Electric discharge machining power supply circuit
First Claim
1. A control circuit for electric discharge machining, for supplying current to a spark gap between a workpiece and tool, comprising a DC source, an inductive circuit connected to the DC source through regulating means arranged to maintain a constant current in the inductive circuit, switching means connected to the inductive circuit and to the spark gap and operable to divert the current in the inductive circuit to the spark gap, and means for establishing a predetermined voltage across the switching means and spark gap.
1 Assignment
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Accused Products
Abstract
The power supply circuit has an inductor connected to a DC source through a regulating circuit arranged to maintain a constant current in the inductor. A MOSFET is connected to the inductor and to the spark gap so that when the MOSFET is conducting, current is diverted from the inductor to the spark gap. The frequency and mark-space ratio of switching of the switching device is controlled to control the machining process. A second switching device (40) is arranged to conduct when the voltage across a capacitor (34) exceeds a reference voltage. A diode (46) is used to return excess energy to the DC source.
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Citations
7 Claims
- 1. A control circuit for electric discharge machining, for supplying current to a spark gap between a workpiece and tool, comprising a DC source, an inductive circuit connected to the DC source through regulating means arranged to maintain a constant current in the inductive circuit, switching means connected to the inductive circuit and to the spark gap and operable to divert the current in the inductive circuit to the spark gap, and means for establishing a predetermined voltage across the switching means and spark gap.
Specification