US5742148A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Charge/discharge control circuit and chargeable electric power source apparatus
Assignee: Seiko Instruments Inc
•
Filing: 1993-11-17
•
Granted: 1998-04-21
•
Expires: 2013-11-17
Abstract
Abstract A chargeable power supply which has a charge/discharge control circuit is provided in which the service life of a secondary cell is prolonged. A voltage dividing circuit, an overcharge voltage detection circuit, an overdischarge detection circuit and a control circuit are connected in parallel to the secondary cell. The control circuit receives signals indicating the condition of the secondary cell from the overcharge/overdischarge voltage detection circuits and outputs a signal for controlling a switch circuit for disconnecting the secondary cell from external equipment, or to stop a charging operation by an external power source. The control circuit also controls a switching element provided in series with the voltage dividing circuit and reduces a current which flows through the dividing circuit. A current limiting means is provided to limit the current consumption of the charge/discharge control circuit. In one embodiment, a the current limiting device is a switching element provided in series with the voltage dividing circuit. In another embodiment, the current limiting device is an error amplifier with a latching function provided in an overcharge detecting circuit.
Inventors
- 👤 Minoru Sudo
- 👤 Takayuki Takashina
- 👤 Yoshikazu Kojima
- 👤 Sadashi Shimoda
- 👤 Hiroshi Mukainakano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 18:05
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/14; H02J7/1438; H02J7/50; H02J7/52; H02J7/56; H02J7/60; H02J7/663; H02J7/68; H02J7/855; H02J7/90; H02J7/94; H02J7/96; H02J7/63; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 40
Claim 1
Independent Claim
111 words
A charge/discharge control circuit comprising: voltage dividing means for dividing a voltage of an electric power source and producing a plurality of divided output voltages; overcharge voltage detection means and overdischarge voltage detection means for detecting a level of the divided output voltages from the voltage dividing means; control means for receiving and processing signals from the overcharge voltage detection means and the overdischarge voltage detection means and for outputting a signal for controlling a charge/discharge of the electric power source; and activating means connected in series to the voltage dividing means for selectively activating the voltage dividing means so as to limit the power consumption of the charge/discharge control circuit.
Claim 2
Dependent Claim
111 words
A charge/discharge control circuit comprising: voltage dividing means for dividing a voltage of an electric power source and producing a plurality of divided output voltages; overcharge voltage detection means and overdischarge voltage detection means for detecting a level of the divided output voltages from the voltage dividing means; control means for receiving and processing signals from the overcharge voltage detection means and the overdischarge voltage detection means and for outputting a signal for controlling a charge/discharge of the electric power source; and activating means connected in series to the voltage dividing means for selectively activating the voltage dividing means so as to limit the power consumption of the charge/discharge control circuit.
Claim 3
Dependent Claim
146 words
A chargeable electric power source apparatus having a secondary cell connected through a switching means to an external power source terminal, and a charge/discharge control circuit connected in parallel to the secondary cell for controlling the switching means, the charge/discharge control circuit comprising: voltage dividing means for dividing a voltage of an electric power source and producing a plurality of divided output voltages; overcharge voltage detection means and overdischarge voltage detection means for detecting a level of the divided output voltages from the voltage dividing means; control means for receiving and processing signals from the overcharge voltage detection means and overdischarge voltage detection means and for outputting a signal for controlling the charge/discharge of the secondary cell; and activating means connected in series with the voltage dividing means for activating the voltage dividing means so as to limit the power consumption of the charge/discharge control circuit.
Claim 4
Dependent Claim
146 words
A chargeable electric power source apparatus having a secondary cell connected through a switching means to an external power source terminal, and a charge/discharge control circuit connected in parallel to the secondary cell for controlling the switching means, the charge/discharge control circuit comprising: voltage dividing means for dividing a voltage of an electric power source and producing a plurality of divided output voltages; overcharge voltage detection means and overdischarge voltage detection means for detecting a level of the divided output voltages from the voltage dividing means; control means for receiving and processing signals from the overcharge voltage detection means and overdischarge voltage detection means and for outputting a signal for controlling the charge/discharge of the secondary cell; and activating means connected in series with the voltage dividing means for activating the voltage dividing means so as to limit the power consumption of the charge/discharge control circuit.
Claim 5
Dependent Claim
105 words
A charge/discharge control circuit comprising: voltage dividing means for dividing a voltage of an electric power source and producing a plurality of divided output voltages; overcharge voltage detection means and overdischarge voltage detection means for detecting a level of the divided output voltages from the voltage dividing means; control means for receiving and processing a signal from the overcharge voltage detection means and overdischarge voltage detection means and for outputting a signal for controlling the charge/discharge of the electric power source; and current limiting means controlled by the control means for limiting the current drain by the charge/discharge control circuit on the electric power source.
Claim 6
Dependent Claim
105 words
A charge/discharge control circuit comprising: voltage dividing means for dividing a voltage of an electric power source and producing a plurality of divided output voltages; overcharge voltage detection means and overdischarge voltage detection means for detecting a level of the divided output voltages from the voltage dividing means; control means for receiving and processing a signal from the overcharge voltage detection means and overdischarge voltage detection means and for outputting a signal for controlling the charge/discharge of the electric power source; and current limiting means controlled by the control means for limiting the current drain by the charge/discharge control circuit on the electric power source.
Claim 7
Dependent Claim
125 words
A chargeable electric power source apparatus having a secondary cell connected through a switching means from an external electric power source terminal, a charge/discharge control circuit connected in parallel to the secondary cell for controlling the switching means, and current limiting means for limiting the power consumption of the charge/discharge control circuit, the charge/discharge control circuit comprising: voltage dividing means for dividing a voltage of the secondary cell and producing a plurality of divided output voltages; overcharge voltage detection means and overdischarge voltage detection means for detecting a level of the divided output voltages from the voltage dividing means; and control means for receiving and processing a signal from the overcharge voltage detection means and overdischarge voltage detection means and for controlling the switching means.
Claim 8
Dependent Claim
125 words
A chargeable electric power source apparatus having a secondary cell connected through a switching means from an external electric power source terminal, a charge/discharge control circuit connected in parallel to the secondary cell for controlling the switching means, and current limiting means for limiting the power consumption of the charge/discharge control circuit, the charge/discharge control circuit comprising: voltage dividing means for dividing a voltage of the secondary cell and producing a plurality of divided output voltages; overcharge voltage detection means and overdischarge voltage detection means for detecting a level of the divided output voltages from the voltage dividing means; and control means for receiving and processing a signal from the overcharge voltage detection means and overdischarge voltage detection means and for controlling the switching means.
Claim 9
Dependent Claim
79 words
A charge/discharge control circuit comprising: voltage dividing means for dividing an electric power source voltage and producing a plurality of divided output voltages; voltage detection means for detecting a level of the divided output voltages of the voltage dividing means; delay means for delaying an output signal of the voltage detection means; and control means for receiving and processing a signal from the delay means and for outputting a signal for controlling the charge/discharge of the electric power source.
Claim 10
Dependent Claim
79 words
A charge/discharge control circuit comprising: voltage dividing means for dividing an electric power source voltage and producing a plurality of divided output voltages; voltage detection means for detecting a level of the divided output voltages of the voltage dividing means; delay means for delaying an output signal of the voltage detection means; and control means for receiving and processing a signal from the delay means and for outputting a signal for controlling the charge/discharge of the electric power source.
Claim 11
Dependent Claim
107 words
A chargeable electric power source apparatus having a secondary cell connected through a switching means from an external electric power source terminal, and a charge/discharge control circuit connected in parallel to the secondary cell for controlling the switching means, the charge/discharge control circuit comprising: voltage detection means for detecting a level of a charge/discharge voltage of the secondary cell and producing an output signal; delay means for delaying the output signal of the voltage detection means; and control means for receiving and processing a delayed output signal from the delay means and for outputting a signal for controlling the charge/discharge of the secondary cell in accordance therewith.
Claim 12
Dependent Claim
107 words
A chargeable electric power source apparatus having a secondary cell connected through a switching means from an external electric power source terminal, and a charge/discharge control circuit connected in parallel to the secondary cell for controlling the switching means, the charge/discharge control circuit comprising: voltage detection means for detecting a level of a charge/discharge voltage of the secondary cell and producing an output signal; delay means for delaying the output signal of the voltage detection means; and control means for receiving and processing a delayed output signal from the delay means and for outputting a signal for controlling the charge/discharge of the secondary cell in accordance therewith.
Claim 13
Dependent Claim
166 words
A chargeable electric power source comprising: external connection terminals; switch means connected to at least one of the external connection terminals; a secondary cell connected to the external connection terminals through the switch means; charge/discharge control means connected to the secondary cell for controlling the switch means; and current limiting means for limiting current consumption of the charge/discharge control means; wherein the charge/discharge control means comprises voltage dividing means for dividing a voltage of the secondary cell and producing a plurality of divided output voltages, overcharge detection means for receiving a divided output voltage, detecting an overcharge condition of the secondary cell, and producing a corresponding overcharge output signal, overdischarge detection means for receiving a divided output voltage, detecting an overdischarge condition of the secondary cell, and producing a corresponding overdischarge output signal, and control means for receiving and processing the overcharge output signal and the overdischarge output signal and generating a control output signal for controlling the charging and discharge operations of the secondary cell.
Claim 14
Dependent Claim
166 words
A chargeable electric power source comprising: external connection terminals; switch means connected to at least one of the external connection terminals; a secondary cell connected to the external connection terminals through the switch means; charge/discharge control means connected to the secondary cell for controlling the switch means; and current limiting means for limiting current consumption of the charge/discharge control means; wherein the charge/discharge control means comprises voltage dividing means for dividing a voltage of the secondary cell and producing a plurality of divided output voltages, overcharge detection means for receiving a divided output voltage, detecting an overcharge condition of the secondary cell, and producing a corresponding overcharge output signal, overdischarge detection means for receiving a divided output voltage, detecting an overdischarge condition of the secondary cell, and producing a corresponding overdischarge output signal, and control means for receiving and processing the overcharge output signal and the overdischarge output signal and generating a control output signal for controlling the charging and discharge operations of the secondary cell.
Claim 15
Dependent Claim
54 words
A chargeable electric power source according to claim 7; wherein the overcharge detection means and the overdischarge detection means each comprise a comparator for comparing a reference voltage set relative to a voltage level at a respective one of the external connection terminals and a respective divided output voltage from the voltage dividing means.
Claim 16
Dependent Claim
43 words
A chargeable electric power source according to claim 7; wherein the switch means includes means for receiving the control output signal and disconnecting the secondary cell from the external connection terminals upon detection of an overcharge or overdischarge condition of the secondary cell.
Claim 17
Dependent Claim
62 words
A chargeable electric power source according to claim 7; wherein the current limiting means comprises a switching element connected in series with the voltage dividing means and being receptive of an output signal from the charge/discharge control means for disconnecting the voltage dividing means from the secondary cell in response to detection of an overcharge or overdischarge condition of the secondary cell.
Claim 18
Dependent Claim
45 words
A chargeable electric power source according to claim 10; wherein the voltage dividing means comprises a plurality of resistance elements, and wherein an ON resistance of the switching element is less than a resistance value of the respective resistance elements of the voltage dividing means.
Claim 19
Dependent Claim
34 words
A chargeable electric power source according to claim 10; wherein the switching element comprises at least one insulated gate field effect transistor disposed between a respective external connection terminal and the voltage dividing means.
Claim 20
Dependent Claim
82 words
A chargeable electric power source according to claim 7; wherein the overcharge detection means comprises an error amplifier for detecting a difference between a respective divided output voltage of the voltage dividing means and a reference voltage, the error amplifier having a power source input connected to an output of the overdischarge detection means such that the error amplifier of the overcharge detection means is turned off when an overdischarge condition of the secondary cell is detected by the overdischarge detection means.
Claim 21
Dependent Claim
20 words
A chargeable electric power source according to claim 7; wherein the secondary cell comprises a plurality of series-connected secondary cells.
Claim 22
Dependent Claim
39 words
A chargeable electric power source according to claim 14; further comprising buffer means for receiving an intermediate voltage between respective series-connected secondary cells and producing an output signal in accordance with a relative charge state between the secondary cells.
Claim 23
Dependent Claim
21 words
A chargeable electric power source according to claim 7; wherein the voltage dividing means comprises a plurality of series-connected polycrystalline resistors.
Claim 24
Dependent Claim
142 words
A chargeable electric power source according to claim 7; wherein the voltage dividing means comprises three series-connected resistors connected in parallel with the secondary cell, the overcharge detection means comprises a first comparator for comparing a reference voltage and a first divided output voltage of the voltage dividing means, and the overdischarge detection means comprises a second comparator for comparing the reference voltage with a second divided output voltage of the voltage dividing means, such that an overcharge voltage V KAH of the secondary cell and an overdischarge voltage V KAJ of the secondary cell are defined by the following equations V.sub.KAH =(R.sub.1 +R.sub.2 +R.sub.3)×V.sub.REF /(R.sub.1 +R.sub.3) V.sub.KAJ =(R.sub.1 +R.sub.2 +R.sub.3)×V.sub.REF /R.sub.3 wherein R 1 , R 2 , and R 3 are resistance values of the three resistors of the voltage dividing means and V REF is the reference voltage level.
Claim 25
Dependent Claim
118 words
A chargeable electric power source according to claim 7; wherein the secondary cell comprises first and second series-connected secondary cells, the voltage dividing means comprises a first voltage dividing circuit connected in parallel with the first secondary cell and a second voltage dividing circuit connected in parallel with the second secondary cell, the overcharge detection means comprises a first overcharge detection circuit for detecting an overcharge condition of the first secondary cell and a second overcharge detection circuit for detecting an overcharge condition of the second secondary cell, and the overdischarge detection means comprises a first overdischarge detecting circuit for detecting an overdischarge condition of the first secondary cell and an overdischarge condition of the second secondary cell.
Claim 26
Dependent Claim
42 words
A chargeable electric power source according to claim 18; further comprising buffer means for receiving an intermediate voltage between the first and second secondary cells and producing an output voltage representative of a balance condition between the first and second secondary cells.
Claim 27
Dependent Claim
74 words
A chargeable electric power source according to claim 19; wherein the buffer means comprises an arithmetic circuit for receiving the intermediate voltage between the first and second secondary cells and producing the output voltage; and the current limiting means comprises a switching element for cutting off a current supply to the arithmetic circuit upon detection of an overdischarge condition of a respective secondary cell to reduce power consumption of the chargeable electric power source.
Claim 28
Dependent Claim
33 words
A chargeable electric power source according to claim 7; further comprising a reference voltage generator for generating a single reference voltage for input to the overcharge detection means and the overdischarge detection means.
Claim 29
Dependent Claim
56 words
A chargeable electric power source according to claim 21; wherein the reference voltage generator comprises an enhancement mode field effect transistor and a series-connected depletion mode field effect transistor, the series-connected transistors being connected in parallel to the secondary cell, having coupled gates, and producing a reference voltage in accordance with a threshold potential difference therebetween.
Claim 30
Dependent Claim
66 words
A chargeable electric power source according to claim 22; wherein the secondary cell comprises first and second secondary cells, and the reference voltage generator comprises a plurality of series-connected enhancement mode field effect transistors and a series-connected depletion mode transistor, the series-connected transistors being connected in parallel with the secondary cell and producing a pair of reference voltages in accordance with a threshold potential difference therebetween.
Claim 31
Dependent Claim
37 words
A chargeable electric power source according to claim 7; further comprising means for stabilizing an output of the overcharge detection means due to variations in the potential of the secondary cell due to the internal resistance thereof.
Claim 32
Dependent Claim
37 words
A chargeable electric power source according to claim 24; wherein the means for stabilizing comprises a switching element connected in series with the voltage dividing means for increasing a divided voltage input to the overcharge detection means.
Claim 33
Dependent Claim
29 words
A chargeable electric power source according to claim 7; further comprising time delay generating means disposed between the overcharge detection means, the overdischarge detection means and the control means.
Claim 34
Dependent Claim
112 words
A chargeable electric power source according to claim 7; further comprising reference voltage generating means powered by the secondary cell for generating a reference voltage, and wherein the voltage dividing means comprises a plurality of resistor elements for producing a plurality of divided output voltages, the overcharge detection means and the overdischarge detection means comprise error amplifying means for receiving the plurality of divided output voltages from the voltage dividing means and for generating a plurality of output voltages in accordance with a difference between the reference voltage and the plurality of divided output voltages, and wherein the current limiting means comprises means for limiting a current through the error amplifying means.
Claim 35
Dependent Claim
36 words
A chargeable electric power source according to claim 27; wherein the error amplifying means comprises a multi-input error amplifier, and the current limiting means comprises a current limiting transistor connected in series with the error amplifier.
Claim 36
Dependent Claim
67 words
A chargeable electric power source according to claim 27; wherein the error amplifying means comprises a plurality of error amplifiers, each for receiving the reference voltage and a respective one of the plurality of divided voltages, and the current limiting means comprises a circuit for controlling at least one of the plurality of error amplifiers in accordance with an output of another one of the error amplifiers.
Claim 37
Dependent Claim
55 words
A chargeable electric power source according to claim 27; wherein the error amplifying means comprises a plurality of error amplifiers, each for receiving the reference voltage and a respective one of the plurality of divided voltages, and the current limiting means comprises a current limiting transistor connected in series with the plurality of error amplifiers.
Claim 38
Dependent Claim
30 words
A chargeable electric power source according to claim 7; wherein the charge/discharge control means further comprises means for resetting the overcharge detection means by feeding back the output signal thereof.
Claim 39
Dependent Claim
32 words
A chargeable electric power source according to claim 7; wherein the charge/discharge control means further comprises delay means for delaying output signals of the overcharge detection means and the overdischarge detection means.
Claim 40
Dependent Claim
35 words
A chargeable electric power source according to claim 7; wherein the control means further comprises means for detecting a reversed polarity connection of an external power supply and disconnecting the switch means in response thereto.
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) | 2001-04-20 | 2001-10-20 | 2002-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-04-20 | 2005-10-20 | 2006-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-04-20 | 2009-10-20 | 2010-04-21 | $7700.00 | Window Closed / Lapsed |