RLC circuit

Discussion in 'General Electronics Chat' started by acw_wellsy, Oct 1, 2006.

  1. acw_wellsy

    Thread Starter New Member

    Oct 1, 2006
    consider a series RLC circuit in which R is an incandescent lamp, C is some fixed capacitor, and L is a variable inductance. the source is 240 volts AC. Explain why the lamp glows brightly for some values of L and does not glow at all for other values???

  2. richbrune

    Senior Member

    Oct 28, 2005
    Inductors and capacitors in the right combination will allow more current to pass through them in what is called "resonance". Let's take an example of a .001 farad capacitor, in a 60hz series circuit, and find what inductor will allow the bulb to go brightest. L=1/(39.5*60*60*.001)=.00703 or about 7mH. If you move the variable inductor away from the 7mH value in either direction, the bulb will go dimmer.