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I am tring to design an RLC circuit with a low (<3Khz) resonance out of RLC circuit elements. The circuit must be underdamped. The lower the damping the better.

Originally I planned (and built) a RLC circuit with R=.1, C=100uF, L=100uH. On paper this gives a resonance at 1590 and a damping factor of .05, perfect. But, when I am actually driving this thing my source is current limited to 10mA. The Current/Voltage transfer function of a series RLC circuit with these values has a gain of ~10 at resonance, meaning I have a max of 1mV driving voltage when operating at resonance. Too low. My driving voltage will have to be at least 50mv, preferably more.

The Current/Voltage transfer function is scaled by changing the resistor value. A resistor value of 10Ohm gives a good gain (.1 at peak), however the system then becomes severely overdamped. To compensate I would have to up the inductance by the same factor of 100, but 10000uH inducters are hard to come by.

Is there any other RLC circuit design that I can use that gives me an underdamped resonance below 3kHz, and doesn't require more than 10mA current from a reasonable (>10mV) drive voltage?

I've looked at some other designs (R || L || C) or ( R - [L || C] ) but the current/voltage transfer functions of these seem to have infinite gain at some frequencies (unless I made an error in my math).

thanks

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# Best RLC circuit for Low Frequency underdamped resonance

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