Electrical Engineering ⇒ Topic : Hays Bridge

Hay's Bridge

Figure (a) shows the schematic diagram of Hay's bridge

                                             figure (a)

Let L₁ is inductance to be measured, R₁ is resistance of coil having inductance L₁. R₂, R₃, and R₄ are non-inductive resistances, and C₄ is standard capacitor

Equating real and imaginary parts,

                              ........... (1)

                                         ............ (2)

Solving Eqs. (1) and (2), we get

                              .............. (3)

                                .............. (4)

Q factor of the coil is given by

                             ................. (5)

Using Eq. (5), Eq. (4) can be written as:

                              ................. (6)

For higher value of Q, Eq. (6) reduces to

                                            ................ (7)