Transformer

[BrettL]

Where to find a transformer 120v input output 18-24v capable of 200 amps?

 

[bharvey2]

BrettL,

That sounds like a pretty tall order! My first thought would be to look for an old, 120V AC welder although the open circuit voltage may be higher. Another idea may be to look for a Buck/Boost transformer and see if any can deliver 200A. I've never seem one that large but they might exist. What are you trying to accomplish?

bharvey2

 

[prcguy]

Do you need a transformer that will put out 18-24V AC or a power supply that will put out DC?

For just a simple transformer, 24V at 200A is 4,800 Watts and without any conversion for transformer efficiency that that would need at least 40A at 120V. Most houses have 20A breakers, so how are you going to feed it?
prcguy

Where to find a transformer 120v input output 18-24v capable of 200 amps?

 

[DJ11DLN]

Do you need a transformer that will put out 18-24V AC or a power supply that will put out DC?

For just a simple transformer, 24V at 200A is 4,800 Watts and without any conversion for transformer efficiency that that would need at least 40A at 120V. Most houses have 20A breakers, so how are you going to feed it?
prcguy

Which would require some special wiring...not going to get that much through 12-ga. Romex. I've never seen a 40A single-pole breaker, I don't think they make anything that large that isn't special-application, if at all. That would require, what, 6 ga. wire? Presuming the goal isn't to just cause a fire.:roll:

I'd look for something with a 240V input. Even if you could do this with 120V house current it will make your electrical utility very happy as the wheel in your meter imitates a helicopter taking off.

 

[BrettL]

I would like to make a variable power source from 120v/220vac to 12v-18vdc output. One transistor draws about 12-15 amps. There are 8 of them. I was just thinking of some headroom when I said 200 amps. I'm still in the learning stage. I just want a transformer that don't vibrate too bad or get hot real quickly. Some Mallory caps and a 200 amp bridge rectifier. Maybe a LM317 to control some TIP3055's. This may be overkill and I could save some money going another route. But hey, This will be my first power supply ever. With some study and what test equipment I have I can make it happen. All pointers are welcome.

 

[teufler]

I just got rid of a 75anp Astron suppy. Very heavy, what you are talking abvout would take a couple of guys to move it.

 

[BrettL]

75 amps would never run it efficiently. I think it's Po=100 at 12.5v 10a. So that's 80a easily with no headroom. So 150 amp powersupply? Or I could look into what the DaveMade guy put into his amps. My friend has a 150w radio to run into it. I was thinking of making him a power source for all the things he has helped me with fixing up my house. Just a thought.

 

[Thayne]

If you really want what you said, look up Buck-Boost type transformers, but like others have said it would be a 240V input and you would need a 2 wheel dolly to move it very far--

 

[BrettL]

Ok, what about using four 40 amp transformers ?

 

[mmckenna]

I'd look for a Telecom/Radio type DC rectifier plant. Much easier and designed for what you want to do.

You can find these in 24 volt version or 12 volt versions. The controllers will usually allow some adjustment of voltage range, but you won't get a 24 volt version down to 12 volts, and you won't get a 12 volt version up to 18.

Nice thing about telecom/radio rectifier systems is that they'll use modular/hot swappable switching power supplies, so adding enough modules to reach 200 amps of capacity is fairly easy.
As stated, you'll need more than a 15 or 20 amp household outlet. Ideally you might want to use a 240volt circuit as the source.

Other bonus on the Telecom/radio rectifier systems is that they'll allow hook up to a battery string. That not only gives you battery back up in the event of a power failure, but they also help smooth out any fluctuations.

Won't be cheap, though, unless you find a used one.

I've got some large 48 volt units at work. Not suitable for what you need, but the smaller ones will do 300+ amps no problem.


You could try looking at NewMar if you want to buy new:
Newmar | Scout DC Power System | 12 VDC | 95 - 200 Amps | 1,140 - 2,400 Watts

I've got a few of these at a couple of our radio sites. Might be a bit cheaper:
Integrated Power Systems | 12, 24 or 48 VDC | 11-40 amps They'll do 40 amps each and you can parallel them together.

Here's an 80 amp version:
Power Modules DC Power Systems | 12, 24 or 48 VDC | 560/1000/2200 watts

This system will do up to 432 amps:
Rack DC Power System; 12, 24 or 48 VDC, N+1 redundant DC Power systems

 

[mikewazowski]

Emerson, Alpha-Cordex, Marconi and Eltek all make rectifier bays that will do what you want but most are looking for 240v input.

 

[mmckenna]

Emerson, Alpha-Cordex, Marconi and Eltek all make rectifier bays that will do what you want but most are looking for 240v input.

Alpha makes really good stuff, I've been slowly replacing all my -48 volt DC plants with Cordex models or larger, along with the AMPS-24 inverter systems. Took some classes from them at their HQ outside Vancouver BC a year ago. Good company, stands behind their stuff.

Unfortunately, they'd don't make much in the way of large 12 volt systems. 24 volt systems they have, though.

 

[prcguy]

I was gong to tell the OP about building a large unregulated supply with a choke input and preload resistor like I made in high school in the 1970s, but the components would be very difficult to come by these days. I could go into more detail on this if interested.

I recently bought a slightly used Meanwell brand switching power supply on Ebay for about $100 that is rated 100A continuous at 15V +/- a few volts. You could get two of these and run them in parallel from different breakers at 120V or both from the 220V on a single breaker. This is probably the cheapest way to get the voltage and current being discussed. I use mine with a 500W SGC amplifier and the amp loves running from 15V.
prcguy

 

[WA0CBW]

What is the device you have that has 8 transistors that are drawing 12-15 amps each?
BB

 

[BrettL]

Dave Made 10 meter Amp.

Also I found some numbers on a transformer. If I knew what it meant and how to read them it would be great.


430-7001-4
EIM 6-9532
Class 180 H1
Mexico