US5477124A
Expired / Lapsed
US
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Circuit to prevent excessive rechargeable battery discharge
Assignee: Sanyo Electric Co Ltd
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Filing: 1994-08-04
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Granted: 1995-12-19
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Expires: 2014-08-04
Abstract
Abstract A circuit effectively prevents excessive discharge of a rechargeable battery that is either detachable from, or internal to an electrical apparatus. The circuit has a battery voltage detector, a comparitor to compare the battery voltage with a reference voltage, and a controller to cut-off power drain from a discharged battery when its voltage drops below the reference voltage. The discharged battery is electrically cut-off from both the load and the comparitor.
Inventors
- 👤 Mikitaka Tamai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 03:58
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/42; H01M10/44; H02; H02H; H02H7/00; H02H7/18; H02J; H02J7/00; H02J7/60; H02J7/663; H02J7/63; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
137 words
A circuit for preventing excessive rechargeable battery discharge of a rechargeable battery that attaches to an electrical apparatus and drives a load, comprising: (a) a voltage detection means for measuring a voltage of the rechargeable battery; (b) a comparison means powered BY the rechargeable battery for comparing the voltage measured by the voltage detection means with a reference voltage and for issuing a detection signal when the battery voltage drops below the reference voltage; and (c) a control means for shutting off power from the rechargeable Battery to the load and to the comparison means in response to the detection signal; wherein the rechargeable battery is freely attachable to and detachable from the electrical apparatus, and wherein the control means automatically discontinues the shutting off of power when the rechargeable battery is detached from the electrical apparatus.
Claim 2
Dependent Claim
137 words
A circuit for preventing excessive rechargeable battery discharge of a rechargeable battery that attaches to an electrical apparatus and drives a load, comprising: (a) a voltage detection means for measuring a voltage of the rechargeable battery; (b) a comparison means powered BY the rechargeable battery for comparing the voltage measured by the voltage detection means with a reference voltage and for issuing a detection signal when the battery voltage drops below the reference voltage; and (c) a control means for shutting off power from the rechargeable Battery to the load and to the comparison means in response to the detection signal; wherein the rechargeable battery is freely attachable to and detachable from the electrical apparatus, and wherein the control means automatically discontinues the shutting off of power when the rechargeable battery is detached from the electrical apparatus.
Claim 3
Dependent Claim
53 words
A circuit for preventing excessive rechargeable battery discharge as recited in claim 1, wherein the comparison means is a comparator that compares the battery voltage measured by the voltage detection means with the reference voltage and issues a detection signal when the battery voltage becomes less than or equal to a prescribed value.
Claim 4
Dependent Claim
44 words
A circuit for preventing excessive rechargeable battery discharge as recited in claim 1, wherein the control means is provided with a first switch connected between the rechargeable battery and the load and a second switch connected between the rechargeable battery and the comparison means.
Claim 5
Dependent Claim
33 words
A circuit for preventing excessive rechargeable battery discharge as recited in claim 3, wherein the first switch of the control means is an n-channel MOSFET having a source, a drain, and a gate.
Claim 6
Dependent Claim
42 words
A circuit for preventing excessive rechargeable battery discharge as recited in claim 4, wherein the source of the MOSFET, which is the first switch, is connected to a negative terminal of the rechargeable battery and the drain is connected to the load.
Claim 7
Dependent Claim
33 words
A circuit for preventing excessive rechargeable battery discharge as recited in claim 3, wherein the second switch of the control means is a p-channel MOSFET having a source, a drain, and a gate.
Claim 8
Dependent Claim
33 words
A circuit for preventing excessive rechargeable battery discharge as recited in claim 6, wherein the gate of the MOSFET, which is the second switch, is connected to the drain of the first switch.
Claim 9
Dependent Claim
128 words
A circuit for preventing excessive rechargeable battery discharge of a rechargeable battery contained in an electrical apparatus and drives a load, comprising: (a) a voltage detection means for measuring a voltage of the rechargeable battery; (b) a comparison means powered by the rechargeable battery for comparing the voltage measured by the voltage detection means with a reference voltage and for issuing a detection signal when the battery voltage drops below the reference voltage; and (c) a control means for shutting off power from the rechargeable battery to the load and to the comparison means in response to the detection signal; wherein the rechargeable battery is contained within the electrical apparatus, and wherein the control means automatically discontinues the shutting off of power when the rechargeable battery is recharged.
Claim 10
Dependent Claim
128 words
A circuit for preventing excessive rechargeable battery discharge of a rechargeable battery contained in an electrical apparatus and drives a load, comprising: (a) a voltage detection means for measuring a voltage of the rechargeable battery; (b) a comparison means powered by the rechargeable battery for comparing the voltage measured by the voltage detection means with a reference voltage and for issuing a detection signal when the battery voltage drops below the reference voltage; and (c) a control means for shutting off power from the rechargeable battery to the load and to the comparison means in response to the detection signal; wherein the rechargeable battery is contained within the electrical apparatus, and wherein the control means automatically discontinues the shutting off of power when the rechargeable battery is recharged.
Claim 11
Dependent Claim
186 words
A circuit for preventing excessive rechargeable battery discharge of a rechargeable battery that attaches to an electrical apparatus and drives a load, comprising: (a) a voltage detection means for measuring a voltage of the rechargeable battery; (b) a comparison means powered by the rechargeable battery for comparing the voltage measured by the voltage detection means with a reference voltage and for issuing a detection signal when the battery voltage drops below the reference voltage; and (c) a control means for shutting off power from the rechargeable battery to the load and to the comparison means in response to the detection signal; wherein the control means is provided with a first switch connected between the rechargeable battery and the load and a second switch connected between the rechargeable battery and the comparison means; wherein the first switch of the control means is an n-channel MOSFET having a source, a drain, and a gate; wherein the control means is further provided with a capacitor, and the gate of the MOSFET, which is the first switch, is connected to a positive terminal of the rechargeable battery via the capacitor.
Claim 12
Dependent Claim
186 words
A circuit for preventing excessive rechargeable battery discharge of a rechargeable battery that attaches to an electrical apparatus and drives a load, comprising: (a) a voltage detection means for measuring a voltage of the rechargeable battery; (b) a comparison means powered by the rechargeable battery for comparing the voltage measured by the voltage detection means with a reference voltage and for issuing a detection signal when the battery voltage drops below the reference voltage; and (c) a control means for shutting off power from the rechargeable battery to the load and to the comparison means in response to the detection signal; wherein the control means is provided with a first switch connected between the rechargeable battery and the load and a second switch connected between the rechargeable battery and the comparison means; wherein the first switch of the control means is an n-channel MOSFET having a source, a drain, and a gate; wherein the control means is further provided with a capacitor, and the gate of the MOSFET, which is the first switch, is connected to a positive terminal of the rechargeable battery via the capacitor.
Claim 13
Dependent Claim
43 words
A circuit for preventing excessive rechargeable battery discharge as recited in claim 9, wherein the control means is provided with a third switch connected in parallel with the capacitor, which is connected to the gate of the first switch, to discharge the capacitor.
Claim 14
Dependent Claim
28 words
A circuit for preventing excessive rechargeable battery discharge as recited in claim 10, wherein the third switch is a MOSFET having a source, a drain, and a gate.
Claim 15
Dependent Claim
29 words
A circuit for preventing excessive rechargeable battery discharge as recited in claim 11, wherein the gate of the third switch is a reset input terminal for a resetting pulse.
References Cited (Backward Citations)
US3800207A
Cited
DE2732794A1
Cited
US4704542A
Cited
US5177426A
Cited
JPH0433271A
Cited
US5179337A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-12-18 | 1999-06-19 | 1999-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-12-18 | 2003-06-19 | 2003-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-12-18 | 2007-06-19 | 2007-12-19 | $7700.00 | Window Closed / Lapsed |