초록 ▼

An active clamp circuit for an inductive load switching circuit includes a zener current control resistor to set the breakdown current in a zener diode of the clamp circuit. The zener breakdown current is set at a sufficiently high level to ensure that the zener diode is operated at a point beyond i

An active clamp circuit for an inductive load switching circuit includes a zener current control resistor to set the breakdown current in a zener diode of the clamp circuit. The zener breakdown current is set at a sufficiently high level to ensure that the zener diode is operated at a point beyond its “knee”region and therefore does not generate interfering levels of microplasmic noise (MPN). The zener current control resistor is provided in addition to a circuit speed control resistor such that there is substantially independent control of the switching circuit operating speed and the breakdown current of the zener diode of the active clamp circuit.

대표청구항 ▼

A control circuit for switching current in a load which includes an inductive reactance comprising: transistor means including a control terminal and a primary current carrying path defined by a current input terminal and a current output terminal for switching current in the load through said prima

A control circuit for switching current in a load which includes an inductive reactance comprising: transistor means including a control terminal and a primary current carrying path defined by a current input terminal and a current output terminal for switching current in the load through said primary current carrying path which is connected to the load; first resistance means connected to said control terminal for determining the operating speed of said control circuit; inductive energy discharge control means connected between the load and said control terminal for activating said transistor means to thereby provide a current path through which the load is discharged, said inductive energy discharge control means including a zener diode connected to conduct inductive flyback current in a reverse direction therethrough; and current control means connected between said zener diode and a ground potential for determining the inductive flyback current through said zener diode whereby the speed of said control circuit and the zener breakdown current are each controlled to provide a desired operating speed and sufficient zener breakdown current to prevent the generation of microplasmic noise by the zener diode.