How Can I Boost 55mV from a Peltier to 3V?

[John Rambosi]

I have a Peltier cooler and with the temperatures that I am using on either side, I am getting ~55mv. These temps cannot be changed however and I need the right step up so I can be getting about 3V's out of it, any links and info will be greatly appreciated!

 

[meBigGuy]

Look for single solar cell stepup converters.
Here is an example. I don't know how available it is.
http://www.akm.com/akm/en/product/datasheet1/?partno=AP4460A

EDIT http://www.linear.com/product/LTC3108

 

[russ_watters]

Note though that if you increase the voltage in that way, the amperage will drop.

 

[Jeff Rosenbury]

I assume this is for power generation?

Use 60 small coolers in series?

You might use something like the circuit meBigGuy presented with fewer elements, but even that needed 350mV input minimum.

All the voltage multipliers I know of use semiconductors which can't really switch at 55mV.

Of course you could treat the 55mV as a signal and amplify it, but that requires outside power.

 

[John Rambosi]

The other challenge to this is that I can't just put multiple peltiers in series because of size and space concerns.

 

[meBigGuy]

The linear tech device says : Operates from Inputs of 20mV

Not sure why I posted the link to the 350mv part. Maybe I grabbed the wrong one. I'll look again.

Note that for any stepup methodology, the total power (I * V) available remains constant (minus conversion losses)

Devices in series is nearly always better.

 

[John Rambosi]

The linear tech device says : Operates from Inputs of 20mV

Not sure why I posted the link to the 350mv part. Maybe I grabbed the wrong one. I'll look again.

Note that for any stepup methodology, the total power (I * V) available remains constant (minus conversion losses)

Devices in series is nearly always better.

Say I had to in series both putting out 55 mV what would the step up for that be (links?)

 

[meBigGuy]

That Linear Tech part works for 20mV to 500mV inputs. You can probably buy an eval board/reference design

There seems to be a lot of stuff under "energy harvesting"
http://www.digikey.be/en/techzones/energy-harvesting-solutions

Here are some product areas that may have solutions:
http://cds.linear.com/docs/en/product-info/EnergyHarvestingPartners.pdf

Here is an interesting board from TI
http://www.digikey.be/product-search/en?mpart=BQ25504EVM-674