12 Volt Supply Needed.

[David Davis]

After many years of faithful service, my 12 volt power supply unit built by a professional electronics engineer, thanks Sparks, finally gave up the ghost. I have a battery charger which will run off mains power so all is not lost  but if I want to use my Hobby King X120 DC charger, I will need a 12 volt power supply unit. Any recommendations?

 

Coincidentally I have just had to replace the PSU to my PC. I believe that these produce a 12 volt supply. If that is the case, could I solder a couple of female ends onto its output cables and use one of those as my power supply?

[Frank Skilbeck]

David lots of YouTube videos on how to do this, here's one 

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[MattyB]

If you don’t want to read up and convert your own PC or (even better) server PSU, Coolice can sort you out with a ready to go version.

 

Edited June 19, 2023 by MattyB

[Dale Bradly]

yes you can. its a great easy little project, and potentially free since you have it.

something like this:

 

1. have a beer.

2. find the green wire (there's only one) and join it to a black wire.

3. have a beer.

4. yellow to black will give you 12V, something like 40A is typically available, plenty for running typical batt chargers from.

5. red to black will give you 5V. (perfect for setting up rx supplies/servo testing etc)

6. Put whatever plugs/connectors etc you want to suit on the ends of these wires, or even mount posts on the case of the PSU. 

7. Have a beer.

 

there's a million websites/20 min YT vids on how to do step 2 if you need more info.

 

There's a heap of other voltages available, but not of a lot of use for most of us. Some people will also suggest resistors across various outputs to maintain a constant load blah blah, but ive converted 3. The first one did, the other two didn't, and i can't tell the difference - that is i have 5V and 12V ready and waiting and no resistors in sight.

 

Unless of course the reason your PSU was replaced was it had failed!

 

 

 

[David Davis]

25 minutes ago, Dale Bradly said:

yes you can. its a great easy little project, and potentially free since you have it.

something like this:

 

1. have a beer.

2. find the green wire (there's only one) and join it to a black wire.

3. have a beer.

4. yellow to black will give you 12V, something like 40A is typically available, plenty for running typical batt chargers from.

5. red to black will give you 5V. (perfect for setting up rx supplies/servo testing etc)

6. Put whatever plugs/connectors etc you want to suit on the ends of these wires, or even mount posts on the case of the PSU. 

7. Have a beer.

 

there's a million websites/20 min YT vids on how to do step 2 if you need more info.

 

There's a heap of other voltages available, but not of a lot of use for most of us. Some people will also suggest resistors across various outputs to maintain a constant load blah blah, but ive converted 3. The first one did, the other two didn't, and i can't tell the difference - that is i have 5V and 12V ready and waiting and no resistors in sight.

 

Unless of course the reason your PSU was replaced was it had failed!

 

Both the PSU to my battery charger and the PSU to my Personal Computer failed at about the same time. They've both been dropped off at the local re-cycling centre.

 

 

[MattyB]

Given you are starting from scratch then I would definitely go the server PSU route, bit more expensive but more powerful and designed for long term usage.

Edited June 19, 2023 by MattyB

[Phil Green]

1 hour ago, Dale Bradly said:

...

4. yellow to black will give you 12V, something like 40A is typically available, plenty for running typical batt chargers from.

5. red to black will give you 5V. (perfect for setting up rx supplies/servo testing etc)

...

 

Just to clarify Dales wording, 12v is between yellow and black, and 5v is between red & black - don't join yellow to black or red to black!!! 

[steve too]

2 hours ago, David Davis said:

Any recommendations?

 

Are you a cheque book modeller or a proper model aero engineer?

 

If you are the former, buy a ready to use PSU from one of the electric flight places.

 

If you are the latter, go to ebay, search for 'server psu' and see what is being recycled for between £10 and £25 and outputs 12V. Then go to the RCG Batteries and Chargers forum and search for the model number to see if anybody has worked out how to hack it. Be careful with the model number. If somebody has published instructions, buy the PSU and hack it.

 

2 hours ago, David Davis said:

Coincidentally I have just had to replace the PSU to my PC.

 

Did you replace it because it stopped working...

Edited June 19, 2023 by steve too

[Cuban8]

Maybe repair the original power supply - would save a lot of bother.

[David Davis]

Gentlemen! I appear not to have made myself clear.

 

1. I had a big heavy 12 volt Power Supply Unit made by a professional electronics engineer who sometimes posts as Sparks on this forum. He was going to throw it away because he had built or bought a better PSU. I took custody of it and for many years it worked well supplying my Hobby King charger. Then it packed up but this was not a problem because I had another simpler charger which worked off the mains but if I wanted to use the Hobby King Charger I would need to replace the PSU.

 

2. At about the same time as my big heavy 12 volt PSU packed up I was having problems with my Personal Computer. A qualified computer engineer diagnosed a faulty PSU so I bought a new one for about 20€; I live in the middle of France. It is powering my computer as I type this.

 

3. I took both of the faulty Power Supply Units to the local recycling centre and left them in the electronics department to be stripped for useful parts presumably in the Third World, so now I have neither of the original PSUs.

 

4. I do not regard myself as a cheque book modeller, I have been described as a traditional modeller in the past and all of the models I own with two exceptions, an Acrowot ARTF and the club's Boomerang trainer, I have built myself from kits or plans. However, I regard time spent fiddling with electronic components to be time which could be better spent cutting balsa. Consequently I will buy a PSU from a specialist supplier providing the price is reasonable.

 

Thank you all for your advice.

[MattyB]

2 minutes ago, David Davis said:

4. I do not regard myself as a cheque book modeller, I have been described as a traditional modeller in the past and all of the models I own with two exceptions, an Acrowot ARTF and the club's Boomerang trainer, I have built myself from kits or plans. However, I regard time spent fiddling with electronic components to be time which could be better spent cutting balsa. Consequently I will buy a PSU from a specialist supplier providing the price is reasonable.

 

In that case Coolice are the people to talk too - when I made mine, buying direct from them was only ~30-40% more than making it myself, so if I hadn't been interested in fiddling with PSUs for the fun of it one of their units would have been perfect.

 

http://www.coolice.co.uk/cccases/coolice-psu-s.html

[Paul De Tourtoulon]

No prices on the site,,,,

 

Ask around the club, maybe someone has an old psu and has the patience to fiddle with one.

[Frank Skilbeck]

If it doesn't have to be too high a power then a Laptop power supply may also do the job. I recently cut the end off one and soldered on an XT60 connector and it now powers an old ProPeak programmable charger which can handle Nimhs, Nicds, Pb and Li-ion. I think the one I have is rated at 14v and 5 amps.

[Mike T]

The HP Proliant server PSU hacks are so simple I really wouldn't bother considering anything else (but the PC PSU hacks are good if you want a variety of voltages).

 

MattyB linked the relevant thread; all the info is in there and the HP hack pretty much meets the OPs desire to just 'solder a couple of female ends'...

[David Ovenden]

Yes, that's what I have and it works brilliantly.

43 minutes ago, Mike T said:

The HP Proliant server PSU hacks are so simple I really wouldn't bother considering anything else

The HP Proliant server PSU is what I have  it's an easy mod and provides a top rate powersupply   

[Geoff S]

6 hours ago, MattyB said:

If you don’t want to read up and convert your own PC or (even better) server PSU, Coolice can sort you out with a ready to go version.

 

 

Still going strong - I used it yesterday.  Not sure if they're still available on eBay but IIRC mine was < £20.

[Philip Lewis 3]

Just a bit of advice to anyone going down this route from someone who has made dozens and dozens of them from the Spasunm Power One server supply, (87 amp output will power multiple chargers), never pay the going rate on e bay for them, there is virtually no demand at all for these, the last lot that I bought were advertised at £30 each plus postage (these are heavy items) so I offered £100 for the dozen they had including postage and they accepted within minutes.

 

I think the sellers of these will virtually give them away just for a sale that shows that they have disposed of these responsibly.   

Edited June 19, 2023 by Philip Lewis 3

[Geoff S]

Are these power supplies replaced as a matter of course simply because of their age?  They are incredibly good and well suited to our purposes.  The only drawback is their shape but that's not a big deal. 

[GrumpyGnome]

12 hours ago, steve too said:

 

Are you a cheque book modeller or a proper model aero engineer?

 

That's a tad offensive ........... I presume you label yourself as the latter?

 

Personally, whilst I am not "a cheque book modeller" I would not want to attempt make my own PSU as I am not professionally qualified electrician, and, having a background that includes insurance, am fully aware that establishing possible culpability in any claim is a key directive....

[Philip Lewis 3]

These server power supplies are simply replaced like the same company replaces their cars, at a certain age they are replaced, these supplies typically are powering Bank servers and very large company servers and the cost of them going down is so great it's not worth the risk.

 

Bear in mind they also are run 24/7/365 so we should get years of use out of them (I haven't had one fail yet).

 

The shape is fantastic, very compact for what they do.

 

And yes they are great value.

 

Last comment, no you cannot gang these together to make 24 volts without making substantial alterations but luckily there is no real need to do so. 

Edited June 19, 2023 by Philip Lewis 3
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[MattyB]

8 hours ago, Philip Lewis 3 said:

Last comment, no you cannot gang these together to make 24 volts without making substantial alterations but luckily there is no real need to do so. 

Actually you can do exactly that with many of them - my setup uses two HP Proliant units in series,  and I competed the conversion in a few hours following instructions in the RCGroups thread and has run faultlessly ever since. It is a little more involved but there is a clear value in doing so for me, as many of the higher power chargers like my iCharger 406 require a 22-24V supply to operate at full power. 

[MattyB]

Here are the relevant links to support the above:

• RCGroups post 1 - server PSU conversions thread
• HP DP600 thread (the one I went for)
• Floating the DC ground (a necessary step for one of the PSUs when operating in series)

Edited June 20, 2023 by MattyB

[Learner]

1 hour ago, MattyB said:

Actually you can do exactly that with many of them - my setup uses two HP Proliant units in series,  and I competed the conversion in a few hours following instructions in the RCGroups thread and has run faultlessly ever since. It is a little more involved but there is a clear value in doing so for me, as many of the higher power chargers like my iCharger 406 require a 22-24V supply to operate at full power. 

Just out of interest, what batteries and how many at a time do you charge needing to use full power on a charger like that?

[MattyB]

6 minutes ago, Learner said:

Just out of interest, what batteries and how many at a time do you charge needing to use full power on a charger like that?

I’ve only done it a few times, but it can charge 6x 6S 5000s simultaneously in parallel (three per side) at around 1.6C. Useful at a site like Buckminster where I will have travelled a long way, there is a mains supply and i don’t want to travel with a large number of high capacity fully charged packs.

 

[MattyB]

Ps - Safety point:  For anyone wanting to do this, unless you are a highly experienced electronics expert please make sure that you a) only use 2x identical and well understood models of PSU where there is good guidance (inc. pictures) online showing how to float the ground, and b) follow the instructions carefully. If in doubt, read post 1 of the RCGroups thread on the safety requirements for connecting multiple supplies in series.