US3656004A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bipolar capacitor driver
Assignee: International Business Machines Corp
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Filing: 1970-09-28
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Granted: 1972-04-11
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Expires: 1990-09-28
Abstract
Abstract This specification discloses a bipolar driver which will charge a capacitive load to substantially the potential supplied to the driver. The driver includes two transistors that couple the load to a source of potential. One transistor is connected in shunt with the load while the other transistor is connected in series with the load and the source of potential. The shunt-connected transistor is used to discharge the capacitive load while the serially connected transistor is used to charge the capacitive load with charge from the source of potential. To allow the capacitive load to be charged to the full potential of the source, the driver includes circuitry which decouples the base of the serially connected transistor from the source of potential and drives the transistor with charge accumulated in the base-toemitter junction of the transistor so that the serially connected transistor will not be turned off until the potential across the capacitive load reaches the potential of the driving source.
Inventors
- 👤 Douglas W Kemerer
- 👤 Jehoshua N Pomeranz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 11:30
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/04; H03K17/042; H03K17/04213; H03K17/51; H03K17/56; H03K17/60; H03K17/602; H03K17/66; H03K17/665; H03K17/666
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
209 words
A bipolar driver for charging a capacitive load from a voltage source comprising: a. a first bipolar transistor with its collector-to-emitter path connected in shunt with the capacitive load; b. a second bipolar transistor with its collector-to-emitter path connected in series between the source and the capacitive load and having its emitter connected to the collector of the first transistor at the node of the capacitive load to be charged; c. discharge control means coupled to the base of the first bipolar transistor for turning on said first bipolar transistor to discharge said node of the capacitive load; and d. charge control means coupled to the base of the second bipolar transistor for supplying drive from the source to the base of said second bipolar transistor for turning on said second bipolar transistor to charge said node of the capacitive load, said charge control means including means for decoupling the base of the second transistor from the source of potential when the potential at said node approaches the potential at the base of the second bipolar transistor so that the base-toemitter junction capacitance of the second bipolar transistor supplies base drive to the second bipolar transistor to charge said node to substantially the full potential of said voltage source.
Claim 2
Dependent Claim
209 words
A bipolar driver for charging a capacitive load from a voltage source comprising: a. a first bipolar transistor with its collector-to-emitter path connected in shunt with the capacitive load; b. a second bipolar transistor with its collector-to-emitter path connected in series between the source and the capacitive load and having its emitter connected to the collector of the first transistor at the node of the capacitive load to be charged; c. discharge control means coupled to the base of the first bipolar transistor for turning on said first bipolar transistor to discharge said node of the capacitive load; and d. charge control means coupled to the base of the second bipolar transistor for supplying drive from the source to the base of said second bipolar transistor for turning on said second bipolar transistor to charge said node of the capacitive load, said charge control means including means for decoupling the base of the second transistor from the source of potential when the potential at said node approaches the potential at the base of the second bipolar transistor so that the base-toemitter junction capacitance of the second bipolar transistor supplies base drive to the second bipolar transistor to charge said node to substantially the full potential of said voltage source.
Claim 3
Dependent Claim
55 words
The bipolar driver of claim 1 wherein said charge control means includes a third bipolar transistor with its collector-to-emitter path connected between the base of the second bipolar transistor and a terminal of the source of potential in a Darlington connection and its base coupled through a resistor to the same terminal of voltage source.
Claim 4
Dependent Claim
43 words
The bipolar driver of claim 2 wherein the charging time constant for the circuit coupling the base of the third bipolar transistor to the source of potential is smaller than the time constant for charging the capacitive load through the second bipolar transistor.
Claim 5
Dependent Claim
50 words
The bipolar driver of claim 3 including a fourth bipolar transistor with its collector-to-emitter path connected between the bases of the third and first transistors whereby when said fourth transistor is on said first transistor is conducting and when said fourth transistor is off said third transistor is biased non-conducting.
Claim 6
Dependent Claim
48 words
The unipolar driver of claim 4 including a unidirectional current path means from said node to the base of said first bipolar transistor through said fourth bipolar transistor when said fourth bipolar transistor is conducting to supply base drive to the first bipolar transistor from said capacitive load.
Claim 7
Dependent Claim
48 words
The bipolar driver of claim 5 including a fifth bipolar transistor with its collector-to-emitter path connected between the base and emitter of said first bipolar transistor, said fifth bipolar transistor being on when said fourth bipolar transistor is on and off when said fourth bipolar transistor is on.
Claim 8
Dependent Claim
29 words
A bipolar driver of claim 6 including a differential amplifier whereby said third and fourth bipolar transistors are driven by outputs of the base outputs of said differential switch.
Claim 9
Dependent Claim
67 words
The bipolar driver of claim 7 including back-to-back diodes connected between the outputs of a differential amplifier and a third diode connecting the common terminals of the two back-to-back diodes to a reference level and a resistor coupling the common terminals of two back-to-back diodes to a voltage level other than the reference level whereby the outputs of the differential amplifier are limited at the reference level.
References Cited (Backward Citations)
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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) | 1975-04-11 | 1975-10-11 | 1976-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-11 | 1979-10-11 | 1980-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-11 | 1983-10-11 | 1984-04-11 | $7700.00 | Window Closed / Lapsed |