LF oscillation switching network - includes switching transistor with diode and resistor coupled between base and emitter integrated on one chip

摘要

The switching circuit uses a transistor (T) as the switching element. There is a diode (16) connected between the base and emitter in parallel with a resistor (17). All these elements are integrated on a single semiconductor chip (1). The collector of the transistor (T) is connected to one terminal of a transformer primary (LP). The secondary (LS) of the transformer has a number of diodes (23-26) connected to it. These diodes are associated with a number of capacitors. The emitter of the transistor (T) is connected to a feedback winding (27) in close association with the transformer primary. This winding is also connected via a diode (15) to a multi-terminal switching circuit (IC). The switching network is designed to perform an LF oscillation at between 20 and 50 Hz.