switching PSU

Hey all...I am building a switching power supply for a 226w. TEC I am getting. So I have a few questions...

1. does the voltage of supplied to the tec matter or just the ampers?....basically....do I need 24 v and 9.5a or can i use 12v and 19a?

2. Is a switching psu the best option...or should I go linear?

3. What is the time constant on the standard 226w tec?

4. If I pulse about 50% of the time and run 28.9 v (basically 14.45v ) will that satisfy the tec.

5. anything else I should know before I burn up my proc?

Thnx for you help!

1. it matters (besides, how would you 'push' more ampers through it?).

4. i don't think it would be wise.

5. yeah.. it doesn't need to be extremely well regulated. a transformer(can be had for quite cheap) and bridging it to pulsing dc with 4 diodes(the name of the circuit in english eludes me right now) and couple of filter caps would be enough. i think there's one guide to creating such pelt powersupply here overclockers.com

grrh.. post brought only half of my order today :\ .. so can't play with my 226w yet..

1) You build a power supply to give you volts. Only rarely do you want constant current. therefore at 12V the peltier will draw whatever it's designed to draw

2) Switching = order of magnitude harder than linear, but an order of magnitude more efficient in this case. Linear with peltiers = heat, and a large electric bill

3) Time constant? wtf it's not capacitative

4) Don't know, we need Vmax, Qmax and Imax of the peltier

5) You do know how to do frequency-compensated voltage feedback, right?

Ok...I found this 75Amax. @ 28.9v X-former online that is built for switching PSUs.....I run it through a bridge rectefier then it will be around 27.5v dc....I filter it with a big cap so as to get as little ripple as possible. Ok so now I use a pulse modulator driving a power fet to get the volatage I want....with the info provided below will I be able to produce a stable PSU or will I need a different transformer?


Dangerden 226w
Maximum operating temp: 125 C
Imax = 24 Amps
Qmax = 226.1 Watts
Vmax = 15.2 Volts
Delta Tmax = >67 (C)

one word for you: read

it obvious you haven't done half as much reading as you should have. Here is an article on how to make a good, reliable switching power supply. Switching power supply

Also, follow this link for some more reading (they have a article on pulsing and many others). Good luck in your adventure

Thanx!!! All I wanted was someone who could answer my questions or a link that could....you delivered!....have a great one.