INA128: INA128

Hi Tomas,

have you measured the supply voltages? Take care, some PC power units require a minimum load to give correct output voltages... Also, they can be quite noisy. You should not use them.

Kai

I did. They are good with a dvm but I haven't use an oscilloscope. What would be a better choice for +/- 15VDC?

Thanks,

/Tomas

Hi Tomas,

Please include a copy of your schematic including the connections to the output of the device, power supply and the biasing of your thermocouple.

Hi Zak,

This is my schematic.

/Tomas

Hi Tomas,

your schematic looks good.

If the PC power supply produces overvoltages due to insuficient minimum load, then your INA128 might be destroyed allready. Especiially if it got hot during the testing. You should consider taking a fresh INA128 for the further experimenting.

I would test the circuit with two 9V alkaline batteries instead of the PC power supply.

Kai

Hi Kai,

Thanks for your feedback. I will try with two 9V batteries instead. I do believe that the INA128 is damaged already and I will replace. 

I will let you know how this works out.

/Tomas