12v dc to 48v dc

[Drewcoolness99]

What would i need to convert my 12v from my psu to 48v? Need it for a project i am working on. And where would i get the parts?

 

[jpmkm]

I doubt you would be able to convert a pc power supply to output 48VDC. You would need a schematic and you would have to replace a lot of parts. You would be better off just getting or making a 48 volt power supply. I don't know how much current you need, but here is one for $29. Are you working with telephone equipment, by any chance? I know a lot of that stuff runs on 48VDC(actually -48VDC, I believe) because it's easy to power with batteries that way.

 

[Vertigo Acid]

Hmm, methinks that DC-DC step-up would be *much* easier to do than a AC-DC 48V PSU. Computer PSUs are well designed switched mode PSUs, whereas a standalone AC-DC would be linear simply because it's a PITA to roll your own SMPS. Granted the circutry to go DC-DC step-up would be linear, it would still be easier.

 

[kronchev]

Originally posted by Vertigo Acid
Hmm, methinks that DC-DC step-up would be *much* easier to do than a AC-DC 48V PSU. Computer PSUs are well designed switched mode PSUs, whereas a standalone AC-DC would be linear simply because it's a PITA to roll your own SMPS. Granted the circutry to go DC-DC step-up would be linear, it would still be easier.

this basically says it all. you can use a step-up transformer to get the higher voltages but theres a lot of extra crap involved, its really not worth it. just get a wall-wart.

 

[Anarchist4000]

If you could find anyone selling a 12V to 48V transformer you could use the PSU to supply it but your honestly better off just getting a wallwart or something to do the job.

On the other hand, depending on just how much power this thing needs and for how long you could use a ton of batteries to get the job done.

 

[HHunt]

I don't want to try, but could one chain four PSUs (12V to ground, using 12v on one end and ground on the other) ?

 

[jpmkm]

Originally posted by Anarchist4000
If you could find anyone selling a 12V to 48V transformer you could use the PSU to supply it but your honestly better off just getting a wallwart or something to do the job.

On the other hand, depending on just how much power this thing needs and for how long you could use a ton of batteries to get the job done.

Transformers don't work with DC. He would have to first convert the DC to AC, put the transformer in, and then rectify it back to DC. It would work, but he would need some hefty parts if he wanted more than about an amp out of it.

I don't want to try, but could one chain four PSUs (12V to ground, using 12v on one end and ground on the other) ?

NO!! Computer power supplies are grounded. If you hook the 12V of one power supply to the ground of another power supply, you are essentially tieing 12V to ground and shorting out the power supply. Your idea would work if the power supplies used a floating ground.

 

[Vertigo Acid]

http://www.maxim-ic.com/appnotes.cfm/appnote_number/710
A site explaining DC-DC Convertors, if you're really interested. It would take a bit of work, but you would be able to have some pretty high amperage output from a computer PSU. But, then again, if you're asking this sort of question, build your own might be out of the question. In all reality, if I were you i'd find some teleco power equpiment on e-bay. What's the project?

 

[HHunt]

Originally posted by jpmkm

NO!! Computer power supplies are grounded. If you hook the 12V of one power supply to the ground of another power supply, you are essentially tieing 12V to ground and shorting out the power supply. Your idea would work if the power supplies used a floating ground.

I was thinking of floating them off, so to speak, yes.

Detaching them from house-ground isn't too hard (Just plug them into a non-grounded socket), and insulating them from each other isn't heavy science either.

 

[plot]

Originally posted by HHunt
I don't want to try, but could one chain four PSUs (12V to ground, using 12v on one end and ground on the other) ?

possible, yes. would take some modifying of the PSU's though... basically, the power of one would be tied to the ground of the next. people often do this in electronic labs with bench power supplies... however, computer PSU's arn't the same.


as for converting 12v to 48v, would be easy if you developed a "clamper circuit", google it. only issues i'd see there is the power dissipation and heat factors at 48v.

 

[Anarchist4000]

Actually it might be just as easy to go on ebay, buy a used bench power supply and use that to get your power. Depending on how much current it can put out and how much is needed it might work. It would still have to be a hefty supply to get up to that voltage though.

DC-DC transformers do work they just tend to get extremely hot and would have to be well cooled.

If you gutted a second PSU and wired it properly you should be able to get 48 volts. However you'd have to tie both the +12V and -12V lines together to get the numbers you wanted.

 

[HHunt]

Originally posted by Anarchist4000
Actually it might be just as easy to go on ebay, buy a used bench power supply and use that to get your power. Depending on how much current it can put out and how much is needed it might work. It would still have to be a hefty supply to get up to that voltage though.

DC-DC transformers do work they just tend to get extremely hot and would have to be well cooled.

If you gutted a second PSU and wired it properly you should be able to get 48 volts. However you'd have to tie both the +12V and -12V lines together to get the numbers you wanted.

Only problem here is that the -12V line is usually rated for truly puny amounts of current compared to +12V, so it's only ok if you don't need too much of it.