LTC3108-1

qis,

I think I know why your output voltage is near zero.  I did a retest and accidentally reversed the thermal flow, and the output was then ~20mV just like yours.  TEG modules are standardized regarding the orientation of the junctions.  One must apply the cold surface to the side of the TEG which has the identification lettering.  The hot side is the surface without lettering.

FYI, with the test set described in my previous message with VS1=VS2=VAUX I'm getting about 4.5V when I should be getting 5V.  With VS1=GND and VS2=VAUX I'm getting 3.7V instead of 4.1V.  Either way it's about 0.5V off.  The LTC3108 system is working well enough for me to proceed.  Either the datasheet is simply wrong or there's something which isn't clear in the datasheet.  The energy conversion works, it's just grossly out of spec.

Steve 

qis,

I think I know why your output voltage is near zero.  I did a retest and accidentally reversed the thermal flow, and the output was then ~20mV just like yours.  TEG modules are standardized regarding the orientation of the junctions.  One must apply the cold surface to the side of the TEG which has the identification lettering.  The hot side is the surface without lettering.

FYI, with the test set described in my previous message with VS1=VS2=VAUX I'm getting about 4.5V when I should be getting 5V.  With VS1=GND and VS2=VAUX I'm getting 3.7V instead of 4.1V.  Either way it's about 0.5V off.  The LTC3108 system is working well enough for me to proceed.  Either the datasheet is simply wrong or there's something which isn't clear in the datasheet.  The energy conversion works, it's just grossly out of spec.

Steve