For the price of a dinner for three at Wendy's!
I have had Astron and other power supplies in the past but recently wanted one that would cost less that 40 dollars and have good specs. Doing some research on the net I found the SUPERNIGHT 12 volt 30 amp 360 watt supply for 21.00 dollars shipped. Besides the basic specs it comes with short circuit protection, over-voltage and has an adjustable output up to 14 volts DC. It also has a fan that comes on automatically if the temp reaches 45 degree Celsius. The supply comes only with a terminal block and no AC jack.

I found an old 3-prong power cord lying around and wired up and saw it had a green LED to show it was working and putting at 12 volts. Next I needed an enclosure. Harbor Freight sells sturdy plastic ammo boxes complete with a carry handle and snap locks. This box would give me plenty of room to work with and allow air to circulate with a couple of drilled pinholes in the right places. Lastly some binding posts (red and black) and a digital 0-30 volt DC blue LED meter from All Electronics were ordered. I could have saved 8.00 and or fudged something from another junk piece of gear but I did not have anything to work with and I wanted it to look nice. So at this point my total in parts and PS is 32.00.

I drilled a hole to slip the power cord through, then tied a knot on the inside of the box to keep it from coming out or pulling on the wires. Then drilled holes for the binding posts and tightened them down with the supplied hardware. The meter will be added later when I decide placement. Once the power supply was inside I made the adjustment to the output voltage and was pleasantly surprised that it would go to 14.1 volts and by using the tiny potentiometer on the board, turned this back to 13.8 volts.
I am sure a lot of hams could have found suitable containers (bread box, Tupperware etc, and have the same parts I bought lying around and saved 10.00 bringing the total back down to 20.49.
You could also get elaborate with a on/off switch, which I still may add, maybe a lighted 12 volt one from your junk drawer and a fuse holder. Here are photos of the final project results. Total cost 37.58


Thanks for reading!
KJ4DGE
| KJ4DGE | 2021-07-26 | |
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| Re: A 12-Volt 30 Amp Power Supply | ||
| No voltage sage at all running two rigs, a Xiegu G90 and a Anytone UV778. The digital voltage meter I decided to use shows constant 13.8 volts. Reply to a comment by : N8RKD on 2020-04-11 Might be a tempting project. What kind of voltage sag are you seeing with a heavy load? I'm thinking a 100W CW transmitter | ||
| VE3WGO | 2020-07-27 | |
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| A 12-Volt 30 Amp Power Supply | ||
| another eham article talks about RF emissions of a cheap switcher.... might want to be careful about using these near an HF radio or HF antenna. Also, make sure it has some crowbar protection in case the unit fails to overvolt, like maybe 18 volts, which would of course kill most radios. | ||
| NC0L | 2020-05-27 | |
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| A 12-Volt 30 Amp Power Supply | ||
| Boy, I sure ended up with considerable RFI no matter where the unit was plugged in at the house. | ||
| K2WH | 2020-05-18 | |
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| A 12-Volt 30 Amp Power Supply | ||
| I found those cheap supplies scream with all kinds of RF hash, that's why they are so cheap. | ||
| KD2HU | 2020-04-22 | |
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| A 12-Volt 30 Amp Power Supply | ||
| Thanks for the review. I ordered one yesterday - $18.95 at Amazon. Now all I need is another $1k for a transceiver. Baby steps, right? | ||
| KO4AMB | 2020-04-20 | |
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| A 12-Volt 30 Amp Power Supply | ||
| Found them on Amazon. $20.96 https://www.amazon.com/SUPERNIGHT-Universal-Regulated-Switching-Transceiver/dp/B01IHNE746 A buck less here: $19.99 https://supernight.cc/products/lc-003 Have 2 on order via Amazon, as their easier to return from them. And Thanks ! | ||
| N8RKD | 2020-04-11 | |
|---|---|---|
| A 12-Volt 30 Amp Power Supply | ||
| Might be a tempting project. What kind of voltage sag are you seeing with a heavy load? I'm thinking a 100W CW transmitter | ||
| KJ4DGE | 2020-04-10 | |
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| Re: A 12-Volt 30 Amp Power Supply | ||
| I have an RFI meter and my cable box and fridge put out loads more RFI, I guess you either get a good one or a crappy one. Reply to a comment by : K4FMH on 2020-04-09 Hi, Thanks for posting your project, Greg. Have you checked on the RFI? Just curious... 73, Frank K4FMH | ||
| N8NK | 2020-04-10 | |
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| Re: A 12-Volt 30 Amp Power Supply | ||
| I did the same thing using some free supplies that I got from a sign company when they went out of business. Mine are 5v but otherwise indentical. I have 3 in series, adjusted to 4.60v each. The spec application sheet addresses this- and only asks that a reverse biased 1N4008, etc, be placed across each output. After a long, long CW ragchew at the 100w level, the supplies still feel the same temp as the room. 73 Reply to a comment by : KT4WO on 2020-04-09 Put the supply under a solid 15 amp load and wait for the smell/smoke. been thru three. All diff. brands/sellers. They all look alike and smoke alike. I really wanted them to work. too bad. I'm sure that they work fine at 20 amp ICAS,(SSB) but not at a steady load. KT4WO | ||
| KT4WO | 2020-04-09 | |
|---|---|---|
| A 12-Volt 30 Amp Power Supply | ||
| Put the supply under a solid 15 amp load and wait for the smell/smoke. been thru three. All diff. brands/sellers. They all look alike and smoke alike. I really wanted them to work. too bad. I'm sure that they work fine at 20 amp ICAS,(SSB) but not at a steady load. KT4WO | ||
| KW9WK | 2020-04-09 | |
|---|---|---|
| A 12-Volt 30 Amp Power Supply | ||
| I haven't had any RFI issues at all. I even went as far as to hook up my radios to a 12v car battery, then cycle the power supply on and off to see there was any noise. Not a peep. I still put some ferrites on the AC and DC leads, just in case.... | ||
| K4FMH | 2020-04-09 | |
|---|---|---|
| A 12-Volt 30 Amp Power Supply | ||
| Hi, Thanks for posting your project, Greg. Have you checked on the RFI? Just curious... 73, Frank K4FMH | ||
| KW9WK | 2020-04-09 | |
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| A 12-Volt 30 Amp Power Supply | ||
| I've got 3 of these little jewels in service. 2 of them feed my TS-480HX (Needs 2 power supplies) and 1 for the misc. stuff normally powered by wall-warts. Cheap enough that if one dies, it's not a big deal $$-wise. Amazon has them for $20.00. I'll get a couple just for spares. | ||
| KB9OAK | 2020-04-09 | |
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| A 12-Volt 30 Amp Power Supply | ||
| Nice! I already have a power supply, but I might steal the battery box idea. | ||
| KJ4DGE | 2020-04-08 | |
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| Re: A 12-Volt 30 Amp Power Supply | ||
| What does that mean, well? Reply to a comment by : N2AYM on 2020-04-08 This looks suspiciously like a Mean Well Model SE-450-15 | ||
| N2AYM | 2020-04-08 | |
|---|---|---|
| A 12-Volt 30 Amp Power Supply | ||
| This looks suspiciously like a Mean Well Model SE-450-15 | ||