MATRIX Regulated Linear DC Power Supply 30V 10A, 100 mV 10 mA Bench Power Supply Variable with Voltage/Current Pre-Setting, Output Button, MPS-3010D+

I took a bit of a risk buying this power supply with no reviews available, but I figured with free returns what could go wrong? So here is your complete, unbiased review. First of all, the unit is heavy and feels solid, with a metal case and a sturdy carrying handle. There are LOTS of ventilation holes on all three sides, and an opening for the fan in the back. When you first power on the unit, the fan does a quick self test but then turns off again - this is very nice! There is no constant fan noise unless actually needed. When first turned on, the output is off so no voltage is applied to the output terminals. In this state you can set both the desired voltage and maximum current using the two pairs of coarse and fine adjustment knobs. To turn on the output, you just hit the output on/off toggle. Once the output is on, the volt and amp displays show the actual output. You can adjust the voltage while the output is on, and you can also adjust the maximum current but you can't actually see what you're doing since the display is showing the flowing amps not the maximum amps. This is all as I would expect.To test accuracy I used a cheap multimeter and a nicer oscilloscope, which generally agree with each other within ~0.01V. Because the knobs are analog and the display is digital, there is a minimum and maximum knob setting that shows the same display value. I looked at the calibration at these minimum and maximum positions for several voltages (photos 1-3):1.0V:Min setting yields 1.04VMax setting yields 1.13V (~10% off)Output standard deviation <1 mV, actual peak-to-peak <10 mV10.0V:Min setting yields 10.01VMax setting yields 10.11V (~1% off)Output standard deviation <1 mV, actual peak-to-peak <10 mV30.0V:Min setting yields 29.8V (~0.7% off)Max setting yields 29.9VOutput standard deviation <1 mV, actual peak-to-peak <10 mVIn general, the output was always within ~0.1V of the set point. Ripple was negligible and constant across all voltage ranges, with no load and with a small 50 ohm load (0.6 A @ 30V).I also tested current flow, but I'm not sure how much I trust my cheap multimeter. Here's what I measured (photos 4-6):0.10A yields 0.08A (20%)1.00A yields 0.97A (3%)5.00A yields 4.93A (1.4%)I didn't try 10A because I didn't want to burn out my multimeter.When you turn on the output at 10V, there is a transient peak of 10.8V. When you turn off the output at 10V, there is a transient peak of 10.6V.If the output is on when you turn off the main power, it takes 77 ms for the output to start to decay. There is also a 20 us transient of up to 20V (photo 7). This is a little scary, and I would suggest disconnecting your circuit, or turning off the output, before powering down the whole unit. If the output is off when you turn off the main power, there is a 170 us transient of up to 10V. At least this one doesn't peak above the set point. These kinds of transients seem common in modern power supplies, but they're still a little annoying.All in all, for the price (especially for a linear PS), I think this is a very nice unit. It has all the features I've been looking for and no real downsides as long as you're careful with the transients.

Using it to power a 12V - 10 Amp heater. The voltage and current settings drifted 0.03 V and 0.05 ampsas it warmed up and has been stable ever since. The only additional info I have is that the supply boots up inthe standby - voltage / current setting mode, you have to press the Output button every time to get voltageoutput. This is not a problem for a bench supply, but could be a problem in a test setup that's automated.

Update Jan 22, 2021: I was contacted by Matrix and asked to evaluate another unit and update my review. I received the new power supply today. It did not work. It powers on and the displays react to turning the knobs. When I press the Output button the Voltage drops to half of the set value and the amperage goes to 0. I opened it up and found a loose connector to the interface board that was supposed to be glued into place had worked loose. It still did not work until I found the 220VAC/110VAC switch was set to 220VAC. When I set it correctly it started operating. I could not get it to output 10A it kept shutting off output when it got above 9.57A at 14.6V. It would shut off at 8A at 5.7V. It did operate from 5.6-30.0V as indicated, but not near 10A. It still doesn't work as well as the first one. It still goes into "OTP" and shuts off at 14.7V 9.0A and just shuts off output at 14.7V 8.5A. So still not working as described. Kudos for trying Matrix, but still a failure.Original Jan 2021:I bought this to charge LiFePO4 batteries and cells at 10A. I took a chance based on the one review. It mostly works. The output function where the current and voltage can be set ahead is a very nice feature (also why I took a chance on it). I charged my EcoFlow Delta 1400 at 30V set at 9.99A for over 8 hours. The EcoFlow settled at about 8A 240W charging rate. Changing the voltage on power supply didn't change the charge rate. The EcoFlow Delta is rated at 400W charging. The MPS-3010D+ power supply was hot to the touch when charging stopped and it heated the room substantially.I went to charge my 24V 50Ahr LiFePO4 battery with it at 9.99A and 29.2V. First when I depressed the "Output" button nothing would happen. There are 2 distinct clicks when it engages the load. I then disconnected the battery then activated the output and started charging the battery when I connected it. Within a few minutes it shut off (the relays make very distinctive clicks) and "otp" showed in the Volt display. It was not hot that I could feel, but I did not open it up to find out. I tried this 3 more times and it does the same after a few minutes each time. The included manual which has a different model number than what I received is silent on the "otp" display.I contacted Amazon Product support which was no help. She recommended I message the Seller (that system is even worse) after she attempted to contact the seller via phone. I received a response from the seller after about 12 hours. Seller was attentive (3 responses) and suggested adding a diode to prevent reverse polarity from the battery, and using it at 8.0A instead of 10A. I then tested it at 8.0A, 8.5A, 9.0A, and 9.5A at 29.2V all at CC. The "otp" kicked in at all above 8.5A. Not acceptable to list at 10A and it be usable at 85% rating. Typical Chinese crap rate it too high then they say "we really didn't mean that" rhetoric. It is going back. The manuals clearly states that using it near its limits will shorten its life. If its usable limit is 85% listed then it will have a very short life. I have a 35 year old HP linear power supply (0-50V, 500mA) that still works.Overall, if you need a 30V 8.5A power supply instead of a 10A power supply this may work for you. I do not recommend it. I have no patience with products rated over usable specifications.

Long story but I bought an MTH o scale locomotive then to find out i need a way to control it if I want to implement the DCC features. So I buy the NCE power cab and I'm off running the train but the system overloads if it exceeds ~1.5A and it does when climbing a grade pulling cars and smoke on. So I then buy the NCE Smart Booster SB5 which provides 5A. This will run 2-3 trains (o scale) no problem. Wall wart PS that came with SB5 meh so I bought this. Old school linear PS is ideal for this application. It will likely work in other scenarios quite well.When first powering on it displays the V and A limit settings which are adjusted using the relevant knobs. No power is applied to the output initially until pressing the output button which enables power out. The meters at this point monitor the actual output. The amp meter is useful in my application. In my experience any 'spiking' when engaging output is not an issue.