US3631314A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Circuit arrangement comprising a high-voltage transistor
Assignee: US Philips Corp
•
Filing: 1968-06-14
•
Granted: 1971-12-28
•
Expires: 1988-06-14
Abstract
Abstract A circuit for increasing the speed of collector current reduction of a high-voltage transistor, in which an impedance is connected in series with the base to restrict variation in reverse base current. The specification discloses embodiments in which the impedance is a parallel circuit of a resistor and diode connected in the pass direction of base-emitter current, and in which the impedance is a coil.
Inventors
- 👤 Wilhelmus Theodor Hetterscheid
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 18:04
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/01; H03K5/02; H03F; H03F3/00; H03F3/20; H03F3/21; H03F3/217; H03K17/00; H03K17/04; H03K17/041; H03K17/0412; H03K17/04126; H03K4/00; H03K4/06; H03K4/08; H03K4/48; H03K4/60; H03K4/62; H03K4/64
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
170 words
A switching circuit for switching a high voltage power transistor between a saturation condition and a cutoff condition comprising, means for controlling said transistor into the saturation condition, signal control means connected to supply a pulsatory switching signal between the base electrode and the emitter electrode of said transistor by means of a transformer winding, said pulsatory signal being of a magnitude and polarity to drive the transistor from saturation into cutoff, a load impedance connected to the transistor collector electrode, and means for limiting the variation in reverse base current flow that otherwise would occur due to said pulsatory signal driving the transistor from saturation into cutoff, said limiting means comprising a parallel arrangement of a resistor and a unidirectional current conducting element connected between the transistor base electrode and one terminal of the transformer winding, the current conducting direction of said element corresponding to the pass direction of the base-emitter junction of the transistor, and means directly connecting the other transformer winding terminal to the transistor emitter electrode.
Claim 2
Dependent Claim
170 words
A switching circuit for switching a high voltage power transistor between a saturation condition and a cutoff condition comprising, means for controlling said transistor into the saturation condition, signal control means connected to supply a pulsatory switching signal between the base electrode and the emitter electrode of said transistor by means of a transformer winding, said pulsatory signal being of a magnitude and polarity to drive the transistor from saturation into cutoff, a load impedance connected to the transistor collector electrode, and means for limiting the variation in reverse base current flow that otherwise would occur due to said pulsatory signal driving the transistor from saturation into cutoff, said limiting means comprising a parallel arrangement of a resistor and a unidirectional current conducting element connected between the transistor base electrode and one terminal of the transformer winding, the current conducting direction of said element corresponding to the pass direction of the base-emitter junction of the transistor, and means directly connecting the other transformer winding terminal to the transistor emitter electrode.
Claim 3
Dependent Claim
32 words
A circuit as claimed in claim 1 wherein said unidirectional current element comprises a diode and the magnitude of said pulsatory switching signal is below the zener breakdown voltage of the diode.
Claim 4
Dependent Claim
144 words
A switching circuit for switching a high voltage power transistor between a saturation condition and a cutoff condition comprising, means for controlling said transistor into the saturation condition, signal control means connected to supply a pulsatory switching signal between the base electrode and the emitter electrode of said transistor by means of a transformer winding, said pulsatory signal being of a magnitude and polarity to drive the transistor from saturation into cutoff, a load impedance connected to the transistor collector electrode, and means for limiting the variation in reverse base current flow that otherwise would occur due to said pulsatory signal driving the transistor from saturation into cutoff, said limiting means comprising impedance means including a coil connected between the transistor base electrode and one terminal of the transformer winding, and means directly connecting the other transformer winding terminal to the transistor emitter electrode.
Claim 5
Dependent Claim
144 words
A switching circuit for switching a high voltage power transistor between a saturation condition and a cutoff condition comprising, means for controlling said transistor into the saturation condition, signal control means connected to supply a pulsatory switching signal between the base electrode and the emitter electrode of said transistor by means of a transformer winding, said pulsatory signal being of a magnitude and polarity to drive the transistor from saturation into cutoff, a load impedance connected to the transistor collector electrode, and means for limiting the variation in reverse base current flow that otherwise would occur due to said pulsatory signal driving the transistor from saturation into cutoff, said limiting means comprising impedance means including a coil connected between the transistor base electrode and one terminal of the transformer winding, and means directly connecting the other transformer winding terminal to the transistor emitter electrode.
Claim 6
Dependent Claim
170 words
A switching circuit for switching a high voLtage power transistor between a saturation condition and a cutoff condition comprising, means for controlling said transistor into the saturation condition, signal control means connected to supply a pulsatory switching signal between the base electrode and the emitter electrode of said transistor by means of a transformer winding, said pulsatory signal being of a magnitude and polarity to drive the transistor from saturation into cutoff, a load impedance that includes the line deflection coil of a cathode-ray tube connected to the transistor collector electrode, the transistor base-collector junction diode serving as an efficiency diode for producing a sawtooth current in said deflection coil, and means for limiting the variation in reverse base current flow that otherwise would occur due to said pulsatory signal driving the transistor from saturation into cutoff, said limiting means comprising impedance means connected between the transistor base electrode and one terminal of the transformer winding, and means directly connecting the other transformer winding terminal to the transistor emitter electrode.
Claim 7
Dependent Claim
170 words
A switching circuit for switching a high voLtage power transistor between a saturation condition and a cutoff condition comprising, means for controlling said transistor into the saturation condition, signal control means connected to supply a pulsatory switching signal between the base electrode and the emitter electrode of said transistor by means of a transformer winding, said pulsatory signal being of a magnitude and polarity to drive the transistor from saturation into cutoff, a load impedance that includes the line deflection coil of a cathode-ray tube connected to the transistor collector electrode, the transistor base-collector junction diode serving as an efficiency diode for producing a sawtooth current in said deflection coil, and means for limiting the variation in reverse base current flow that otherwise would occur due to said pulsatory signal driving the transistor from saturation into cutoff, said limiting means comprising impedance means connected between the transistor base electrode and one terminal of the transformer winding, and means directly connecting the other transformer winding terminal to the transistor emitter electrode.
Claim 8
Dependent Claim
127 words
A transistor circuit comprising a high voltage power transistor, control means for supplying a pulsatory switching signal between the base and emitter of said transistor of a magnitude to drive the transistor alternately into saturation and cutoff, a load impedance connected to the transistor collector electrode, means for coupling said control means between the base and emitter of the transistor, said coupling means comprising impedance means connected between the control means and said base electrode for limiting the variation in reverse base current flow when said pulsatory signal drives the transistor from saturation into cutoff, said impedance means being operative to cause the reverse base current to flow for a longer time than it would otherwise flow in the absence of the impedance means in the circuit.
Claim 9
Dependent Claim
127 words
A transistor circuit comprising a high voltage power transistor, control means for supplying a pulsatory switching signal between the base and emitter of said transistor of a magnitude to drive the transistor alternately into saturation and cutoff, a load impedance connected to the transistor collector electrode, means for coupling said control means between the base and emitter of the transistor, said coupling means comprising impedance means connected between the control means and said base electrode for limiting the variation in reverse base current flow when said pulsatory signal drives the transistor from saturation into cutoff, said impedance means being operative to cause the reverse base current to flow for a longer time than it would otherwise flow in the absence of the impedance means in the circuit.
Claim 10
Dependent Claim
14 words
A circuit as claimed in claim 5 wherein said impedance means comprises an inductor.
Claim 11
Dependent Claim
40 words
A circuit as claimed in claim 6 wherein said control means includes a transformer having a primary winding connected to a source of pulsatory voltage and a secondary winding connected to the inductor and to the emitter of the transistor.
Claim 12
Dependent Claim
150 words
A transistor circuit comprising a transistor, an input circuit connected between the emitter and the base electrodes of said transistor, an output circuit connected to the collector electrode of said transistor, and means connecting a point of said input circuit to a point of reference potential, said input circuit comprising a source of a pulsatory switching signal whereby said transistor is periodically driven to a saturated state and to a cutoff state, said input circuit further comprising impedance means serially connected in the portion of said input circuit between said point of said input circuit and said base electrode for reducing the variation in reverse base current of said transistor during the transition period from the saturated to the cutoff state, thereby to increase the average differential coefficient of collector current with respect to time of said transistor during the terminal portion of the transition period of said collector current.
Claim 13
Dependent Claim
150 words
A transistor circuit comprising a transistor, an input circuit connected between the emitter and the base electrodes of said transistor, an output circuit connected to the collector electrode of said transistor, and means connecting a point of said input circuit to a point of reference potential, said input circuit comprising a source of a pulsatory switching signal whereby said transistor is periodically driven to a saturated state and to a cutoff state, said input circuit further comprising impedance means serially connected in the portion of said input circuit between said point of said input circuit and said base electrode for reducing the variation in reverse base current of said transistor during the transition period from the saturated to the cutoff state, thereby to increase the average differential coefficient of collector current with respect to time of said transistor during the terminal portion of the transition period of said collector current.
Claim 14
Dependent Claim
42 words
The circuit of claim 8 wherein said transistor is of the type having a collector layer of sufficient thickness such that a variation of the amplitude of blocking signals between the emitter and base electrodes have no substantial effect on said coefficient.
Claim 15
Dependent Claim
33 words
The circuit of claim 8 wherein said impedance means comprises a parallel circuit of a resistor and a diode, said diode being connected in the pass direction with respect to forward base current.
Claim 16
Dependent Claim
12 words
The circuit of claim 8 wherein said impedance means comprises a coil.
Claim 17
Dependent Claim
24 words
A circuit as claimed in claim 10 wherein the magnitude of said pulsatory switching signal is below the zener breakdown voltage of the diode.
References Cited (Backward Citations)
US3129354A
Cited
US3204145A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-27 | 1975-06-28 | 1975-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-27 | 1979-06-28 | 1979-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-27 | 1983-06-28 | 1983-12-28 | $7700.00 | Window Closed / Lapsed |