B&K Precision1550 Switching DC Power Supply with USB Charger Output 1 to 36 V, 0 to 3 A

Love this little power supply. Have had it for years, where it has been my bench buddy for trouble shooting, battery replacement and general hobby use. Did blow mine up in an instant when I hooked it up backward to a 12v 20ah lithium storage battery. Let the smoke out and it broke my heart. This PS will tolerate shorting , but apparently not having a reverse-current enema. Bought an identical replacement as I loved the features and functionality of the first one. Bright, clean, large backlit display. Compact footprint. Quiet. Cool. Adequate for me, and I am fussy, 0.5% regulation. Quality Name Brand.

Arrived rather quickly, surprised by how light the unit is. Plugged in as per the manual directions to set the current limit threshold, and it doesn't work. :/CV works beautifully, but the CC button is either disconnected or... don't know. I was not able to set the CC limit or even get the unit to switch over. Crumbs, I bought the unit specifically for the CC feature. Tried "rebooting" a couple times, no luck. I guess I just have to live with it. Otherwise I'm very happy with this unit, as it only takes up half the footprint of my old supply.Do note from a usability perspective the supply does produce some electrical noise, but its a problem inherent with switching supplies. For $140 I shouldn't complain.EDIT: The instruction manual was a bit vague. I have managed to get it to work after fiddling with it. To engage CV the current value must be set [with the leads shorted] to a value way higher than your load can consume. To engage CC the value had to be set essentially at 0.00A, which with any load will trip this threshold and force the unit into CC mode.The user manual simply states to press A for CC and V for CV. As I learned this doesn't work. With the existing unit or the new unit Amazon so graciously sent me.As a result, this review was updated to 5 stars from 3.

This is not a linear power supply. This is a switching power supply. So it has a little noise on the output. However the noise is very slight. Unit is very small and does not take up much space. Under load it does get warm but not enough to require a fan. Silly usb port on the front is useless as it is only 1/2 an amp. However this unit is very inexpensive. As other users have pointed out the only way to adjust the Amperage is by shorting the output and then setting the amps.

For the money you cannot beat this. For its variability, versatility, and voltage range it hit every requirement I needed for my office bench top usage. This would be a great addition to any aircraft small DC component tester. It fits in any small space and looks like a quality piece of equipment should look. Firm interface and easy to use. I've already used it for hours with no glitches. (I could go on and on)

Absolute junk.This thing overshoots like crazy.We purchased several of these for the lab.Set the output to 5V (CV mode).disable its outputset an o-scope to trigger on rising edge.enable its outputo-scope reliably captures the output exceeding 7V for more than 10uS.This has the potential to kill any sensitive electronics that it is powering.

I am very disappointed in this supply. It does basically work, once it is turned on and settles, but has a bad transient when the output is turned on. And it gets worse when you add capacitance across the output. For instance, if I turn it on, set the output to 5.0 Volts, then turn on the output, it overshoots to almost 6 Volts then settles back to 5 Volts. This is enough to trip overvoltage protection in some of my 5 Volt CPU boards. It took a lot of time to figure out that my problem was my "precision" bench supply. I called B&K Precision's service line, and they said: "It is a low cost supply, what do you expect?" I also had it go out of regulation during an AC power outage event, and it destroyed some components on the output due to much higher output than it was set for. It is a switching power supply, and puts out a lot of radio noise in the 1 to 15 MHz frequency range. I think there are better supplies for the price from other companies.

I'm very happy with this, it's small and quiet, exactly what I needed as I don't have a lot of desk space and use it in a living room/office environment. I read some reviews elsewhere that complained bitterly about the current-limiting feature and how it's too slow, so be aware of that if you care about that aspect.

B&K power supplies is a great product. This 3A supppy is a very good buy.