Hey guys, I'm pretty new to Arduino I was wondering how i would go ahead and use a 5V 1A peltier device along with arduino. As I understand, the peltier device requires a lot more amperage than the Uno can supply. I really appreciate the help!
Specifically these products
Hi, welcome to the forum.
As you can read on the Adafruit website, it is 5V 1.5A "so we suggest our 5V/2A power adapter for use".
To turn the Peltier on and off, you can use a relay or mosfet.
If you have a Peltier element without anything attached, one side (the 'hot' side) might get too hot.
Peter_n:
Hi, welcome to the forum.As you can read on the Adafruit website, it is 5V 1.5A "so we suggest our 5V/2A power adapter for use".
To turn the Peltier on and off, you can use a relay or mosfet.If you have a Peltier element without anything attached, one side (the 'hot' side) might get too hot.
Hi, so along with the thermal sensor, will 2A be enough?
Yes. The Arduino board uses little current and the DS18B20 almost nothing.
Both Adafruit and Sparkfun sell the DS18B20 : Waterproof 1-Wire DS18B20 Digital temperature sensor : ID 381 : $9.95 : Adafruit Industries, Unique & fun DIY electronics and kits
They are also on Ebay : ds18b20 -without for sale | eBay
P.S.: You can use the "REPLY" button or the "Quick Reply" text field. There is no need to use "Quote" since my post is already there 
Ahh i see, So the MOSFET is also used to change the direction of current, if i want to switch between hot and cold? Or is this a different procedure?
A mosfet is only for on and off.
To change the voltage, you need a H-bridge.
Two simple relays can be used, or a H-bridge module.
This is a relay shield : http://www.seeedstudio.com/wiki/Relay_Shield_V2.0
The H-bridge modules are often used for motors, but can also be used for Peltier elements.
This might work: Pololu - DRV8838 Single Brushed DC Motor Driver Carrier
So this means that I would also need to reconsider the choice of power adapter as well right? Also, Thank you for the speedy replies
No, why do you think that ?
I assume that the Peltier does not require more that 1.5A at 5V.
So you need a relay or H-bridge module that can switch at least 1.5A.
If the relay can switch 10A, that's fine. If the H-bridge can switch 2A or 5A, that's okay.
Some relays need 12V to work, but let's not use those. I think for your project 5V relays are easier.
Not all H-bridge modules work at 5V for the output, so you have find one that does.
If you are considering reversing the direction of the Peltier cold/heat, you need to let the device rest for at least 5 minutes before reversing.
Paul
Paul_KD7HB:
If you are considering reversing the direction of the Peltier cold/heat, you need to let the device rest for at least 5 minutes before reversing.Paul
This is to... prevent sudden temperature changes from causing cracking and failure of the peltier junction, or is it something more complicated?
DrAzzy:
This is to... prevent sudden temperature changes from causing cracking and failure of the peltier junction, or is it something more complicated?
Just that. Mine ran for about a week, doing an immediate switch from cold to hot, then 15 minutes later an immediate switch back to cold. Only a single cycle per day. After adding a 5 minute pause between power, I found the place on the Peltier that was not properly sealed and moisture condensed inside the unit and ran out the bottom. That unit lasted just a couple of days. Am waiting for another Peltier device and will inspect it thoroughly.
Paul
If i use the h bridge will I still need the mosfet? I'm looking at this diagram and I dont see a mosfet anywhere on it.
No. A mosfet can be as a switch, to turn something on or off. An H-bridge is used to also change the polarity.
In the picture is a mosfet for the fan.
I dont actually require that fan. I just need to power the peltier device and change polarity. Will I need the mosfet for the peltier device?
Noooo, the H-bridge will do that.
Thanks Peter!