I just bought two LM675s and want to use them in a bridge connection to get a high voltage amplifier. I tried building the circuit I was interested in and seen as it did not work I decided to test the op amp in a simple inverting or non-inverting amp configuration which did not work either.
I must be doing something wrong but I don't know what?
The problem:
When powering the LM675 from a dual power supply (+ and - together to form a floating ground and then + to Vcc and - to Vee) the moment the -Vee connection is switched ON the signal I'm measuring at the output drops to a negative DC value instead of 0 and no input signal (be it sin or rectangle) gets amplified?
I'm quite sure it's not a problem with the way I'm measuring the signal, as I've tried a regular o-scope (making sure the ground is connected to the common floating ground) as well as a PC oscilloscope PicoScope 3425 which is designed to measure floating signals and had the same problem.
Has anyone come across this before and might have a solution?
Thanks and Regards,
Sinziana
I must be doing something wrong but I don't know what?
The problem:
When powering the LM675 from a dual power supply (+ and - together to form a floating ground and then + to Vcc and - to Vee) the moment the -Vee connection is switched ON the signal I'm measuring at the output drops to a negative DC value instead of 0 and no input signal (be it sin or rectangle) gets amplified?
I'm quite sure it's not a problem with the way I'm measuring the signal, as I've tried a regular o-scope (making sure the ground is connected to the common floating ground) as well as a PC oscilloscope PicoScope 3425 which is designed to measure floating signals and had the same problem.
Has anyone come across this before and might have a solution?
Thanks and Regards,
Sinziana