Day 61, Benchtop Power Supply
Back on day fifty, I mentioned when I was talking about the hot wire cutter I tinkered together I mentioned that I powered it with a benchtop power supply, in particular an Eventek KPS305D that I bought years ago for electronics tinkering. I thought that perhaps today it should get some recognition on its own. It's an adjustable current limited supply, which can output from zero to thirty volts and up to five amps. I have used it for a bunch of different projects:
- Powering electronics projects, which is what I originally got it for. While most of my microcontroller projects are powered by 5V or 3.3V (where a fixed output supply is probably a good idea) occasionally I've worked on ham radio projects where 12V or higher might be useful.
- Powering my before-mentioned hot wire cutter. The ability to limit voltage and current makes adjusting temperature pretty straightforward.
- Removing rust on old parts via electrolysis (a topic which perhaps I'll mention in a future installement).
- Recharging batteries.
It's the last one that I've dusted it off for today. I have an old UPS (made by APC, a Back-UPS Pro) that I believe I got from the free table at work. I was wondering if it still worked, so I plugged it in and hit the "Test" button, and after a minute or so, it began to flash the red light indicating that I should replace the battery. Hmmph. I pulled the battery out, and it had a label on it indicating that I had tested it back in 2023, and that it had a voltage of 13.1 volts. Today, it showed a no-load voltage of about 12.1 volts. So, I decided to hook it up to the power supply give it 13.8 volts for a few hours and see whether that brings it back to life.
Addendum: nope. It didn't. After a few hours of charging it still held a voltage of only a little over 9 volts. Guess that battery will be sent to the recycler.
Frankly, I could use a much better benchtop supply. One thing that's kind of annoying is that it's purely analog. When you plug it in, it starts supplying voltage. I'd like to be able to set voltage and current limits, and then toggle on the output. But for the modest uses I have, it's adequate and until I have more demanding uses, I guess I'll keep using it.
Happy Tuesday!