US5289101A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Battery charger with charging current controller
Assignee: OKAWA ELECTRIC CO Ltd
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Filing: 1991-04-24
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Granted: 1994-02-22
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Expires: 2011-04-24
Abstract
Abstract A battery charger includes a transformer having a primary coil and a secondary coil, a switch for duty control of a current flowing through the primary coil of the transformer, a detector for detecting a value of a current flowing through the secondary coil of the transformer, and a secondary controller for receiving the detected value from the detector and for outputting a charge control signal. The pulse of the charge control signal is modulated in accordance with the detected value by the detector. The battery charger further includes a light emitter controlled by the charge control signal for flickering, a phototransistor turning on and off according to the flickering of the light emitter, and a primary controller for converting the ratio of the time during on of the phototransistor to the time during off of the phototransistor into an analog value, and for outputting to the switch a pulse signal which is modulated to have a duty cycle corresponding to the analog value so as to control a duty cycle of the switch.
Inventors
- 👤 Masami Furuta
- 👤 Takao Iwatsuki
- 👤 Masatoshi Sugiura
- 👤 Toshio Matsumoto
- 👤 Hideki Watanabe
- 👤 Hideiki Niwa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:26
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/02; H02J2207/00; H02J2207/20
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
236 words
A battery charger with a charging current controller comprising: a transformer having a primary coil and a secondary coil; a switch for duty control of a current flowing through said primary coil of said transformer; a detector for detecting a value of a charging current flowing through said secondary coil of said transformer; a secondary controller for receiving the detected value from said detector and for outputting a charge control signal, the pulse width of which is modulated in accordance with the detected value by said detector; a light emitter controlled by said charge control signal for flickering; a phototransistor turning on and off according to the flickering of said light emitter; and a primary controller for converting the ratio of the time during on of the phototransistor to the time during off of the phototransistor into an analog value, and for outputting to said switch a pulse signal which is modulated to have a duty cycle corresponding to the analog value so as to control a duty cycle of said switch; a second detector for detecting a value of the current flowing through said primary coil of said transformer; a comparator for receiving the detected value from said second detector and for comparing the detected value with a predetermined value; and means for compulsory turning off said pulse signal which is applied to turn on said switch when the detected value exceeds said predetermined value.
Claim 2
Dependent Claim
236 words
A battery charger with a charging current controller comprising: a transformer having a primary coil and a secondary coil; a switch for duty control of a current flowing through said primary coil of said transformer; a detector for detecting a value of a charging current flowing through said secondary coil of said transformer; a secondary controller for receiving the detected value from said detector and for outputting a charge control signal, the pulse width of which is modulated in accordance with the detected value by said detector; a light emitter controlled by said charge control signal for flickering; a phototransistor turning on and off according to the flickering of said light emitter; and a primary controller for converting the ratio of the time during on of the phototransistor to the time during off of the phototransistor into an analog value, and for outputting to said switch a pulse signal which is modulated to have a duty cycle corresponding to the analog value so as to control a duty cycle of said switch; a second detector for detecting a value of the current flowing through said primary coil of said transformer; a comparator for receiving the detected value from said second detector and for comparing the detected value with a predetermined value; and means for compulsory turning off said pulse signal which is applied to turn on said switch when the detected value exceeds said predetermined value.
Claim 3
Dependent Claim
33 words
The battery charger as defined in claim 1 wherein said means for compulsory turning off said pulse signal internally includes a flip-flop circuit, so that said switch is turned on at each cycle.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-02-21 | 1997-08-23 | 1998-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-02-21 | 2001-08-23 | 2002-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-02-21 | 2005-08-23 | 2006-02-22 | $7700.00 | Window Closed / Lapsed |