Abstract: A high voltage power transistor circuit composed of a pair of transistors (TR1, TR2) serially connected through an inductor (L) to a supply voltage. Associated components are connected to the transistors which determine various periods of operation. In order to ensure that the transistors (TR1, TR2) are rendered non-conducting simultaneously, sensors (S1, S2) sense their change in base current to produce pulses in monostable multivibrators (M1, M2) whose relative phases are compared in a digital phase comparator (PC). The drive for each transistor (TR1, TR2) is provided by an associated driver stage (DR1, DR2) via an associated device (DC1, DC2) having a characteristic used to control the cut-off of its associated transistor. One of the devices (DC2) has a variable characteristic which is controlled by the output of the phase comparator (PC) to ensure the required simultaneous non-conduction of the transistors.

Abstract: A line output circuit has a transistor (TR) whose collector is connected through the primary winding (P) of a transformer (T) to a direct voltage supply terminal (2), the secondary winding (S) of the transformer (T) being connected through a diode (D1) to a terminal (3) at which an EHT supply appears. A diode (D2) shunts the collector-emitter path of transistor (TR) to provide a path for negative going sawtooth current. Two serially connected flyback capacitors (Cf1, Cf2) also shunt the transistor (TR), one capacitor (Cf2) being shunted by a switch (S1). The series arrangement of a linearity correction inductor (L1), a deflection coil (Ly), a further inductor (L2) and a trace capacitor (Ct1) also shunt the transistor (TR), the inductor (L2) and trace capacitor (Ct1) also being shunted by the series arrangement of a further trace capacitor (Ct2), a linearity correction resistor (R) and a switch (S2).

Abstract: In an amplifier circuit a first and a second transistor and a load resistor are connected between supply terminals. An input terminal receives an input signal, comprising two signal components having, respectively relatively high and low frequencies, for applying said input signal to the second transistor. The base of the first transistor is decoupled by a capacitor at the high frequency only which results in the first transistor amplifying the high frequency component while the second transistor amplifies the low frequency component.