epsolutions
- Sep 7, 2019
- 106
- Joined
- Sep 7, 2019
- Messages
- 106
The circuit below is a thought exercise. The assumption is that an audio frequency signal is induced from an external source into the right-hand coil. At the same time is applied a 2Hz "gating" pulse at a voltage sufficient to power the LED. The two variable caps interactively tune the coil as well as the primary of an audio coupling transformer. The photo transistor is powered by 12VDC.
I would like to know 1) how the interaction of the two variable caps affects the behavior of the circuit and 2) how this interaction is modified by the opto coupling.
Please overlook any conceptual issues with the circuit itself which is speculative and not a final design. Apologies for the hand drawing. My schematic program refuses to work with my new Linux distro.

I would like to know 1) how the interaction of the two variable caps affects the behavior of the circuit and 2) how this interaction is modified by the opto coupling.
Please overlook any conceptual issues with the circuit itself which is speculative and not a final design. Apologies for the hand drawing. My schematic program refuses to work with my new Linux distro.
