High voltage rectifier and associated control electronics
First Claim
1. High voltage rectifier, in particular for use as a bias voltage supply in vacuum processes such as PVD coating processes, comprising an input transformer and also subsequent rectification, smoothing and switching units and also an arrangement for switch control in dependence on occurring overcurrents, characterised in that in each case, a rectifier (VA, VB, VC) fed from a secondary transformer winding is combined with a subsequent smoothing capacitor (C1A, C1B, C1C), with a first switch (S1A, S1B, S1C) serving as a DC converter for regulation of the output voltage, with a choke (L1A, L1B, L1C) serving for smoothing of the current ripple and also a capacitor (C2A, C2B, C2C) intended for smoothing of the output voltage, and with a second switch (S2A, S2B, S2C) controlled in dependence on occurring overcurrents into a rectifier stage (A, B, C) across the output of which there is connected a recovery diode (D3A, D3B, D3C);
- and in that the smoothing chokes (L1A, L1B, L1C) can be switched over by the respective second switch (S2A, S2B, S2C) to a first recovery circuit (S1A, L1A, D2A;
S1B, L1B, D2B;
S1C, L1C, D2C), wherein, prior to each switching off of the respective second switch (S2A, S2B, S2C) the associated first switch (S1A, S1A, S1C) is brought into the conductive state for a predetermined short period of time and is then switched off.
1 Assignment
0 Petitions
Accused Products
Abstract
A high voltage rectifier with provisions for rapidly limiting or discontinuing the current flow in response to the occurrence of overcurrents and rapidly restoring such current when the overcurrents cease. The rectifier comprises one or more stages, each stage comprising a rectifier fed from a secondary transformer winding, a subsequent smoothing capacitor, a first switch serving as a direct D.C. converter for regulation of the output voltage, a choke and capacitor for smoothing the current and a second switch, activated by overcurrents, such that the smoothing chokes can be switched over by the second switch into a first recovery circuit wherein, prior to each switching off of the respective second switch the associated first switch is switched on for a predetermined period of time and then switched off.
46 Citations
12 Claims
-
1. High voltage rectifier, in particular for use as a bias voltage supply in vacuum processes such as PVD coating processes, comprising an input transformer and also subsequent rectification, smoothing and switching units and also an arrangement for switch control in dependence on occurring overcurrents, characterised in that in each case, a rectifier (VA, VB, VC) fed from a secondary transformer winding is combined with a subsequent smoothing capacitor (C1A, C1B, C1C), with a first switch (S1A, S1B, S1C) serving as a DC converter for regulation of the output voltage, with a choke (L1A, L1B, L1C) serving for smoothing of the current ripple and also a capacitor (C2A, C2B, C2C) intended for smoothing of the output voltage, and with a second switch (S2A, S2B, S2C) controlled in dependence on occurring overcurrents into a rectifier stage (A, B, C) across the output of which there is connected a recovery diode (D3A, D3B, D3C);
- and in that the smoothing chokes (L1A, L1B, L1C) can be switched over by the respective second switch (S2A, S2B, S2C) to a first recovery circuit (S1A, L1A, D2A;
S1B, L1B, D2B;
S1C, L1C, D2C), wherein, prior to each switching off of the respective second switch (S2A, S2B, S2C) the associated first switch (S1A, S1A, S1C) is brought into the conductive state for a predetermined short period of time and is then switched off. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
- and in that the smoothing chokes (L1A, L1B, L1C) can be switched over by the respective second switch (S2A, S2B, S2C) to a first recovery circuit (S1A, L1A, D2A;
- 9. Electronic control circuit for a high voltage rectifier, characterised by a detection and regulation circuit which in dependence on the occurrence of an arc or a predeterminable maximum current, brings about a change-over from the voltage regulation used in normal operation to a regulation with current restriction, with the desired value of the current being at least substantially equal to the last transmitted actual value of the current prior to the occurrence of the arc, and with a switching back to the voltage regulation taking place with renewed adjustment of the output voltage to the maximum value as soon as the arc is quenched.
Specification