US3878437A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Power output circuit for electrical discharge machining apparatus
Assignee: Individual
•
Filing: 1973-03-28
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Granted: 1975-04-15
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Expires: 1993-03-28
Abstract
Abstract An improved power output pulse amp circuit module for use especially in an apparatus for machining a conductive workpiece by passing electrical pulses between a tool electrode and the workpiece across an arc gap therebetween. The improved power output circuit module includes individual diodes in series with each output transistor to prevent sequential massive failure and also to protect each individual transistor against the second breakdown phenomenon. Optionally, the output circuit module may include a protector circuit for detecting the presence of a high voltage due to a breakdown, which protector circuit may be used to turn OFF the high voltage supply and also, optionally to turn ON an operator warning light until a repair or replacement has been made.
Inventors
- 👤 Seymour Cuker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:59
CPC Classifications
B; B23; B23H; B23H1/00; B23H1/02; B23H1/026; H; H03; H03K; H03K3/00; H03K3/01; H03K3/012; H03K5/00; H03K5/01; H03K5/02
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
363 words
In an apparatus for machining a conductive workpiece by passing electrical pulses between a tool electrode and said workpiece across an arc gap therebetween, wherein the improvement comprises: a first electronic control device having a collector electrode, an emitter electrode and a control electrode; a plurality of second electronic control devices each having a collector electrode, an emitter electrode and a control electrode; said collector electrodes of said first and second electronic control devices being electrically connected together; a first unidirectional electrical device electrically connected between said conductive workpiece and said collector electrodes of said first and second electronic control devices; a first resistive network electrically connected between said tool electrode and said collector electrodes of said first and second electronic control devices; first and second terminals electrically connected to said emitter electrode and said control electrode, respectively, of said first electronic control device; said emitter electrodes of said plurality of second electronic control devices being electrically connected to said first terminal; a plurality of second unidirectional electrical devices, each of said second unidirectional electrical devices being electrically connected to and associated with a respective one of said second electronic control devices in such a manner that said second unidirectional electrical device is electrically connected between said control electrode of its associated second electronic control device and said emitter electrode of said first electronic control device, pre-driver circuit means interposed between said first and second terminals and said first electronic control device, said pre-driver circuit including an additional electronic control device having an emitter electrode coupled to said control electrode of said first electronic control device through a parallel combination of a reactive element and a resistive element, said additional electronic control device having a control electrode coupled to said second terminal and an emitter electrode coupled to said first terminal; a protector circuit electrically connected to said emitter electrodes of said second electronic control devices for detecting a malfunction of any one of said second electronic control devices; and said protector circuit including a plurality of first resistive elements each being electrically connected between a respective emitter electrode of said second electronic control devices and at least a third unidirectional electrical device.
Claim 2
Dependent Claim
363 words
In an apparatus for machining a conductive workpiece by passing electrical pulses between a tool electrode and said workpiece across an arc gap therebetween, wherein the improvement comprises: a first electronic control device having a collector electrode, an emitter electrode and a control electrode; a plurality of second electronic control devices each having a collector electrode, an emitter electrode and a control electrode; said collector electrodes of said first and second electronic control devices being electrically connected together; a first unidirectional electrical device electrically connected between said conductive workpiece and said collector electrodes of said first and second electronic control devices; a first resistive network electrically connected between said tool electrode and said collector electrodes of said first and second electronic control devices; first and second terminals electrically connected to said emitter electrode and said control electrode, respectively, of said first electronic control device; said emitter electrodes of said plurality of second electronic control devices being electrically connected to said first terminal; a plurality of second unidirectional electrical devices, each of said second unidirectional electrical devices being electrically connected to and associated with a respective one of said second electronic control devices in such a manner that said second unidirectional electrical device is electrically connected between said control electrode of its associated second electronic control device and said emitter electrode of said first electronic control device, pre-driver circuit means interposed between said first and second terminals and said first electronic control device, said pre-driver circuit including an additional electronic control device having an emitter electrode coupled to said control electrode of said first electronic control device through a parallel combination of a reactive element and a resistive element, said additional electronic control device having a control electrode coupled to said second terminal and an emitter electrode coupled to said first terminal; a protector circuit electrically connected to said emitter electrodes of said second electronic control devices for detecting a malfunction of any one of said second electronic control devices; and said protector circuit including a plurality of first resistive elements each being electrically connected between a respective emitter electrode of said second electronic control devices and at least a third unidirectional electrical device.
Claim 3
Dependent Claim
36 words
The combination as set forth in claim 1, including: a plurality of third resistive elements each of which is electrically connected between said first terminal and a respective emitter electrode of said second electronic control devices.
Claim 4
Dependent Claim
23 words
The combination as set forth in claim 1, wherein said unidirectional electrical devices comprise diodes and all said electronic control devices are transistors.
References Cited (Backward Citations)
US3538303A
Cited
US3636381A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-14 | 1978-10-14 | 1979-04-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-14 | 1982-10-14 | 1983-04-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-14 | 1986-10-14 | 1987-04-15 | $7700.00 | Window Closed / Lapsed |