HANMATEK HM305 DC Power Supply Variable, 0-30V/0-5A Adjustable Bench Power Supply with 4-Digit LED Display, Display Power, Lock Function(Button), Protective Function, One Key Switch Control

This power supply did all I needed it to. External monitoring of voltage stability, ripple and current were all very acceptable for a 100$ bench supply... Well, a SMPS at least.Unfortunately, within 3 months, the unit failed. No dead, no back EMF pumped into it, etc. I was using it to drive 1-20w laser diodes, relying on its extremely decent CC and voltage clamping at the set current draw. Never drew more than 50w from the damn thing. It failed, taking out a 7w 450nm diode in the process, and popped its fuse while doing so. On attempting to replace the fuse, it immediately draws nearly 500w from the wall (indicating some form of dead short inside) and pops the fuse. No service is available after the first month, so returns aren't possible.

This is a basic DC Power supply. I like the control buttons that let you select precisely the voltage and amperage and after a second or two they lock so you need to push them again to change the values. Many other similar brands offers analog potentiometers that are often finicky to use. This unit is housed in a metal casing and it feels sturdy. I tested the unit for accuracy with my digital multimeter and they concord within the tolerances. There's a third readout that gives the wattage used. An handy push ON push OFF illuminated button at the front supplement the master ON/OFF button located at the rear of the unit; very useful if you need to safely change the voltage or amp values without risks. There are some minor annoyances: the alligator leads are OK but not great. Unfortunately, when you power the ON the unit, the front power button is ON by default; it should be OFF in my opinion for better safety. Of course, this is a switching PSU, not as good as a linear PSU but for basic usage you cannot beat the price and value of this unit.

Great little power supply for the hobbyist. I purchased the 10A model since it was just a little bit more money and will give me some flexibility for future projects I might work on.Nice compact size and fits into any corner of your workbench. I love that the three different readings are different colours which makes it super easy to see at a glance what is going on. Controls are good and take only a few seconds to figure out. I also really like that there is a switch for turning on the output so that you can adjust the settings before actually sending power out to the device you are working on.Now you can't compare this to other "professional" units that cost many times more than this. This unit is made for a hobbyist that will use it occasionally. If you need something very precise and made to work all day, every day, you need to spend a lot more money. But for most people, this will be a great unit for their workbench.I use this for powering a variety of older electronics that no longer have their original power supplies, as well as for building small projects that need specific voltages. Very happy with my purchase. This unit has done a great job powering 99.9% of my projects and I would recommend it for anyone looking for a basic, hobbyists power supply.

Great value for a very useful power supply. The current and voltage adjustments are very easy to use since you can selected which digit to adjust by pressing in the adjustment dial. After selecting the digit, the notched adjustment dial would increase or decrease the selected digit by one for every click of the dial. This made fine adjustments very easy.As others have mentioned, the output defaults to the on state when the power supply is turned on. It should default to the off state. So, make sure the output terminals are disconnected before turning the power on. Once powered on, select the output to the off state, set the voltage and current to the desired levels and connect the output to whatever it is that you're powering, then turn on the output.As others have also mentioned, the test leads that comes with the power supply are pretty useless. I found the problem is with the spring contacts on the connectors that plug into the output terminals. They do not make proper contact with the plug that they are wrapped around. I jammed a short length of copper wire under the spring and that seems to solve the problem. The better solution is to buy better leads.The power supply has already paid for itself as I was able to revive a lithium ion battery pack by slow charging the discharged cells. This was possible because I was able to limit the current on the power supply.