US3820008A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Driving circuit for switching transistor
Assignee: Bull HN Information Systems Italia SpA
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Filing: 1972-12-26
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Granted: 1974-06-25
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Expires: 1992-12-26
Abstract
Abstract A circuit for controlling a floating voltage switch device employing a pulse transformer with separate primary, auxiliary and secondary windings. The windings are controlled by other portions of the circuit in such a way that when a current is supplied to the primary winding, the auxiliary winding is interrupted and vice versa. The circuit also includes a pair of series connected diodes which are in parallel with the auxiliary winding so as to permit the same to be fed only during a specified time interval.
Inventors
- 👤 G Guarnaschelli
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:52
CPC Classifications
H; H02; H02M; H02M3/00; H02M3/02; H02M3/04; H02M3/10; H02M3/145; H02M3/155; H02M3/156; H03; H03K; H03K17/00; H03K17/04; H03K17/041; H03K17/0412; H03K17/04126
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
198 words
A circuit for controlling the flow of current in a load comprising in combination: a switching transistor controlling the flow of the current in the load; a current switching circuit for switching a current either in a first or in a second leg, in response to external signals, said first leg being formed by the collector emitter path of a first transistor, said second leg being formed by the colLector emitter path of a second transistor, the base of said first transistor being fed by said external signal, the base of said second transistor being connected to a reference voltage; a pulse transformer, including a primary winding, a secondary winding and an auxiliary winding, the primary and the auxiliary windings having a first terminal connected together, the second terminal of said primary winding being connected to said first transistor, the second terminal of said auxiliary winding being connected to said second transistor through a first diode; the secondary winding being connected between the emitter and the base of said switching transistor; and a second diode connected between said first terminal of said primary and auxiliary windings and a point common to said second transistor and said first diode.
Claim 2
Dependent Claim
198 words
A circuit for controlling the flow of current in a load comprising in combination: a switching transistor controlling the flow of the current in the load; a current switching circuit for switching a current either in a first or in a second leg, in response to external signals, said first leg being formed by the collector emitter path of a first transistor, said second leg being formed by the colLector emitter path of a second transistor, the base of said first transistor being fed by said external signal, the base of said second transistor being connected to a reference voltage; a pulse transformer, including a primary winding, a secondary winding and an auxiliary winding, the primary and the auxiliary windings having a first terminal connected together, the second terminal of said primary winding being connected to said first transistor, the second terminal of said auxiliary winding being connected to said second transistor through a first diode; the secondary winding being connected between the emitter and the base of said switching transistor; and a second diode connected between said first terminal of said primary and auxiliary windings and a point common to said second transistor and said first diode.
Claim 3
Dependent Claim
41 words
The circuit of claim 1 further comprising, in combination, a Zener diode and an ordinary diode series connected across one of said windings so as to limit the inverse voltage applied between the base and the emitter of said switching transistor.
Claim 4
Dependent Claim
16 words
The circuit of claim 2 further comprising a capacitor connected in parallel to said Zener diode.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-24 | 1977-12-24 | 1978-06-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-24 | 1981-12-24 | 1982-06-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-24 | 1985-12-24 | 1986-06-25 | $7700.00 | Window Closed / Lapsed |