Please analyze this bespoke electronic device
March 26, 2019 12:28 PM Subscribe
At my job they routinely auction off surplus tools to raise money for charity. One of the things currently up for auction is a plexiglass box with electronic components inside. What might it do? Pics and details inside.
Picture 1: Top, somewhat obscured by calipers.
Picture 2: Front panel
Additional details:
- The auction is listed as "Plexiglass electronic volt circuit. Not sure what it did" with no further elaboration. The people running auctions are unlikely to have any additional insights if asked. Maybe I could ask to see it in person, but I probably wouldn't be allowed to take extra pictures so this is all you get.
- There is an apprenticeship program here, so there's a very good chance this was built as an apprentice's assignment or an instructor's teaching aid. There may also be additional external parts that were not included.
- I currently have the top bid at $6, so any tips for figuring out what to do with it when I own it are appreciated. If I do win I can certainly provide more detailed pictures of it if desired.
Picture 1: Top, somewhat obscured by calipers.
Picture 2: Front panel
Additional details:
- The auction is listed as "Plexiglass electronic volt circuit. Not sure what it did" with no further elaboration. The people running auctions are unlikely to have any additional insights if asked. Maybe I could ask to see it in person, but I probably wouldn't be allowed to take extra pictures so this is all you get.
- There is an apprenticeship program here, so there's a very good chance this was built as an apprentice's assignment or an instructor's teaching aid. There may also be additional external parts that were not included.
- I currently have the top bid at $6, so any tips for figuring out what to do with it when I own it are appreciated. If I do win I can certainly provide more detailed pictures of it if desired.
Looks like a custom power supply.
posted by sammyo at 12:38 PM on March 26, 2019 [2 favorites]
posted by sammyo at 12:38 PM on March 26, 2019 [2 favorites]
Yep, looks like a power supply. I have one just like it at home I built in tech school from a kit thirty years ago, though without a see-through case.
They're nice things to have around the house when you're testing stuff or playing around with a breadboard.
posted by bondcliff at 12:40 PM on March 26, 2019 [1 favorite]
They're nice things to have around the house when you're testing stuff or playing around with a breadboard.
posted by bondcliff at 12:40 PM on March 26, 2019 [1 favorite]
It definitely has some design inspiration from the portable super computer Orac from Blake's 7.
posted by w0mbat at 1:24 PM on March 26, 2019 [1 favorite]
posted by w0mbat at 1:24 PM on March 26, 2019 [1 favorite]
Those cream-colored, bar-shaped might be power resistors? I wonder what they're for and why they look jumbled together. Maybe they got knocked out of place? It should go without saying but (assuming it connects to mains power) if you win the auction, be very cautious before powering it up.
posted by exogenous at 1:27 PM on March 26, 2019
posted by exogenous at 1:27 PM on March 26, 2019
If it works and if you don't have one and you need one, it's probably worth a few dollars more than $6, if you need to raise your bid.
posted by JimN2TAW at 1:45 PM on March 26, 2019 [1 favorite]
posted by JimN2TAW at 1:45 PM on March 26, 2019 [1 favorite]
Yeah, those are big power resistors. Most likely a power supply or a resistive load tester. From the size of the transformers and the big capacitor in the middle it looks like it's not meant for toy voltages.
posted by scruss at 2:50 PM on March 26, 2019
posted by scruss at 2:50 PM on March 26, 2019
I built a variable power supply that looks very similar (though with a sheetmetal case rather than plexiglass) in an engineering tech class years ago. I'm guessing the knob to the right of the voltmeter adjusts the voltage.
posted by zombiedance at 4:13 PM on March 26, 2019
posted by zombiedance at 4:13 PM on March 26, 2019
Ditto power supply. Hard to tell what's on the far right whether some outputs are variable. Meter only goes to 15v though. Probably most of the outputs are +/- 3.3,5 or 12 volts. Looks like something from EE/CE 101 lab from way back when.
posted by zengargoyle at 4:25 PM on March 26, 2019 [2 favorites]
posted by zengargoyle at 4:25 PM on March 26, 2019 [2 favorites]
You had me at plexi box with electronics. Buy it, put sound-sensitive led lights inside and have fun. Or, it's the machine that goes Ping.
posted by theora55 at 5:43 PM on March 26, 2019 [1 favorite]
posted by theora55 at 5:43 PM on March 26, 2019 [1 favorite]
Response by poster: I have use for a DC power supply but "gut it and turn it into something colorful" is definitely high on the list of possibilities.
posted by Mr.Encyclopedia at 6:04 PM on March 26, 2019 [1 favorite]
posted by Mr.Encyclopedia at 6:04 PM on March 26, 2019 [1 favorite]
You can buy very good power supplies for hobby electronics for not much money, which come with things like warranties and UL listing and fire-retardant cases. It seems a lot safer to treat the existing electronics in this thing as decorative, and hide a nice modern power supply inside (it would probably weigh less than one of those two giant transformers) if you want it to be a power supply.
posted by moonmilk at 5:06 AM on March 27, 2019
posted by moonmilk at 5:06 AM on March 27, 2019
Best answer: If it's a power supply, which looks likely - I can make the following observations:
The voltmeter indicates the output is low voltage, possibly no more than 12V.
There are two transformers, so it could be a +/- supply or two independent voltages.
Those large power resistors are probably one or more current shunts. It's possible the switches are for setting different current limits.
There is a potentiometer on the right, so some aspect of this device is variable.
The switches and the row of red sockets below them indicate this is more than just a simple power supply. It may be intended for doing some sort of device testing - e.g. "set voltage to X, plug in device, ensure it doesn't draw more than Y amps" sort of thing.
posted by HiroProtagonist at 9:37 PM on March 27, 2019
The voltmeter indicates the output is low voltage, possibly no more than 12V.
There are two transformers, so it could be a +/- supply or two independent voltages.
Those large power resistors are probably one or more current shunts. It's possible the switches are for setting different current limits.
There is a potentiometer on the right, so some aspect of this device is variable.
The switches and the row of red sockets below them indicate this is more than just a simple power supply. It may be intended for doing some sort of device testing - e.g. "set voltage to X, plug in device, ensure it doesn't draw more than Y amps" sort of thing.
posted by HiroProtagonist at 9:37 PM on March 27, 2019
Response by poster: FYI I got outbid and, primarily thanks to the responses here, did not pursue it further. It ended up selling for somewhere in the $30 range. Godspeed to whoever is brave enough to plug it in.
posted by Mr.Encyclopedia at 1:37 PM on April 2, 2019 [1 favorite]
posted by Mr.Encyclopedia at 1:37 PM on April 2, 2019 [1 favorite]
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posted by ptm at 12:33 PM on March 26, 2019 [3 favorites]