Junk-drawer Benchtop Power Supply (3D printed enclosure) - Page 1
Forum section: electronics / projects

author: flimshaw
author_rank: Contributor
timestamp: January 19, 2016, 03:38:47 am
content: It's not Shakespeare or anything, but I figured I'd share my first home-made bench-top power supply with you, the internet. I was inspired by that great 4-part power supply design series on the YouTube channel (https://youtu.be/CIGjActDeoM?list=PLBF35875F73B5C9B5). Mine is just what I had lying around to start getting some work done. I'd like to add constant current and maybe a full-wave voltage source at some point, and just generally clean it up. Orrrr maybe just buy one. But learned a lot knocking this one together.It's mostly some junk drawer parts, including:1. a random 12-15V AC transformer from somewhere2. a full wave rectifier3. a 7-seg digital voltmeter from Adafruit4. a precision 3-turn 2k pot from allelectronics5. an LD1085V50 from god knows where6. a safely fused 3-prong power adapter socket from allelectronics7. a bi-directional red/green LED attached across AC 12V w/ limiting resistor (aka an orange LED that looks like christmas if you shake your head)8. a toggle switch from somewhereI 3D printed the enclosure on my Powerspec Rep2 clone in natural PLA, so the lights inside are visible but diffused. The model is this great split-body enclosure set from Thingiverse:http://www.thingiverse.com/thing:1058336. It printed out really nicely, kind of susceptible to warping, but really sturdy once it's together. Highly recommended.Anybody have any tips on building an adjustable split power supply from a center tapped mains rectifier? Found a few designs around but if anybody on here's got a favorite, would love to get some advice.Feedback is welcome, I have much to learn.Thanks all,-Charlie

author: Mechatrommer
author_rank: Super Contributor
timestamp: January 19, 2016, 06:04:04 am
content: Quote from: flimshaw on January 19, 2016, 03:38:47 amif your transformer get hot during operation, your PLA will sag happily... ymmv.

author: Unknown
author_rank: Unknown
timestamp: January 19, 2016, 03:37:14 pm
content: Quote from: Mechatrommer on January 19, 2016, 06:04:04 amLooks good, but I will second what Mechatrommer said. PLA gets soft at quite low temperatures, ABS would be better if your printer supports it.

author: bitseeker
author_rank: Super Contributor
timestamp: January 19, 2016, 11:14:01 pm
content: Nice job. I like the look of the diffused LED.Do you binding posts go all the way through the case? If so, are those wires coming through the front panel necessary?

author: macboy
author_rank: Super Contributor
timestamp: January 20, 2016, 02:42:36 pm
content: Nice to see junk-drawer parts put to use. 3D printing is really interesting, but I'm not ready to get into it yet. When I can go to Best Buy and pick up a simple, cheap 3D printer for a hundred bucks, then I'll be ready. I am old enough to be no longer interested in leading edge stuff, but when younger I bought Epson's first larg-ish format six ink color photo printer for around $1000 (Stylus Photo EX, ca 1998). That was just putting color ink on paper. I think I could get into 3D for less today.I was wondering, why did you bring the output wires to the outside of the case then into the binding posts? Why not attach them to the binding post mounting studs on the inside?

author: jbix
author_rank: Newbie
timestamp: January 20, 2016, 06:12:29 pm
content: I like. Junk-drawer projects rock. A very nice, artsy picture, btw. Hopefully you had fun and got to learn a bit along the way!

author: KL27x
author_rank: Super Contributor
timestamp: January 20, 2016, 08:42:18 pm
content: You're not fooling me. The angle of the photo indicates this is just a face plate!3D printing has so far failed to impress me as anything but an exercise in doing 3D CAD. For that, I will buy it when it's cheap enough.