Power supply circuit for spark erosion
First Claim
1. A spark generator for the machining of an electrically conductive workpiece in a spark erosion plant across a spark gap formed between the workpiece and a tool electrode with substantially no ballast resistance, comprising a direct current power supply;
- at least one switching circuit connected in parallel with the power supply; and
a control device connected to each switching circuit;
each switching circuit comprising first and second switching elements, each switching element having a conductive and a nonconductive state;
a pulse transformer having a primary and secondary winding, the switching elements and the primary winding being connected in series circuit so that current from the power supply is applied to the primary winding when the switching elements are placed in the conductive state, and the secondary winding being connected in parallel with the spark gap; and
a unidirectional current conducting means associated with each switching element and operatively connected across the primary winding and the associated switching element to place the pulse transformer in a freewheeling state when only the associated switching element of the first and second switching elements is in the conductive state;
the control device being operatively connected to each switching element and adapted to selectively place each switching element in the conductive state in accordance with a predetermined pattern.
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Accused Products
Abstract
A circuit arrangement for producing machining pulses in a spark erosion installation from a direct current power source that functions without the use of ballast resistors. There are at least two controllable circuits which are parallel to the spark gap and to one another and whose output currents are additively superimposed for a total current flowing through the spark gap. The control inputs of the circuits are connected to a control circuit, which produces time-associated control signals, the nature of the time circuit cooperates with the control elements of the circuits, so that a current pulse is only allowed to pass to the spark gap if the switches controlled by the control elements are simultaneously open.
17 Citations
6 Claims
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1. A spark generator for the machining of an electrically conductive workpiece in a spark erosion plant across a spark gap formed between the workpiece and a tool electrode with substantially no ballast resistance, comprising a direct current power supply;
- at least one switching circuit connected in parallel with the power supply; and
a control device connected to each switching circuit;
each switching circuit comprising first and second switching elements, each switching element having a conductive and a nonconductive state;
a pulse transformer having a primary and secondary winding, the switching elements and the primary winding being connected in series circuit so that current from the power supply is applied to the primary winding when the switching elements are placed in the conductive state, and the secondary winding being connected in parallel with the spark gap; and
a unidirectional current conducting means associated with each switching element and operatively connected across the primary winding and the associated switching element to place the pulse transformer in a freewheeling state when only the associated switching element of the first and second switching elements is in the conductive state;
the control device being operatively connected to each switching element and adapted to selectively place each switching element in the conductive state in accordance with a predetermined pattern. - View Dependent Claims (2, 3, 4, 5, 6)
- at least one switching circuit connected in parallel with the power supply; and
Specification