Where can I purchase a thermoelectric generator?

[Pooty]

I am not an electrical engineer and my understanding of electric circuits is very limited but I was needing to power a 4.5 volt accelerometer by use of a thermoelectric generator. Does anyone have any suggestions on where I can pick one up?

 

[Fish4Fun]

The good news is you can actually purchase one here:

http://www.tegpower.com/index.html

The bad news is that you are going to need a lot of heat and a fair amount of "cold". For 6.3V @ 180mA it will take a nominal 48C (118F) temperature differential between your "heat source" and your "cold source". You may also feel a bit "ripped off", the price tag for this 1.13W is $500, though if you happen to have a 214C (417F) temperature differential, this same unit will provide slightly over 50W (31V @ 1.6A).

Good Luck!

Fish

 

[Jobrag]

Why does it have to be a thermoelectric generator? What is wrong with a simple DC power supply?

 

[Pooty]

Fish4Fun, thank you for the info. I am checking out the website right now. I was kinda afraid that was going to be the case. Since this thing is supposed to be used in realistic environments where we aren't going to be getting such a huge flux in temperature gradients, would it be more feasible to wire a lot of these units in parallel so as to increase their voltage. Also, another option is to use the thermo generators to recharge the batteries as opposed to powering the unit by themselves. If this were the case, do you believe this to be possible or more doable? Again, I know very little about electrical systems... I wired my cars alarm system once and was extremely proud of myself, so that goes to show you the extent of my knowledge... :)

If the system runs on 3 AAA batteries, that roughly equals 4.5 volts... correct? So, if the batteries were running the system and the thermo generator were just there to charge the batteries, would I need to find out the required current of the accelerometer? Thanks for any help.

 

[Jobrag]

Wiring units in parallel will not increase the output voltage, have you considered a solar panel and batteries?

 

[uart]

Since this thing is supposed to be used in realistic environments where we aren't going to be getting such a huge flux in temperature gradients,

Well what's "realistic" will depend a lot on what the application is. For application in an internal combustion engine for example then access to a large temperature differential is realistic. If your application doesn't have a significant heat source the thermoelectric probably isn't the best choice, in the same way that solar power mightn't be the best choice for something that doesn't get a significant amount of light.

What is the average power consumption you are attempting to provide and what is the operating environment of the device?

 

[sophiecentaur]

I am not an electrical engineer and my understanding of electric circuits is very limited but I was needing to power a 4.5 volt accelerometer by use of a thermoelectric generator. Does anyone have any suggestions on where I can pick one up?

I guess the obvious response to your query is to point out that people just don't tend to use thermoelectric generators. There will be a good reason for this; it is expensive and mostly not convenient.
There is one very common application of this form of generator and that is the thermocouple driven solenoid in many (old) gas boilers. You push the gas valve button in and ignite the pilot light. This soon heats up a thermocouple which supplies enough current to hold the solenoid against the spring as long as the pilot is alight. Pretty elegant but involves only a Watt or so of power.
It's also been used as an electrical generator in space probes - using a radioactive isotope as the energy source.
I don't think you have explained why the idea appeals to you so much.?

 

[Bob S]

This article discusses Linear Technology (www.linear.com) energy harvesting power supplies:

"Linear Technology manufactures a wide range of ultra-low power products targeted for Energy harvesting applications. Power management products that convert energy from Vibration (Piezo), PhotoVoltaic (Solar) and Thermal (TEC, TEG, Thermopiles, Thermocouples) sources provide high efficiency conversion to regulated voltages or to charge batteries and super capacitor storage elements. Boost converters that operate from as little as 20mV or Battery chargers with Maximum Power Point capability expand the possibilities for a wide variety of industrial automation and control, wireless sensor, transportation, automotive and building management applications. "

http://www.linear.com/pc/viewCategory.jsp?navId=H0,C1,C1003,C1799

Bob S

 

[russ_watters]

Note, you should be able to use any thermoelectric cooler as a thermoelectric generator, so you may be able to find cheaper ones optimized for lower delta-Ts.

 

[sophiecentaur]

But what sort of efficiency?
The electric coolers are absolute rubbish compared with compressors, afaik. They're just cheaper and make no noise.