LC circuit is a key companent in Theremin circuit. It is applied to almost every piece of circuit. And What is it and how does it work?
An LC circuit is an electric circuit consisting of an inductor, represented by the letter L, and a capacitor, represented by the letter C, connected together.
An LC circuit, oscillating at its natural resonant frequency, can store elecric energy See the animation at right. A capacitor stores energy in the electric field(E) between its plates, depending on the voltage across it, and an inductor stores energy in its magnitude field(B), depending on the current through it. If an inductor is connected across a charged capacitor, current will start to flow through the inductor, building up a magnetic field around it and reducing the voltage on the capacitor. Eventually all the charge on the capacitor will be gone and the voltage across it will reach zero. However, the current will continue, because inductors resist changes in current. The current will begin to charge the capacitor with a voltage of opposite polarity to its original charge. The charge flows back and forth between the plates of the capacitor, through the inductor.The energy oscillates back and forth between the capacitor and the inductor until (if not replenished from an external circuit) internal resistor makes the oscillations die out.
- In most applications the tuned circuit is part of a larger circuit which applies alternating current to it, driving continuous oscillations. If the frequency of the applied current is the circuit’s natural resonant frequency ,resonance will occur.
- Other application
- tuning radio transmitters and receivers
- provides voltage magnification
- provides current magnification