US4570198A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low voltage alternator having short circuit protection
Assignee: STMicroelectronics SRL
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Filing: 1983-07-21
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Granted: 1986-02-11
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Expires: 2003-07-21
Abstract
Abstract In case of short circuit the overcurrent which passes through a detecting resistance in series with the excitation winding of the alternator operates a threshold current generator, which reduces the voltage of the central node of a voltage divider. A trigger interposed between said central node and an actuator circuit (for example a Darlington circuit) placed in series with the excitation winding of the alternator and with the above mentioned resistance turns off said actuator circuit, thus interrupting the current passage through the excitation winding. A filtering condenser associated to the voltage divider restores with delay the initial condition. The cycle is periodically repeated until the short circuit condition remains.
Inventors
- 👤 Sandro Storti
- 👤 Pietro Menniti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:43
CPC Classifications
H; H02; H02H; H02H7/00; H02H7/06; H02H7/065
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
138 words
An overload protection circuit for the excitation winding of a low voltage alternate or having a voltage regulator, said protection circuit including an input voltage divider having a filtering condenser and an actuator circuit placed in series with said excitation winding, the regulator being inserted between said divider and actuator circuit, the protection circuit further comprising a detecting resistor connected in series with said excitation winding and said actuator circuit, a threshold voltage generator placed in parallel with said filtering condenser and controlled by the voltage at the ends of said detecting resistance and a trigger circuit placed in parallel with said regulator between said voltage divider and said actuator circuit in order to control a brief cut-off of said actuator circuit when said generator is effected by an overvoltage produced at the ends of said detecting resistor.
Claim 2
Dependent Claim
138 words
An overload protection circuit for the excitation winding of a low voltage alternate or having a voltage regulator, said protection circuit including an input voltage divider having a filtering condenser and an actuator circuit placed in series with said excitation winding, the regulator being inserted between said divider and actuator circuit, the protection circuit further comprising a detecting resistor connected in series with said excitation winding and said actuator circuit, a threshold voltage generator placed in parallel with said filtering condenser and controlled by the voltage at the ends of said detecting resistance and a trigger circuit placed in parallel with said regulator between said voltage divider and said actuator circuit in order to control a brief cut-off of said actuator circuit when said generator is effected by an overvoltage produced at the ends of said detecting resistor.
Claim 3
Dependent Claim
34 words
Protection circuit according to claim 1, characterized in that said detecting resistor and said current threshold generator are operatively connected by means of a series of a detector circuit and of a delay circuit.
Claim 4
Dependent Claim
31 words
Protection circuit according to claim 2, characterized in that an output of said detector circuit acts on said actuator circuit in order to limit the value of the short circuit overcurrent.
References Cited (Backward Citations)
US3426265A
Cited
US3432726A
Cited
US3527997A
Cited
US3753079A
Cited
US3796943A
Cited
US3983471A
Cited
US3940572A
Cited
US4013925A
Cited
US4401937A
Cited
US4306184A
Cited
US4338646A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-10 | 1989-08-12 | 1990-02-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-10 | 1993-08-12 | 1994-02-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-10 | 1997-08-12 | 1998-02-11 | $7700.00 | Window Closed / Lapsed |