Circuit having improved firing angle symmetry for ignition pulses in the control of a multipulse rectifier

Abstract

Ignition control signals for a multipulse controlled rectifier are combined in a sequence which is fed through a first time delay stage to a phase control circuit having a voltage-controlled oscillator which generates a phase-locked, gated, highly accurate square-wave oscillation as a trigger pulse series. The ignition control signals and the trigger pulse series of the voltage-controlled oscillator are conjunctively coupled in and gates are then amplified to form firing (ignition) pulses. A second time delay stage is provided for safety, in the event of dynamic control processes, and follows the first time delay stage. The output signals of the second time delay stage are linked to the ignition control signals in additional and gates and are subsequently amplified. Should the phase control circuit be unable to follow the changes of the ignition control signals in the event of dynamic changes in the control processes, the ignition pulse formed after the response delay of the second time delay stage is utilized.

Dependencies are inferred from the claim text.