Control unit for A.C. regulator - has control circuit which utilises two contact-less switching devices operated in a mutually exclusive cycling mode

摘要

The control unit (ST) operates a contact less relay (X) which is coupled in series with a supply (S) and a load (Z). A second contact-less relay (Y) is in parallel with the load (Z). The function of the control cct. is to ensure that the two relays operate in a mutually-exclusive mode such that one relay is open when the other is closed and vice-versa. The relays are coupled to separate bridge rectifier ccts. and by varying the cycle of operation outputs of varying phase may be generated. In this way a wide range of a waveforms may be produced.