I've just put together a circuit that takes an AC input, and shifts its phase between 0-90 degrees. I've included a slightly simplified circuit diagram as an attachment (the only difference is that I've strung two of these in series to increase the phase shift range).
I'm using a TL074ACN IC, powered by +/- 12 V, with 0.1uF capacitors to ground.
My input is +/- 2 V AC at 1kHz.
Here's my problem:
When I turn on the input voltage, the output looks fine. The phase shift works beautifully.
When I turn off the input voltage, the signal flatlines to zero, but then slowly rises to a DC 10 V signal and stays there. It's such a simple circuit, and I've checked and rechecked (and rechecked!) my wiring, that I'm clueless as to what could be wrong.
Any ideas?
I'm using a TL074ACN IC, powered by +/- 12 V, with 0.1uF capacitors to ground.
My input is +/- 2 V AC at 1kHz.
Here's my problem:
When I turn on the input voltage, the output looks fine. The phase shift works beautifully.
When I turn off the input voltage, the signal flatlines to zero, but then slowly rises to a DC 10 V signal and stays there. It's such a simple circuit, and I've checked and rechecked (and rechecked!) my wiring, that I'm clueless as to what could be wrong.
Any ideas?
Attachments
-
10.8 KB Views: 22