Patent ID: 6285253
Filing Date: 2001-09-04
Classification: H03F

Abstract:
An amplifier being susceptible to transient voltage signals to produce hum modulation in an output signal, comprising:a gain stage for amplifying an input signal and for generating the output signal;a bypass coil;a shunt capacitor associated with the gain stage that is physically and magnetically coupled to the bypass coil for use in removing the transient voltage signals, the shunt capacitor having a linear region of operation in which an electric flux density essentially varies linearly with an applied electric field and a non-linear region defined by a hysteresis loop; anda resistance connected in series with the shunt capacitor for dissipating energy;wherein the resistance reduces energy stored in the shunt capacitor so as to prolong operation of the shunt capacitor in the linear region and to allow the shunt capacitor to be better able to remove the transient voltage signals, thereby improving performance of the amplifier with respect to hum modulation.