Process and circuit arrangement for the switching of short circuits of installations for the electrochemical removal of material

Claim 2

Apparatus for electrochemically machining comprising: means for establishing a working gap means for detecting a short circuit across said gap, shunt means electrically connected in parallel with said gap for diverting current from said gap when a short circuit is detected, and means for accelerating the diversion of current from said gap when a shOrt circuit is detected including means for producing in said shunt means an electrical pulse of such direction that it produces in said gap a current pulse opposing the fading short-circuit current.

Claim 3

Apparatus as in claim 1 wherein said shunt means includes first electrical switch means having a high-resistance state and a low-resistance state and which is switched from said high-resistance to said low-resistance state when said detecting means detects a short circuit and wherein said producing means includes a capacitor, means to charge said capacitor, second electrical switch means having a high-resistance state and a low-resistance state and which is switched from said high-resistance state to said low-resistance state when said detecting means detects a short circuit, and a transformer having its primary winding connected to said capacitor so that said capacitor discharges through said primary winding when said second switch means is switched to said low-resistance state and having its secondary winding connected to said first electrical switch means so that when said short circuit is detected a voltage is induced in said secondary winding which produces a current in said gap opposing the short-circuit current.

Claim 4

Apparatus as in claim 2 wherein said first and second switches are thyristors.

Claim 5

Apparatus as in claim 2 wherein said producing means further includes a diode connected in parallel with said capacitor.

Claim 6

Apparatus as in claim 1 further including circuit breaker means for interrupting the flow of current to said gap when said short circuit is detected.

Claim 7

Apparatus as in claim 1 further including mechanical switch means connected across said gap for providing an electrical shunt when said short circuit is detected.

Claim 10

A method as in claim 7 wherein said step of producing includes the step of discharging a capacitor through the primary winding of a transformer having its secondary winding connected to said shunt means so that a voltage is induced in said secondary winding which produces a current in said gap opposing the short-circuit current.

Claim 11

A circuit for accelerating, upon the occurrence of a short circuit, the deflection of current from a working gap for electrochemical machining into shunt means connected to said gap, having a high and low-resistance state and adapted to assume said low-resistance state upon occurrence of a short circuit comprising: a capacitor, means to charge said capacitor, transformer means having a first winding connected to said capacitor so that, when discharging, said capacitor discharges at least in part through said first winding and having a second winding connected to said shunt means so that said shunt means and said second winding are connected in series and together are connected in parallel with said gap, and switch means for permitting said capacitor to discharge at least in part through said first winding when a short circuit occurs so that a voltage in induced in said second winding which produces a current in said gap opposing the short-circuit current.

Claim 12

A circuit for accelerating, upon the occurrence of a short circuit, the deflection of current from a working gap for electrochemical machining into shunt means connected to said gap, having a high and low-resistance state and adapted to assume said low-resistance state upon occurrence of a short circuit comprising: a capacitor, means to charge said capacitor, transformer means having a first winding connected to said capacitor so that, when discharging, said capacitor discharges at least in part through said first winding and having a second winding connected to said shunt means so that said shunt means and said second winding are connected in series and together are connected in parallel with said gap, and switch means for permitting said capacitor to discharge at least in part through said first winding when a short circuit occurs so that a voltage in induced in said second winding which produces a current in said gap opposing the short-circuit current.

Claim 13

A circuit as in claim 9 wherein said shunt means and said switch means are both thyristors.

Claim 14

A circuit as in claim 9 further including a diode connected in parallel with said capacitor.