Let's say I have mentioned circuit and I want to be able enable/disable one of the 1uF capacitors to change the frequency of the LC circuit.
I would like to do this electronically with a micro-controller.
- I know a relay is ideal for this but is bulky and mechanical.
- Another option could be a an "analog switch ic" but they have a relative high internal resistance, and a low max current. The low max current is a problem for a parallel LC circuit because the current can go quite high.
Are there other solutions to do this?
Thank you in advance
- bigger picture: This is just a picture from the interwebs, but what I would like to make is very close to this, the inductor will be a large solenoid for vehicle detection. If the inductance changes (because of the presence of a car) the resonant frequency will change. The comporator will convert this attenuated oscillation in a block wave, the microcontroller can than determine the frequency of the block wave and so detect any changes (traffic).