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US4563596A Expired / Lapsed US ⏱️ 0.0 years remaining

Process and circuit for controlling the base drive of a power transistor

Assignee: Individual
•
Filing: 1983-12-20
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Granted: 1986-01-07
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Expires: 2003-12-20
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Abstract

Abstract The derivative of the collector-emitter potential of a transistor (T) relative to the base current is detected preferably by effecting a linear sweep of the base current, the value of this derivative is compared in a comparator stage (5) with a lower limit value and an upper limit value determining an optimum operation zone of the transistor in the vicinity of its quasi-saturation, and the base current is controlled by the result of the comparison. A high gain and an optimum operation of the power transistor (T) are achieved.

Inventors

  • 👤 Olivier L. Gosselin
  • 👤 Maxime Dessoude

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 23:45
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/06

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 52 words
A process for controlling the base drive of a power transistor, comprising detecting the collect-emitter potential, deriving the derivative of said potential, using a comparator to compare said derivative to upper and lower limits, integrating the comparator output to produce an integrated signal and controlling the base drive with said integrated signal.
Claim 2
Dependent Claim 52 words
A process for controlling the base drive of a power transistor, comprising detecting the collect-emitter potential, deriving the derivative of said potential, using a comparator to compare said derivative to upper and lower limits, integrating the comparator output to produce an integrated signal and controlling the base drive with said integrated signal.
Claim 3
Dependent Claim 18 words
A process according to claim 1, wherein the value of the derivative is derived in an analog manner.
Claim 4
Dependent Claim 27 words
A process according to claim 1, comprising varying the base drive current of the power transistor so as to produce a corresponding variation of the collector-emitter potential.
Claim 5
Dependent Claim 19 words
A process according to claim 3, comprising deriving the derivative of the detected collector-emitter potential with respect to time.
Claim 6
Dependent Claim 25 words
A process according to claim 3, comprising effecting a time base sweep of the base current which alternately increases and decreases with respect to time.
Claim 7
Dependent Claim 24 words
A process according to claim 5, comprising effecting said sweep by employing a current hysteresis in an induction coil when integrating the comparator output.
Claim 8
Dependent Claim 11 words
A process according to claim 5, comprising effecting a linear sweep.
Claim 9
Dependent Claim 24 words
A process according to claim 7, comprising effecting said sweep by employing a current hysteresis in an induction coil when integrating the comparator output.
Claim 10
Dependent Claim 107 words
A circuit for controlling the base drive of a power transistor having a base, a collector and an emitter, said circuit comprising means for detecting the collector-emitter potential, differentiating means connected to said detecting means for deriving the derivative of said potential, a comparator circuit having means for inserting in said comparator circuit upper and lower current limits and connected to said differentiating means for comparing said derivative with said upper and lower limits, integrating means connected to said comparator circuit for integrating the output signal of said comparator circuit and connected to said base of said power transistor for controlling said base with the integrated signal.
Claim 11
Dependent Claim 107 words
A circuit for controlling the base drive of a power transistor having a base, a collector and an emitter, said circuit comprising means for detecting the collector-emitter potential, differentiating means connected to said detecting means for deriving the derivative of said potential, a comparator circuit having means for inserting in said comparator circuit upper and lower current limits and connected to said differentiating means for comparing said derivative with said upper and lower limits, integrating means connected to said comparator circuit for integrating the output signal of said comparator circuit and connected to said base of said power transistor for controlling said base with the integrated signal.
Claim 12
Dependent Claim 87 words
A circuit according to claim 9, wherein said differentiating means comprise a differential amplifier responsive to the collector-emitter potential of said power transistor, a differentiator connected to the output of said differential amplifier and having an output connected to said comparator circuit, said comparator circuit comprising two comparators, one of which comparators is adapted to set said lower limit whereas the other of said comparators is adapted to set said upper limit, said comparator circuit having an output which is connected to control base current sweep means.
Claim 13
Dependent Claim 24 words
A circuit according to claim 9, wherein said integrating means includes a base current sweep means connected to said base of said power transistor.
Claim 14
Dependent Claim 17 words
A circuit according to claim 11, wherein said sweep means comprise an integrator generating a linear slope.
Claim 15
Dependent Claim 69 words
A circuit according to claim 11, wherein said sweep means comprise a circuit including an induction coil, an auxiliary transistor having a base connected to the output of said comparator circuit, a collector connected to the induction coil, which coil is connected to the base of said power transistor whose emitter is connected through a diode to a junction between said coil and said collector of the auxiliary transistor.

References Cited (Backward Citations)

US4055794A Cited
FR2534093A1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1989-01-06 1989-07-08 1990-01-07 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1993-01-06 1993-07-08 1994-01-07 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1997-01-06 1997-07-08 1998-01-07 $7700.00 Window Closed / Lapsed

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