Calculation formula of coupling coefficient k: k=π L (C-Cm). Coupling coefficient, in the circuit, in order to indicate the tightness of coupling between elements, the ratio between the actual mutual inductance (absolute value) between two inductive elements and its maximum limit value is defined as the coupling coefficient.
Circuit: a conductive circuit composed of metal wires and electrical and electronic components, called a circuit. The power supply is added to the input end of the circuit to make the input end generate potential difference, and the circuit can work when connected. The existence of current can be tested by some instruments, such as voltmeter or ammeter deflection, light bulb emission, etc; According to the nature of the current flowing, it is generally divided into two types: the circuit through which DC power passes is called "DC circuit", and the circuit through which AC power passes is called "AC circuit".
