Adjustable DC Power Supply (0-30 V 0-10 A) with Output Enable/Disable Button HANMATEK HM310 Mini Variable Switching Digital Bench Power Supply with USB Charging

Why did you pick this product vs others?:This unit is amazing. I use it for my electronic projects and it allows me to adjust both voltage and apmerage. It also shows amperage draw. It can go from 1.5 volts to power LEDs and up to 32 volts if needed, With micro adjustments for both amps and volts to get the exact current and power needed.

Just what I needed for hobby projects. Product works well, looks good for price.

Worth the price I use this for bench testing anything from a car stereo to LED lighting HID headlights blower motors for the HVAC on a car who wants to install an electrical item in a tough spot without testing it accidents happen sometimes a brand new or remanufactured item may not function It’s nice to know that before I install it. It does put out enough power. I use it quite frequently. I didn’t take any pictures. It doesn’t look anything different than the pictures in the listing

I normally read the negative reviews before buying something in order to see what issues others have experienced with it. So I did some extensive testing after receiving this power supply and evaluated some of the concerns that I read.The bottom line is that for the price this is actually a pretty decent power supply, so I think I'll keep it. It's light and compact and the ergonomics are good. I like the simplicity, the output on/off button (separate from the line power switch) and having the USB port at the bottom near the output terminals rather than in the middle of the control panel. The power switch being on the rear panel is a little awkward, as is the voltage and current adjustment method, but that's not a dealbreaker.The line leakage current to ground is 35 uA (157 uA with an open neutral), and 38 uA at the output terminals, meaning it could be safe to use in a medical environment (though I'm not sure why you would) and shouldn't pose any OSHA problems.There is a mention of voltage on the output terminals when the output is switched off. At various loads between 10 and 10K ohms, the worst cases I measured were -.117 V, -240 uA, and max power at the terminals of 8.3 uW. Basically these numbers are negligible and usually should not be a concern.As for the output I found a maximum voltage error of 20 mV and max current error of 3 mA.An issue I found is that the output is switched on at power up, where ideally it should be off. Also, when the line is switched on there's a 1.6 sec delay before the output comes up, and halfway through this period there is a spike of 2 to 3 volts. These usually shouldn't be an issue, since it's good practice not to connect your load to the output terminals until after turning on the main power. Incidentally, upon power up, it retains the last voltage and current that was set.Of course this unit is just one sample so your mileage may vary, and only time will tell how well it holds up. Oh, and be sure to download the pdf of the op manual from this page, you'll need a microscope to read the paper one that comes in the box.

Pros:The display is absolutely stunning! There is a screen protector film installed so you'll want to remove that to really see the screen at it's best. Overall it is a very elegant, clean, and modern looking unit.The output button is great. You can cut off the output while you're making adjustments if you want. But if you want to make adjustments while outputting you can still do that, too.It mentions these two features in the manual, but the font is pretty small: If you hold down the voltage knob for a few seconds it will lock the starting state of the output button each time you turn the unit on, so you can default it to having the output off or on at startup. If you hold down the current knob for a few seconds, you can lock the unit to prevent accidental changes to the values. The output button can still be turned on/off while the unit is locked.The displayed voltage seems to be fairly accurate. Testing the open circuit voltage output with my Fluke 177 DMM, the supply was always within 5mV. I haven't tested the accuracy of the current, yet.The adjustment knob lets you change the value of any digit but if you keep scrolling it will increase or decrease the surrounding numbers so you don't have to keep moving between digits. For example, if your voltage is currently set at 3.3v and you want to bump it up to 5.0v, you can either adjust the whole number and the tenths place individually, or you can just stay on the tenths place and it will advance the whole number along with it. (Once you hit 3.9v and advance one more click it will go to 4.0v, not reset to 3.0v) Having the flexibility to change values in either way makes things really nice.This isn't unique to this particular brand/model but like most other switching type supplies, it is very compact and light weight.It is totally silent. It does have a fan and I think it will turn on under higher load requirements but so far I haven't had it turn on.The power reading is awesome if, like me, you often want to see the power draw of a particular circuit.Cons:The power button has to be pressed a little bit farther in than you might naturally think in order to stay latched. The first couple times I powered it on I found myself pressing it in far enough for the display to light up but as soon as I let go the button depressed and it turned off. Not a big deal at all just something to note.The case is plastic. If it just sits on your bench it probably doesn't matter. If it's something that you move around a lot it might not hold up as well as a metal case. The fit and finish seems to be pretty good but it's not built like a tank by any means.Once you press down the voltage or current knobs to make adjustments, you only have two seconds before it exits back into normal operation unless you're moving the knob, so you have adjust quickly.It takes a fraction of a second to limit current. I hooked up a simple LED and set it to limit to 10mA. When I turned on the output the LED was extra bright for just a very brief moment. From what I can tell it's not an issue as it's such a short transient but perhaps it could be something of concern for more sensitive circuits? As long as you're also limiting your voltage to an appropriate level, I don't see it being a problem.