With the circuit diagram, explain the principle of lead-lag network.With the circuit diagram, explain the principle of lead-lag network.

Question

With the circuit diagram, explain the principle of lead-lag network.

Answer 1

A circuit in which output voltage leads or lags the input voltage is called a lead lag network. It has series combination of R₁ and C₁ and a parallel combination of R₂ and C₂. At low frequencies, series capacitor C₁ looks open and there is no output. At high frequencies, C₂ acts as short and no output is obtained. At some frequency f output is maximum if R₁ = R₂ = R and C₁ = C₂ = C, then frequency \(f=\frac{1}{2\pi RC}\)

At low frequencies, phase angle is positive and the circuit acts as a lead network. At high frequencies, phase angle is negative and circuit acts as a lag network.