10299Views16Replies

Author Options:

Higher efficiency (high amp) 12V regulator alternative to 7812 Answered

I need a high efficiency 12V DC regulator to supply my thermoelectric modules (they're very inexpensive so I had no choice but to use them). I found that the modules are most efficient at 12V @ ~7A each. I could use many 7812s in parallel but they are too inefficient and too much energy is lost to heat. Is there any alternative? Electricity bills are going up so it'd be very good if I can find an extremely efficient step-down or step-up regulator, short of using an expensive 'gold standard' ATX PSU (which are usually upwards of 500W so the power savings don't matter).

Comments

The forums are retiring in 2021 and are now closed for new topics and comments.
0
StephanoH
StephanoH

4 years ago

Have you tried with the 78HXX series? The H is for High current, they take up to 5 amps, but maybe with two of them...

0
steveastrouk
steveastrouk

7 years ago

What load have you got ? A Pc supply might be the cheapest way to get a reasonably efficient supply.

0
arikyeo
arikyeo

Reply 7 years ago

I've thought about using ATX power supply (ie PC PSU), but the standard ones usually supply at least 450W nowadays, which is overkill. Adding to that, those '80 plus' PSUs are mostly above 600-750W, which is even more overkill. I only need at most ~85-100W of power, and don't want to waste all that extra power which I won't need.
Besides, spending that much money (>$100) for PSU totally cancels out the power savings that may arise from that compared to the linear regulators, and I'm on quite a tight budget here (which was why I got those really cheap peltier modules in the first place).

0
steveastrouk
steveastrouk

Reply 7 years ago

An ATX supply may well NOT supply enough 12V to run your cells. You aren't wasting power in a switcher, if you aren't using it. See if your 20 dollar PSU can supply 12V@7A.

You haven't said how much current you need yet.

0
arikyeo
arikyeo

Reply 7 years ago

P=VI right? Which means I'll need around 8A of current if I need 100W of power..

0
steveastrouk
steveastrouk

Reply 7 years ago

8A at 12V from an ATX PSU is a LOT. See my alternative suggestion.

0
steveastrouk
steveastrouk

Reply 7 years ago

Look at these.
http://www.ebay.co.uk/itm/12V-10A-120W-16-7A-200W-20-9A-250W-29-2A-350W-PSU-Power-Supply-Transformer-/190899007235?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&var=&hash=item2c7277af03