US4964010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for limiting a time integration value of a pulsed current
Assignee: Nihon Kohden Corp
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Filing: 1989-11-16
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Granted: 1990-10-16
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Expires: 2009-11-16
Abstract
Abstract An electronic device including a circuit element to which a pulse current is applied, and a device for limiting the time integration value of current flowing in the circuit element, the device being connected in series to the circuit element, to prevent the circuit element from being overheated.
Inventors
- 👤 Katsuyuki Miyasaka
- 👤 Takuo Aoyagi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 13:24
CPC Classifications
H; H05; H05B; H05B45/00; H05B45/50; H05B45/56; H05B45/30; H05B45/395; Y; Y02; Y02B; Y02B20/00; Y02B20/30
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
148 words
An electronic device, comprising: a circuit element; means for supplying a pulse current to said circuit element; means for supplying a constant current to said circuit element when a time integration value of the pulse current exceeds a predetermined value; wherein said circuit element is a light emitting diode having an anode and a cathode; and wherein said pulse current supplying means and said constant current supplying means together comprise a constant voltage source, a capacitor connected between said constant voltage source and the anode of said light emitting diode, a transistor having a base, a collector and an emitter, the collector being connected to said light emitting diode, and drive means for supplying a drive pulse current to the base of said transistor, whereby said transistor becomes saturated when the time integrated value of the pulse current supplied to said light emitting diode exceeds the predetermined value.
Claim 2
Dependent Claim
148 words
An electronic device, comprising: a circuit element; means for supplying a pulse current to said circuit element; means for supplying a constant current to said circuit element when a time integration value of the pulse current exceeds a predetermined value; wherein said circuit element is a light emitting diode having an anode and a cathode; and wherein said pulse current supplying means and said constant current supplying means together comprise a constant voltage source, a capacitor connected between said constant voltage source and the anode of said light emitting diode, a transistor having a base, a collector and an emitter, the collector being connected to said light emitting diode, and drive means for supplying a drive pulse current to the base of said transistor, whereby said transistor becomes saturated when the time integrated value of the pulse current supplied to said light emitting diode exceeds the predetermined value.
Claim 3
Dependent Claim
18 words
The electronic device as defined in claim 1, further comprising a resistor connected in parallel with said capacitor.
Claim 4
Dependent Claim
37 words
The electronic device as defined in claim 1, wherein said drive means comprises a differential amplifier having a positive terminal for receiving a pulse input signal and a negative terminal connected to the emitter of said transistor.
Claim 5
Dependent Claim
138 words
An electronic device, comprising: a circuit element; means for supplying a pulse current to said circuit element; means for supplying a constant current to said circuit element when a time integration value of the pulse current exceeds a predetermined value; wherein said circuit element is a thermistor having first and second connection terminals; and wherein said supplying means comprises a constant voltage source, a capacitor connected between said constant voltage source and the first connection terminal of said thermistor, a transistor having a base, a collector and an emitter, the collector being connected to the second connection terminal of said thermistor, and drive means for supplying a pulse drive signal to the base of said transistor, whereby said transistor becomes saturated when the time integrated value of the pulse current supplied to said thermistor exceeds the predetermined value.
Claim 6
Dependent Claim
138 words
An electronic device, comprising: a circuit element; means for supplying a pulse current to said circuit element; means for supplying a constant current to said circuit element when a time integration value of the pulse current exceeds a predetermined value; wherein said circuit element is a thermistor having first and second connection terminals; and wherein said supplying means comprises a constant voltage source, a capacitor connected between said constant voltage source and the first connection terminal of said thermistor, a transistor having a base, a collector and an emitter, the collector being connected to the second connection terminal of said thermistor, and drive means for supplying a pulse drive signal to the base of said transistor, whereby said transistor becomes saturated when the time integrated value of the pulse current supplied to said thermistor exceeds the predetermined value.
Claim 7
Dependent Claim
123 words
An electronic device, comprising: an LED; a parallel circuit comprising a resistor and a capacitor connected in parallel with each other; a constant voltage source; a transistor for supplying a pulse current to said LED; and drive means for supplying a pulse current to the base of said transistor; said LED and said parallel circuit being connected in series with each other between said constant voltage source and said transistor; the voltage across said parallel circuit representing a time integration value of the pulse current, and the output of said transistor saturates when the time integrated value of the pulse current supplied to said LED exceeds a predetermined value, thereby limiting the current supplied to the transistor, and preventing said LED from over-heating.
Claim 8
Dependent Claim
123 words
An electronic device, comprising: an LED; a parallel circuit comprising a resistor and a capacitor connected in parallel with each other; a constant voltage source; a transistor for supplying a pulse current to said LED; and drive means for supplying a pulse current to the base of said transistor; said LED and said parallel circuit being connected in series with each other between said constant voltage source and said transistor; the voltage across said parallel circuit representing a time integration value of the pulse current, and the output of said transistor saturates when the time integrated value of the pulse current supplied to said LED exceeds a predetermined value, thereby limiting the current supplied to the transistor, and preventing said LED from over-heating.
Claim 9
Dependent Claim
37 words
An electronic device as claimed in claim 5, wherein said drive means comprises a differential amplifier having a positive terminal for receiving a pulse input signal, and a negative terminal connected to the emitter of said transistor.
Claim 10
Dependent Claim
115 words
An electronic device, comprising: a thermistor; a parallel circuit comprising a resistor and a capacitor connected in parallel with each other; a constant voltage source; a transistor for supplying a pulse current to said thermister; and drive means for supplying a drive pulse current to the base of said transistor; said thermistor and said parallel circuit being connected in series with each other between said constant voltage source and said transistor; the voltage across said parallel circuit representing a time integration value of the pulse current; the output of said transistor saturating when the time integrated value of the pulse current supplied to said thermistor exceeds a predetermined value, thereby preventing said thermistor from over-heating.
Claim 11
Dependent Claim
115 words
An electronic device, comprising: a thermistor; a parallel circuit comprising a resistor and a capacitor connected in parallel with each other; a constant voltage source; a transistor for supplying a pulse current to said thermister; and drive means for supplying a drive pulse current to the base of said transistor; said thermistor and said parallel circuit being connected in series with each other between said constant voltage source and said transistor; the voltage across said parallel circuit representing a time integration value of the pulse current; the output of said transistor saturating when the time integrated value of the pulse current supplied to said thermistor exceeds a predetermined value, thereby preventing said thermistor from over-heating.
Claim 12
Dependent Claim
37 words
An electronic device as claimed in claim 7, wherein said drive means comprises a differential amplifier having a positive terminal for receiving a pulse input signal and a negative terminal connected to the emitter of said transistor.
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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) | 1993-10-15 | 1994-04-16 | 1994-10-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-15 | 1998-04-16 | 1998-10-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-15 | 2002-04-16 | 2002-10-16 | $7700.00 | Window Closed / Lapsed |