Abstract: A level shifter receives a variable input voltage such as a beam current representative voltage of a cathode ray tube and produces an output voltage that changes when the input voltage changes such that the output voltage is level shifted relative to the input voltage. The output voltage is coupled to an input terminal of an error amplifier of a power supply voltage regulator of a television receiver. The level shifter includes a current mirror arrangement responsive to the input voltage. A band gap type voltage source determines the amount of level shifting that is produced by the level shifter.

Abstract: A signal to be delayed is applied to a frequency selective path including an inverting active bandpass filter and to a non-frequency selective path including a voltage-to-current converter. The paths are coupled to a signal combiner which produces an output current having a first component proportional to the output current of the converter and a second component directly proportional to the filter output voltage and inversely proportional to the value of a gain control resistor. The resistor is selected to provide a predetermined ratio of the output current components to provide an overall allpass characteristic for the delay circuit and biased to conduct no current under quiescent signal conditions thereby reducing power dissipation. Several circuits may be cascaded for such purposes as peaking and delay equalization in television receivers, video disc players or the like.

Abstract: A first amplifier compares an input signal with the sum of a position control signal and a first width control signal and a second amplifier compares the position control signal with the sum of the input signal and a second width control signal, the second width control signal being derived from the same source as the first. Output circuitry combines unipolar output currents produced by the amplifiers to provide a net output current which flows in one sense to a load when the input signal is more positive than a first level and flows in the opposite sense when the input signal is more negative than a second level. No output current flows when the input signal lies within a dead zone defined by said levels, the position and width of the dead zone being separately and non-interactively controllable by said position and width signals.

Abstract: The outputs of a pair of non-additive combiners are coupled to respective inputs of a differential amplifier and an a.c. signal to be amplified is applied to a selected input of one of the combiners. A control circuit operates in a first mode to apply control voltages to the combiner inputs for causing the one combiner to block the a.c. signal and also causing both combiners to apply a common mode input voltage of a first value to the amplifier inputs. In a second mode, the control circuit changes the values of the control voltages in a sense to cause the one combiner to pass the a.c. signal and to also cause both combiners to apply a common mode input voltage of a second value to the amplifier inputs whereby, in either mode, the amplifier produces a constant quiescent d.c. output voltage.