Patent US3875490A successfully refreshed from Google Patents.
US3875490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Battery charging equipment having a voltage divider including a capacitor and transistor
Assignee: Robert Bosch Photokino GmbH
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Filing: 1974-04-16
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Granted: 1975-04-01
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Expires: 1994-04-16
Abstract
Abstract A full-wave rectifier connected to an AC source supplies a pulsating DC voltage. A thyristor is interconnected between the output of the rectifier and the battery. A voltage divider including a capacitor and the emitter-collector circuit of a transistor is connected across the output of the rectifier. The voltage divider has tap connected to the gate of the thyristor. A voltage proportional to the battery voltage is applied to the base of the transistor. Variations in the emitter-collector resistance of the transistor, which correspond to changes in the battery output voltage determine the cut-in time of the thyristor. When the battery voltage is sufficiently high the thyristor blocks completely.
Inventors
- 👤 Karl Ackermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 22:56
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/90; H02J7/971; H02J7/975; H02J7/977; H02J7/96
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
183 words
In equipment for charging a battery from an AC source furnishing an AC voltage, in combination, full wave rectifier means for rectifying said AC voltage and furnishing a corresponding pulsating DC voltage at a first and second DC output terminal; electrical switch means having a main conductive circuit connected from said first DC output terminal to said battery and having a switch control electrode, for interrupting the charging current to said battery in response to a cut-off signal at said switch control electrode; a capacitor having a first terminal directly connected to said first DC output terminal and a second terminal directly connected to said switch control electrode; a variable impedance connected from said switch control electrode to said second DC output terminal, said variable impedance having an impedance control electrode, the impedance of said variable impedance varying as a function of the signal applied to said impedance control electrode; and additional circuit means for connecting said impedance control electrode to said battery in such a manner that the signal at said impedance control electrode corresponds only to the voltage across said battery.
Claim 2
Dependent Claim
183 words
In equipment for charging a battery from an AC source furnishing an AC voltage, in combination, full wave rectifier means for rectifying said AC voltage and furnishing a corresponding pulsating DC voltage at a first and second DC output terminal; electrical switch means having a main conductive circuit connected from said first DC output terminal to said battery and having a switch control electrode, for interrupting the charging current to said battery in response to a cut-off signal at said switch control electrode; a capacitor having a first terminal directly connected to said first DC output terminal and a second terminal directly connected to said switch control electrode; a variable impedance connected from said switch control electrode to said second DC output terminal, said variable impedance having an impedance control electrode, the impedance of said variable impedance varying as a function of the signal applied to said impedance control electrode; and additional circuit means for connecting said impedance control electrode to said battery in such a manner that the signal at said impedance control electrode corresponds only to the voltage across said battery.
Claim 3
Dependent Claim
32 words
Equipment as set forth in claim 1, wherein said variable impedance is a transistor having an emitter-collector circuit connected in series with said capacitor and having a base constituting said control electrode.
Claim 4
Dependent Claim
28 words
Equipment as set forth in claim 1, wherein said additional circuit means comprise a resistive voltage divider having a voltage divider tap connected to said impedance control electrode.
Claim 5
Dependent Claim
26 words
Equipment as set forth in claim 3, wherein said resistive voltage divider comprises at least one resistor having a resistance varying as a function of temperature.
Claim 6
Dependent Claim
17 words
Equipment as set forth in claim 1, further comprising a resistor connected in parallel with said capacitor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |