in general voltage is quite accurate, especially when measured with a DC DMM, although it seems a little worse than spec when using RMS on the AC scope (note spec is usually done at full load, which I couldn't do). Ripple is within spec and isn't bad for a switching power supply, but as other people have said it might not be the best choice for RF work. Putting my spectrum analyzer next to it I don't see any obvious emissions from 10 kHz to 1 MHz and it hasn't interfered with my ham radio 2 feet away.Unlike a lot of other PS I've tested, this one never has a voltage overshoot when you turn off the output, or when you turn off the entire PS. When you turn off the output, it takes ~100 ms for the voltage to drop from 10V to zero and 75 ms to rise from zero to 10V when you turn it back on. These delays are normal for a switching power supply.All-in-all I'm quite pleased with this PS. It has a lot of features other units in its price class are missing, and it seems to be accurate and "clean" enough for most uses. I highly recommend it.