Attached is an image of the basic function I need to accomplish. It may be more clear than my words below:
I need to wire a Peltier Plate/Heat Sink/Fan Assembly adafruit.com product: 1335 Peltier Thermo-Electric Cooler Module+Heatsink Assembly - 12V 5A : ID 1335 : $34.95 : Adafruit Industries, Unique & fun DIY electronics and kits 12Volts DC 5amps.
Peltier plates or Thermo Electric Coolers (TEC) are a solid state refrigeration that is currently less efficient than normal refrigeration technology but may be used in certain circumstances. As I understand the technology, if the direction of the current is switched the plate will conversely heat itself. Ultimately I would like to wire an H-Bridge to change the polarity and accomplish this but to start, I simply would like to know all the components for rigging the peltier plate with a POT/PWM for varying the voltage, even if only in one direction of current.
Eventually I will need to backlight with both blue and red LEDs, an LCD display as a reading/rated value of the voltage. Blue for Current A, Red for Current B. The LCD display initially just needs to read the voltage but would also eventually like to set display to 1-5 for respective 0-12v scale.
I was reading up on some forums here and saw that H-Bridges are most frequently used for changing the polarity for small motors changing direction. Is that what I need? Below is a basic drawing of what I have described I apologize if wording is confusing. I do not know computer engineering at all but am ready to read/work.
Also I do not mean to insult but if the LCD display was not necessary would I be able to rig up potentiometer/transformer without needing an arduino? I am asking because I remember my Dad’s train set which converts wall outlet to DC and can vary direction/speed of the train given the transformer because of polarity/current regulation all without needing to write code. Isn’t this the same thing I am trying to do, is it possible without an arduino? Is there a modern transformer that does this? (My Dad's is massive so would like to update/be able to reverse engineer a new one if possible)
The ultimate goal is to have a voltage regulator-in the form of a dial-that when turned right varies from 0 to 12v on one direction of current and then simply could also vary the voltage the same way but with opposite current direction.
AKA the voltage regulator is also a switch for polarity in that it is off when vertical but can actuate current in both directions.
Lastly, the voltage would optimally be displayed on a backlit LCD but not in increments of 0-12 but 0-5 and would change color-either RED/BLUE depending on the current direction.
Does that make more sense?
Oh and it would be nice if all of this was powered by wall outlet but batteries initially are no problem. I realize this is a lot, especially for a newbie-I am not experienced so I appreciate any and all insight
A transformer is not at all useful for your purposes. Transformers are for AC signals, where you need DC Signals.
Assuming you want to just use it in one direction, its pretty easy to just add a single N-Type/NPN Transistor between the negathive of the plate and ground, and connect the positive side of the plate to +12V. You will need a power supply that can supply at least 5A of current at 12V. That is 60W, and you'll want to make sure you have a safety margin, so you'll probably want 100W or more if you ever plan on using the plate at full power for extended periods of time (And not generate a lot of heat). An H-Bridge would work, and you can probably dig up a 12V motor H-Bridge (which will work for your purposes) already assembled somewhere if you want to be able to reverse bias it. Then you can just PWM the transistor and it will allow you to control the voltage/on-time of the plate.
The biggest thing is since you are dealing with significant currents (5A) you definitely want to make sure your devices can handle the current required. I would also recommend a fuse, and make sure you don't need some form of protective diodes/caps to prevent overvoltaging your transistors.
I suggest a modern H-bridge such as one of the DC motor controllers offered by Pololu, who unlike eBay provide excellent product documentation and support. This one will work for your Peltier: Pololu - VNH5019 Motor Driver Carrier
You can regulate the heating/cooling effect by using a PWM output pin to enable the H-bridge. You will need a hefty power supply for the Peltier, hopefully capable of up to 10 amps. Jameco is a good source.
Keep in mind that Peltier devices are heat pumps, that is they move heat from one place to another. So, their effectiveness depends on how efficiently you transfer the heat from the device itself (some elements sandwiched between two ceramic plates) and the rest of the world. It helps to add thermal transfer grease between the various contacts.
THANKS! you guys def got me going in much better direction which will make this project much easier thank you!
Here is the best PWM/Assembly I found on eBay:
DC 6A 6-30V 200W Reversible Motor Speed Regulator Controller PWM Control http://www.ebay.com/itm/261313522455
However, this product for $40 is interesting and could be a sufficient display for me:
DC 24V Temperature Controller of Thermoelectric Cooler Peltier 7016K http://www.ebay.com/itm/150837683937
Would both work well with the 12V/5A as you guys describe needing enough voltage and current?
I'm also considering these other Peltier Assemblies from eBay as well:
Also so the reversible switch in those PWMs means I will not need to be H-Bridging and writing code.
Eventually though once these decisions are made I'm sure backlighting BLUE/RED will mandate arduino incorporation correct?
I realize these products won't let me switch the polarity and regulate voltage all within the same dial but I am ok with that for now and need to figure out whether these assemblies will be able to perform the task. The project includes automated heating and cooling of reusable glass water bottles so I think I may go with http://www.ebay.com/itm/201032879860 because of the massive heat sink which would be vital for long periods of cooling/heating right? The adafruit plate shows better performance in theory as it shows -3.6 Celsius whereas the eBay is estimating 5.8. Obviously both meet the temperature requirements of even freezers but in terms of handling cooling/heating of 16oz reusable bottles which is better in your opinions?
