Peltier help please!

A

azherfer

Evolving Lead Gorilla
Okay, need a little help here, because when it comes to anything electric, I am as dumb as they come. I have a cabinet humidor and I decided to add a thermo-electric cooling unit. So off I went and bought one this one:

http://www.electronickits.com/kit/complete/peltier/ck500.htm

Of course, I expected this to come with layman terms instructions, but wasn't so lucky. So, I have no clue what I need to do to hook this up, and no clue what to buy in respect to a AC adapter, and no clue what to do when I get the AC adapter. If anyone has done this and has a kind bone in their body, help a fool out.

Thanks!
 
I have several of the peltier devices you have purchased.

I have two desk top (100 count each) humidors. Inside what could be best described as a styrofoam cooler with 2 inch thick walls.

You will need a power supply, a second fan and heat sink for each peltier module, heat transfer paste, and a control or thermostat to regulate the temperture.

I bought my power supply from: http://www.mpja.com/
I purchased a rather large power supply item # 15078 PS

For temperture control I built the circuit I found at:
http://ourworld.compuserve.com/homepages/Bill_Bowden/page2.htm#therm.gif
I used the circuit titled: Electronic Thermostat and Relay Circuit.
You need to be sure to flipflop the 5K pot and thermister to have the unit turn on when the temp is to high and shut off at the set temp.
All the parts for the circuit as well as the heat transfer paste were bought from: www.mouser.com

You said you were electrically challanged so this may be a place to start but, you will need more guidance.

One quick basic note: Mount the fan to the heat sink. You hook the red fan and peltier leads to positive 12V DC. The black fan and peltier leads are connected to 12V negitive DC. This will cause the fan to run and the heat sink to get warm and the other side of the peltier module to get cold.

I might be able to share more information as needed, but a disclaimer is in order. This works for me. Others my have similiar results, but your results my vary.

Shark
 
Last edited:
shark said:
For temperture control I built the circuit I found at:
http://ourworld.compuserve.com/homepages/Bill_Bowden/page2.htm#therm.gif
I used the circuit titled: Electronic Thermostat and Relay Circuit.
You need to be sure to flipflop the 5K pot and thermister to have the unit turn on when the temp is to high and shut off at the set temp.
All the parts for the circuit as well as the heat transfer paste were bought from: www.mouser.com
Click to expand...

Since he is weak in electronics - I doubt he will be able to build a thermostat from those directions. May be best just to buy a cheap thermostat and then get a relay or two.

And looking things over - looks like there is a built in thermostat on the device. That's not going to work for this application it would seem.

I'm installing peltier's in my cabinet - but went with a different model that already has heat sinks on both sides - and no thermostat.


Ron
 
Last edited:
RGD said:
Since he is weak in electronics - I doubt he will be able to build a thermostat from those directions. May be best just to buy a cheap thermostat and then get a relay or two.

And looking things over - looks like there is a built in thermostat on the device. That's not going to work for this application it would seem.

I'm installing peltier's in my cabinet - but went with a different model that already has heat sinks on both sides - and no thermostat.


Ron
Click to expand...


Ron
You are right. The the thermal switch on the module he purchased is to be used in the heating mode. It prevents the peltier overheating if used in the heating mode.

Azherfer you could use any of the a thermostats like these pictured here:
http://www.northernbrewer.com/temp-control.html

They could be directly hooked up to the power supply. Turning the power supply on and off as needed to turn the cooling on and off.
 
shark said:
Ron
Azherfer you could use any of the a thermostats like these pictured here:
http://www.northernbrewer.com/temp-control.html
Click to expand...

Do I understand correctly that the Johnson has a 3.5 degree differential but the Ranco Digital can be programmed with a 1 degree differential?

I would prefer it if the unit turned on at say 70 and turned off at 69 rather than cooling all the way to 67.5 before it turned off. It might be worth the extra dollars.
 
scrapiron said:
Do I understand correctly that the Johnson has a 3.5 degree differential but the Ranco Digital can be programmed with a 1 degree differential?

I would prefer it if the unit turned on at say 70 and turned off at 69 rather than cooling all the way to 67.5 before it turned off. It might be worth the extra dollars.
Click to expand...


The Ranco has an adjustable temperture differential. It can be set from 1 degree to 30 degress differential. I own one of the Rancos. I use it to controll fermentation temps for beer. Works very well. I use temp diff. of 3 to 5 degress so the unit cycles on and off less. The air temp varies alot more than the contents.

My brother uses a Johnson it works great also. One major draw back that I see is if, you kink the cooper sensing line the unit no longer functions.
 
There is also this Digital Johnson controller which allows for 1 degree settings - and it's the one that I am going to use (already have it).

CLICK HERE

And it's at least 20 bucks cheaper than the Ranco.


Ron
 
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