*OT* - Electronic curcuit component help

[Daz155HGT]

I have been trying to find (without sucess), a voltage regulator that can handle 6A, can anyone help?

Currently outputing 16.89-16.93v and need 15v out @ 6A.

Can anyone help me?

Daz

 

[cynic-al]

you want to go from 18 to 12 at 6amps or mains to 12 at 6 amps?

so about 70watts?

hmmm. lol

 

[Anonymous]

Not what your thinking m8

I am building a home power supply for something i am inventing.

I have built the power supply, but it needs regulating...

At the moment it goes something like this.

230v mains into a step-down transformer.
Through a rectifier to get varying DC.
Smoothed with an electrolytic(sp?) capacitor.
Now i have a 16.89-16.93v DC output, which is already pretty smooth, but needs to be smoother and slightly lower voltage.

To get exacly what i need, i require 15v DC output capable of 6A. Which (hopefully) if my calculations are correct is 53w.

With regulators (as you probably know), you loose a bit of power, normally about 3v, i have seen a few which have low power loss (max 1.3v loss), which may be ok, but the largest i can find is only rated at 5A.

I have ordered one, which i am sure will work, but i'm betting will get slightly hot and require a heatsink. Ideally i want a variable (normally by resistors i think?) to get one that will not get so hot (as its in a pretty small space) and adjustable to exactly 15v DC.

Daz

 

[Tom]

6A is a lot for a linear regulator.

You will always get heat, (Vin - Vout)*current = the power the device will have to dissipate as heat.

I can't think of anything off the top of my head that will do 6A. 5A yes but not 6.

 

[Daz155HGT]

I can't think of anything off the top of my head that will do 6A. 5A yes but not 6.

Probably why i can't find one then...lol

Oh well, an overclocked 5A one it will have to be

Daz

 

[Owen]

Well Daz,

that sounds like a big job, is it 15V or 12V you want ?. if 15V, then i think the easiest way of doin it is a switching reg, and you may need a hefty mosfet, inductor and shottky diode. There are a few switch mode controller IC's (simple switchers) made by national semiconductor, and i think they have an online design tool on their website. try www.national.com .

Whats the big project hidden under a sheet anyway ? must be good if it draws that much current ..

Owen.

 

[cynic-al]

if it's from 230v have you looked at dasktop power supplies? i'm sure i've seen them upto 10 amp, infact i know someone with one which does something stupid like 30amp, although they are expensive.

 

[Anonymous]

@ Owen - You seem to know what your talking about, but i don't, thats why i'm keeping it simple...lol

As for what it is...sorry cant say yet (Patent pending)

@ Al - Yep, looked at desktop power supplies, but they are £50+ for what i need...

Why buy it when you can build it, especially as its only for testing

I had everything else lying around anyway (as you do)...lol

Daz

 

[Owen]

Daz,

for a simple step down regulator, the simple switcher chips would do the job. they require very few exernal components, and they are easy to get working. you can buy the stuff you need from RS (www.rswww.com) or farnell, if you really need to get this going.

whatever it is, hope it works anyway,

Owen.