Pages: [1]   Go Down
Author Topic: Peltier heater Cooler changing current direction  (Read 222 times)
0 Members and 1 Guest are viewing this topic.
0
Offline Offline
Newbie
*
Karma: 0
Posts: 14
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Hi,
I want to built a pretty simple project with one peltier element where I can regulate the heat/cold with a pwm signal. which is so far pretty easy with one n channel mosfet and a 10k resistor. (http://garagelab.com/profiles/blogs/how-to-use-a-peltier-with-arduino)
I tried it and it worked perfectly.
My problem is I want to be able to change from heating to cooling on the same side.
I found something which looks pretty similar to the thing I want but unfortunatly it's only a picture from fritzing without any explanation or part list. (http://www.arduino-tutorial.de/2010/08/peltier-element/)
has anyone done it before?
and can share a simple schematic.
Logged

Offline Offline
Edison Member
*
Karma: 64
Posts: 2488
The last thing you did is where you should start looking.
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

You might want to use a DPDT relay controlled by the Arduino.
It would reverse the current to the element and is relatively easy to use.
Logged

Germany
Offline Offline
Jr. Member
**
Karma: 0
Posts: 76
just sun
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

I think you can use a 'MotorDriver' IC for this - or build your H-Bridge with discrete components...
Logged

0
Offline Offline
Newbie
*
Karma: 0
Posts: 14
Arduino rocks
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

I have never used an H-Bridge. can you do pwm with it?
and do you need anything other than the h bridge?
Logged

Oregon, USA
Offline Offline
Edison Member
*
Karma: 65
Posts: 2125
View Profile
 Bigger Bigger  Smaller Smaller  Reset Reset

Quote
I have never used an H-Bridge. can you do pwm with it?
Yes, that is one of their most important functions.
Quote
and do you need anything other than the h bridge?
Yes, a power supply and something to control the H-bridge, like an Arduino.
Logged

"It seems to run on some form of electricity"

Phoenix, Arizona USA
Offline Offline
Faraday Member
**
Karma: 39
Posts: 5557
Where's the beer?
View Profile
WWW
 Bigger Bigger  Smaller Smaller  Reset Reset

I have never used an H-Bridge. can you do pwm with it?
and do you need anything other than the h bridge?

Also, be sure to get an h-bridge that can handle the current needs of your peltier - for most (probably all?) peltiers, any simple L293 or L298 based h-bridge driver circuits will -not- be able to handle the current needs (even an L298 wired in parallel for 4 amps of output current).

You'll likely need something with 5 or more amps of current output capability (10 amps to be safe). That's not a small h-bridge, but it won't be horrendously expensive to purchase; you might even be able to build one (simplest would be to use a DPDT relay with contacts rated for 10 amps (easy to get).

You likely won't need any diodes on the output of the relay, since a peltier is not an inductive device (it won't hurt if they are already a part of the device, should you purchase the an appropriate h-bridge controller).
Logged

I will not respond to Arduino help PM's from random forum users; if you have such a question, start a new topic thread.

Pages: [1]   Go Up
Jump to: