Tripp Lite PR-3UL DC Power Supply 3A 120V AC Input to 13.8 DC Output UL Certified

Works good.

Tripp Lite PR3/UL 3-Amp DC Power Supply 120VAC Input to 13.8VDC Output This power supply arrived with the insulator nuts for the terminals missing. In my case this was not essential as i discard them anyway but does show a lack of quality control at Tripp Lite. The unit works well and delivers a consistent DC power source at 13 volts. Works well with the electronic RFID readers i am powereing with it with negligable radio interference.

Blew a fuse after light use

Great product. Finding other uses for it aside of my hobby greenhouse.

Perfect

My PR-3UL was made in 1987, I got it at a garage sale for cheap maybe 10 years ago. The design is a simple linear one using a 2N3055 transistor mounted on a large heatsink at the back for the final output stage so it should be able to deliver the full 3A current sustained. Internally it has a fuse on the low voltage AC side. The output voltage was a little off after all these years running at 14v instead of 13.8, not bad for all this time. There is a POT that I used to adjust the voltage, but it was pretty touchy trying to adjust. For most people the voltage probably won't be too critical anyway.The design and build quality are better than the Micronta 2.5A power supply (model 22-124) that was a popular competitor from Radio Shack in the 70's and 80's.They rarely make power supplies like this anymore due to the relatively low current for the large size and weight, and the power inefficiency. The output though is cleaner vs many of the smaller switching supplies that are typically found these days. For most people though, a switching supply will be better due to it being smaller, more power efficient, and inexpensive.For the hardware hackers, this would make a good starting point for a 5A regulated 12V bench supply. Just replace the existing regulator circuit with a 78H12A and you will have a stable low noise supply. All it would take is a couple of jumper wires and placing the regulator IC where the 2N3055 is mounted.

I'm not certain if I purchased mine from this seller or not, However I have purchased one of these power supplies to turn my Mobile CB radio or side-band CB radio into a base station. I plan to use it in the event that it is the only means to communicate with others. If the internet were to go out etc. I usually run in Side-band and I don't hear many folks out there these days. But it will be great to have in an emergency.

Very regulated 13.8v output. use it for radios and projects.Over current protected.Bought mine from radio row in NYC manu moons ago and it still works.It powered my CB, breadboard projects in college, and DCC model trains.It is used now with cig lighter adapter for charging cell phones and other 12v stuff.I only paid $18.95 back then but it lasted so far.Unit is linear with transnformer and NOT switching. Very clean RFI.