Hello every one
I would like to power 9 peltier's which each are 12v - 14v at 6 amps @ max load, i have been testing them with a car battery but i would like to power them from the mains, to that i would also like to adjust the total output amps from say 30 amps to 60 amps with an arduino, or if that is too complex then adjusting the voltage should be sufficient.
What options do i have, such as a bridge rectifier ? I dont mind making it, in fact i would prefer to make it as i want to keep it small and integrated on a pcb and hopefully cheap ish, I don't have lots of electrical knowledge, but i am learning as i go. Can some one help me and design a wiring diagram if its not too hard. i have done loads of domestic electrics but in comparison very little electronics so i dont mind 230v 
Many thanks from Edwin
I don't know that much about Peltier devices, but I think the run them properly you're supposed to control the current (similar to how a high-powered LED is powered).
...Maybe a 60A car-battery charger will work?
You're going to need a rectifier, but you'll also need a step-down transformer. (And possibly some other circuitry.)
I doubt you can build a power supply for what you need... I'm not sure if you can even buy the components off-the-shelf. You'd probably want a switching power supply to keep the size & cost down and that makes it more complicated (and realistically, any voltage-regulated or current-controlled power supply is going to be a switching design).
And, if you start experimenting with high-current circuits you're probably going to fry a few components during development & testing, and that adds to the cost when you're making a one-off project.
A regular AC (non switching) [u]12V 6A transformer[/u] to power ONE of the devices is $28 USD and it's bulky.
Making such a power supply is way outside my skill level so I am sure it is outside yours.
HI,
I think you will need to buy / build an off line switching power supply. I say this because the current draw from a simple rectified AC waveform will be extraordinarily high. See the blue link in the attached. Energy is only obtained during the blue current pulse so to get a usable 60 amps will have to draw somewhere in the order of 120 amps during the current conducting phase.
Suggestion:
I would find 3 PC power supplies and add the 5V circuits together. I would put a 60Amp+ diode across each 5V output to protect if in case it was turned off while the others were on.
I would then build a buck converter to drop the voltage to your target voltage.
Good Luck
John
I would then build a buck converter to drop the voltage to your target voltage.
In all my years in electronics and managing specialists power supply engineeres. I have not met one that would be able to do that task without taking three or four prototypes to get the design right.
Ok i will not try to make the power supply then , So if i bought a £50 pc power supply which has 56 amps on the 12v rail.
850 watt pc power supply
Could i then take that 12v rail from within the power supply and just put it through a simple mosfet circuit to adjust the voltage pulses, i have made a mosfet circuit already for a large dc 12v fan which adjusts the speed with pwm and according to my voltage meter in turn adjusts the mean voltage accordingly from 0v to 14v. I would use this mosfet 60amp mosfet, 1v gate vh
Could i then take that 12v rail from within the power supply and just put it through a simple mosfet circuit to adjust the voltage pulses,
You could do that using PWM.
However some people on here with more experance of these devices than me say PWM is bad for the long term reliability, and others say it is not. So I can't say how good the solution would be.
I think the PC supplies might be a good 1st prototype but if you are not comfortable building a buck post converter you are better off with a commercial supply.
Look through eBay, there are a number of old used supplies that are quite robust.
Not worth making one when you can get this sort off of the shelf
Power Supply
