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US3602830A Expired / Lapsed US ⏱️ 0.0 years remaining

A constant current control circuit

Assignee: Honeywell Inc
•
Filing: 1969-10-21
•
Granted: 1971-08-31
•
Expires: 1989-10-21
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Abstract

Abstract There is disclosed a voltage (millivolts)-to-current transducer which transmits a current signal to a remote central station, which includes a power supply for a utilization device at the remote location, over a two-wire transmission line. The transmission line carries both the signal current from the transmitter to the remote station and the total power supply for the transmitter. A highly stable constant current source uses a field effect transistor as an element thereof. A variable resistor and temperature compensating diode are connected in series with the drain-source path of the field effect transistor and the gate of the field effect transistor is connected to the junction of a load and the diode. Further, a plural-stage amplifier has the DC power supply of the first amplifier stage of the plural stages isolated from the constant DC power supply of the following stages. The isolation is accomplished by means of a transistor having a constant voltage applied to the base thereof and having the constant DC power supply of the following stages applied to the collector thereof. The emitter is connected to the first amplifier stage to thereby supply the DC power supply thereto.

Inventors

  • 👤 Edward T E Hurd

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-03 07:15
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/38; H03F3/387; H03F3/393; G; G05; G05F; G05F1/00; G05F1/10; G05F1/46; G05F1/56; G05F1/565; G05F1/567; G08; G08C; G08C19/00; G08C19/02

Claims Analysis

Total Claims: 4
Claim 1
Independent Claim 90 words
A constant current control circuit means connected in series between a power supply source means and a load device, said circuit means comprising a field effect transistor having a pair of symmetrically conductive electrodes and a gate electrode, a resistor, said symmetrically conductive electrodes being serially connected between the power supply source means and said resistor, a temperature compensating diode connected in series between said resistor and said load device, and a connection from the junction between said load device and said diode to said gate electrode of said transistor.
Claim 2
Dependent Claim 90 words
A constant current control circuit means connected in series between a power supply source means and a load device, said circuit means comprising a field effect transistor having a pair of symmetrically conductive electrodes and a gate electrode, a resistor, said symmetrically conductive electrodes being serially connected between the power supply source means and said resistor, a temperature compensating diode connected in series between said resistor and said load device, and a connection from the junction between said load device and said diode to said gate electrode of said transistor.
Claim 3
Dependent Claim 163 words
In a plural-stage amplifier, a power supply system for said amplifier comprising a first supply lead, a reference lead, the plural stages of said plural-stage amplifier being connected to be energized between said first supply lead and said reference lead, dynamic isolation means for isolating the energization of a first portion of said plural stages from the energization of a second portion of said plural stages whereby to prevent spurious interaction between said first supply lead and said first portion of said plural stage, said second portion of said plural stages being connected directly to said first supply lead; said dynamic isolation means comprising a transistor having a base electrode, a collector electrode and an emitter electrode, constant voltage control means connected to apply a constant voltage bias signal at said base electrode, means including said first supply lead for applying a constant voltage bias at said collector electrode, and means connecting said first portion between said emitter electrode and said reference lead.
Claim 4
Dependent Claim 163 words
In a plural-stage amplifier, a power supply system for said amplifier comprising a first supply lead, a reference lead, the plural stages of said plural-stage amplifier being connected to be energized between said first supply lead and said reference lead, dynamic isolation means for isolating the energization of a first portion of said plural stages from the energization of a second portion of said plural stages whereby to prevent spurious interaction between said first supply lead and said first portion of said plural stage, said second portion of said plural stages being connected directly to said first supply lead; said dynamic isolation means comprising a transistor having a base electrode, a collector electrode and an emitter electrode, constant voltage control means connected to apply a constant voltage bias signal at said base electrode, means including said first supply lead for applying a constant voltage bias at said collector electrode, and means connecting said first portion between said emitter electrode and said reference lead.

References Cited (Backward Citations)

No citation records indexed.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1974-08-30 1975-03-01 1975-08-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1978-08-30 1979-03-01 1979-08-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1982-08-30 1983-03-01 1983-08-31 $7700.00 Window Closed / Lapsed

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