# 2kw Power supply

Thread Starter

#### ahmelsayed

Joined Dec 1, 2011
2
Hello, Everyone

I'm trying to build a power supply that is nearly 2kW which supplies 48 Vdc and 40A. - I know it is high power but i want to build it at home -
so please, is there any suggestions ??

Thanks in advance

#### thatoneguy

Joined Feb 19, 2009
6,359
You would need to start with an outlet capable of at least 20A.

Most outlets in the US are 15 or sometimes 20A, except for 220V, which are 40A

#### thatoneguy

Joined Feb 19, 2009
6,359
Maybe a power supply from a welder? I picked up a 110A craftsman migwelder (runs off 120vac outlet) on craigslist for 80$. You could probably get one even cheaper if it had a bad wirefeed mechanism or something. I think it only puts ~20V though; but you could maybe find one that goes up to ~40V (that's the highest I've seen). if not, you may be able to modify it to put out 48V. just a thought, not sure how feasible it is. Those are mostly a transformer and high power rectifier, not usually meant for 24/7 100% duty cycle. The voltage and current limiting aren't "Regulated supply" quality, though some are fairly advanced, they still weigh a ton, need 220V, and cost quite a bit when you get to 2kW output. #### bountyhunter Joined Sep 7, 2009 2,512 Those are mostly a transformer and high power rectifier, not usually meant for 24/7 100% duty cycle. The voltage and current limiting aren't "Regulated supply" quality, though some are fairly advanced, they still weigh a ton, need 220V, and cost quite a bit when you get to 2kW output. Exactly, not regulated voltage supply. Look for a used Power Ten Inc supply or EMI (electronic measurements Inc) supply online. We made them in 19" rack 1 3/4" high and 3" high. Here's a 20V/50A unit for$600:

http://www.accusrc.com/ccp5640-powe...v--0-50a--1kw--120v-3300d-2050-3300d-2050.htm

We made them in dozens of different output voltage/current combos

150V/33A:

http://www.accusrc.com/commerce/ccp...5kw--requires-190-4600d-15033-4600d-15033.htm

#### thatoneguy

Joined Feb 19, 2009
6,359
Hello,

Farnell is selling the murata series.
There you have a 48 Volts 40 A powersupply for about 500 Euro:
http://nl.farnell.com/murata-power-solutions/d1u-w-2000-48-hb2c/psu-2000w-48v-12v/dp/1574404

Bertus
That is quite impressive. The 90A Inrush current is a bit high, but the size is smaller than I'd expected. 12" x 6" x 1.5". 22Watts per cubic inch. Plus an internal 12V 2A supply to run the fans.

For less than the transformer alone would cost for a linear supply.

Though I can't think of a use for a 48V supply. at all. It's in that "weird range" from 30 to 80 volts that doesn't seem to "fit" anything, other than as a +/- supply internal to an amplifier.

Thread Starter

#### ahmelsayed

Joined Dec 1, 2011
2
Thanks everyone,

but i don't want to buy it , i want to made it at home-it is a challenge-. I had the transformer needed and a bridge rectifier for it, but i can't find a regulator that can give me my desired output (48V/40A), so Is there any IC (regulator) can do that ?? if not, Is there any other way ??

#### kubeek

Joined Sep 20, 2005
5,757
Thanks everyone,

but i don't want to buy it , i want to made it at home-it is a challenge-. I had the transformer needed and a bridge rectifier for it, but i can't find a regulator that can give me my desired output (48V/40A), so Is there any IC (regulator) can do that ?? if not, Is there any other way ??
What transformer do you have? Volts, amps.

#### R!f@@

Joined Apr 2, 2009
9,750
OP must be crazy

#### kubeek

Joined Sep 20, 2005
5,757
So... You don´t wanna buy anything. That means you will wind your own from scrap metal? 2kW? That is absolutely bonkers.

#### Kermit2

Joined Feb 5, 2010
4,162
I have Two 48 Volt battery chargers(for Golf carts).

They are transformer based and are quite simple electronically. The output is actually around 58 volts DC(because of the battery charging requirements) and the DC has a significant amount of AC riding on it. They were only $200 each, so the price is good if just for the transformer they contain. The weight is around 45 pounds(about 20Kg). These units put out 25 amps @ 52 volts which is around 1.3 KW. To get any more than this you WILL need to use something other than a standard 120VAC outlet for a power input. #### bountyhunter Joined Sep 7, 2009 2,512 Thanks everyone, but i don't want to buy it , i want to made it at home-it is a challenge-. Actually, it's basically impossible for an amatuer. I used to do it for a living. #### bountyhunter Joined Sep 7, 2009 2,512 I have Two 48 Volt battery chargers(for Golf carts). They are transformer based and are quite simple electronically. The output is actually around 58 volts DC(because of the battery charging requirements) and the DC has a significant amount of AC riding on it. They were only$200 each, so the price is good if just for the transformer they contain. The weight is around 45 pounds(about 20Kg).

These units put out 25 amps @ 52 volts which is around 1.3 KW. To get any more than this you WILL need to use something other than a standard 120VAC outlet for a power input.
A battery charger like this is basically about as similar to a regulated power supply as a mouse is to an elephant.

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