B&K 1550 based on same design as Tenma 72-8345 and Manson NSP-3630

[dh]

Sorry if this is traveled ground, but I just picked up a B&K Precision 1550 cheap lab power supply. The Amazon reviews are hit or miss, but I figured it was worth the money to get a 'travel size' supply.

I was surprised that there are no teardowns that I could find, and not much more than a review or two.

Here's what I found when I opened mine up: virtually the same thing that Mike and Phil found.

http://jumperone.com/2012/12/manson-nsp-3630-power-supply-teardown/

The only difference I saw is that they seem to have updated the power supply PCB to get rid of the resistor on the bottom, and the UI was changed significantly, although the circuit boards behind it look very similar.

I saw a couple of things inside that bothered me:
1) When trying to disassemble things, the wires chaffed pretty badly on the rough-edged chassis. Not a huge deal if you don't take it apart.
2) It is possible to disconnect the GROUND WIRE for the POWER CORD with just a screwdriver from the outside. A lot of times you'll see a grounding screw on the outside of equipment... this is usually(right?) an extra screw that is available to bond the chassis to an external ground.

In the case of the B&K 1550, it holds down a ring-lug that grounds the chassis inside, held on by a nut. If you gave it to an enterprising fool, it is possible to loosen that and disconnect the chassis from ground, while leaving a nut to roll around inside. Yikes.

Overall if you know what you're doing, not such a big deal, but I'm not sure this unit would pass UL like that!

Keywords: B&K Precision 1550, BK Precision 1550, switching power supply, lab power supply