Switched amplification system having radiation compensation circuitry

Claim 2

An amplifier system comprising: first and second differential amplifiers each connected to receive different low level input signals, each of said amplifiers including transistor pairs receiving said input signals at the bases thereof and coupled together at the emitters in a differential configuration, a third differential amplifier having inputs connected to receive the outputs of each of said first and second amplifiers, electronic switching means coupled between the emitter of each of said first and second amplifiers and a power source for seLectively coupling them to said third differential amplifier, and said electronic switching means comprising a plurality of diode means connected in parallel and poled in the same direction across a voltage supply, the breakdown voltages of said diode means being approximately equal and said diode means being selectively operable in response to logic input signals such that either of said first or second amplifiers may be actuated to exclusively feed signals into said third amplifier.

Claim 3

An amplifier system comprising: first and second differential amplifiers each connected to receive different low level input signals, each of said amplifiers including transistor pairs receiving said input signals at the bases thereof and coupled together at the emitters in a differential configuration, a third differential amplifier having inputs connected to receive the outputs of each of said first and second amplifiers, electronic switching means coupled between the emitter of each of said first and second amplifiers and a power source for seLectively coupling them to said third differential amplifier, and said electronic switching means comprising a plurality of diode means connected in parallel and poled in the same direction across a voltage supply, the breakdown voltages of said diode means being approximately equal and said diode means being selectively operable in response to logic input signals such that either of said first or second amplifiers may be actuated to exclusively feed signals into said third amplifier.

Claim 4

An amplifier system comprising: first and second differential amplifiers each connected to receive different low level input signals, each of said amplifiers including transistor pairs receiving said input signals at the bases thereof and coupled together at the emitters in a differential configuration, a third differential amplifier having inputs connected to receive the outputs of each of said first and second amplifiers, electronic switching means coupled between the emitter of each of said first and second amplifiers and a power source for seLectively coupling them to said third differential amplifier, and said electronic switching means comprising a plurality of diode means connected in parallel and poled in the same direction across a voltage supply, the breakdown voltages of said diode means being approximately equal and said diode means being selectively operable in response to logic input signals such that either of said first or second amplifiers may be actuated to exclusively feed signals into said third amplifier.

Claim 5

An amplifier system comprising: first and second differential amplifiers each connected to receive different low level input signals, each of said amplifiers including transistor pairs receiving said input signals at the base thereof and coupled together at the emitters in a differential configuration, a third differential amplifier having inputs connected to receive the outputs of each of said first and second amplifiers, electronic switching devices coupled between the emitters of each of said first and second amplifiers and a power source, and diode means for selectively operating said switching devices in accordance with logic input signals such that either of said first or second amplifiers may be actuated to exclusively feed signals into said third amplifier, the breakdown voltages of each of said diode means being generally equal, and wherein said diode means comprises a first Zener diode connected through resistances to bias voltage, the voltage at the anode thereof maintaining each of said first and second amplifiers off when no logic input is received, and a second Zener diode connected to each of said electronic switching devices and each Zener diode operable in response to a high logic voltage at the cathode thereof to turn the respective amplifier stage on.

Claim 6

An amplifier system comprising: first and second differential amplifiers each connected to receive different low level input signals, each of said amplifiers including transistor pairs receiving said input signals at the base thereof and coupled together at the emitters in a differential configuration, a third differential amplifier having inputs connected to receive the outputs of each of said first and second amplifiers, electronic switching devices coupled between the emitters of each of said first and second amplifiers and a power source, and diode means for selectively operating said switching devices in accordance with logic input signals such that either of said first or second amplifiers may be actuated to exclusively feed signals into said third amplifier, the breakdown voltages of each of said diode means being generally equal, and wherein said diode means comprises a first Zener diode connected through resistances to bias voltage, the voltage at the anode thereof maintaining each of said first and second amplifiers off when no logic input is received, and a second Zener diode connected to each of said electronic switching devices and each Zener diode operable in response to a high logic voltage at the cathode thereof to turn the respective amplifier stage on.

Claim 7

An amplifier comprising: first and second differential amplifiers each connected to receive different low level input signals, each of said amplifiers including transistor pairs receiving said input signals at the bases thereof and coupled together at the emitters in a differential configuration, a third differential amplifier having inputs connected to receive the outputs of each of said first and second amplifiers, electronic switching devices coupled between the emitters of each of said first and second amplifiers and a power source, means for selectively operating said switching devices in accordance with logic input signals such that either of said first or second amplifiers may be actuated to exclusively feed signals into said third amplifier, and radiation compensation means comprising a transistor connected in an emitter follower configuration having its base electrode connected to the output of one transistor in said first differential amplifier and one transistor in said second differential amplifier, said transistor being in an emitter follower configuration and having its photocurrent collection volume approximately equal to the sum of the photocurrent collection volume of said one transistor in said first differential amplifier and said one transistor in said second differential amplifier.

Claim 8

An amplifier comprising: first and second differential amplifiers each connected to receive different low level input signals, each of said amplifiers including transistor pairs receiving said input signals at the bases thereof and coupled together at the emitters in a differential configuration, a third differential amplifier having inputs connected to receive the outputs of each of said first and second amplifiers, electronic switching devices coupled between the emitters of each of said first and second amplifiers and a power source, means for selectively operating said switching devices in accordance with logic input signals such that either of said first or second amplifiers may be actuated to exclusively feed signals into said third amplifier, and radiation compensation means comprising a transistor connected in an emitter follower configuration having its base electrode connected to the output of one transistor in said first differential amplifier and one transistor in said second differential amplifier, said transistor being in an emitter follower configuration and having its photocurrent collection volume approximately equal to the sum of the photocurrent collection volume of said one transistor in said first differential amplifier and said one transistor in said second differential amplifier.

Claim 9

In an amplifier system requiring switching of plural stages, the combination comprising: a first electronic switching device having Zener voltage breakdown characteristics and connected to a source of bias voltage through a resistance, one terminal of said first switching device connected to normally switch said stages out of said system; a second electronic switching device having Zener voltage breakdown characteristics approximately equal to the characteristics of said first device and connected through a resistance to said source of bias voltage, one terminal of said second switching device connected for selectively switching one of said stages into or out of said system, and unidirectional conducting means connected to the other terminal of said second switching device for receiving input logic signals which Selectively control the state of said second switching device.

Claim 10

In an amplifier system requiring switching of plural stages, the combination comprising: a first electronic switching device having Zener voltage breakdown characteristics and connected to a source of bias voltage through a resistance, one terminal of said first switching device connected to normally switch said stages out of said system; a second electronic switching device having Zener voltage breakdown characteristics approximately equal to the characteristics of said first device and connected through a resistance to said source of bias voltage, one terminal of said second switching device connected for selectively switching one of said stages into or out of said system, and unidirectional conducting means connected to the other terminal of said second switching device for receiving input logic signals which Selectively control the state of said second switching device.

Claim 11

The combination of claim 4 wherein said switching devices having Zener voltage breakdown characteristics comprise transistors having the bases and collectors commonly tied, and wherein the emitter-base breakdown characteristics of said transistors are generally equal.

Claim 12

The combination of claim 4 wherein said unidirectional conducting means comprises a transistor having the collector and base commonly connected with the emitter thereof and connected to receive the input logic signals.

Claim 13

The combination of claim 4 and further comprising: a third electronic switching device having Zener voltage breakdown characteristics and connected through a resistance to said source of bias voltage, one terminal of said third switching device connected for selectively switching another of said stages into or out of said system, and diode means connected to the other terminal of said third switching means for receiving logic signals which control the state of said third switching device.

Claim 14

The combination of claim 7 and further comprising: means connected to each of said switching devices for generating compensating current in response to the presence of radiation.

Claim 15

A radiation compensated amplification system comprising: a transistor amplification stage, and an active output stage connected to said amplification stage and including a transistor connected in an emitter follower configuration having its base electrode connected to the output of said amplification stage, said transistor having an emitter follower configuration having a photocurrent collection volume approximately equal to the photocurrent collection volume of the transistor in said amplification stage.

Claim 16

A radiation compensated amplification system comprising: a transistor amplification stage, and an active output stage connected to said amplification stage and including a transistor connected in an emitter follower configuration having its base electrode connected to the output of said amplification stage, said transistor having an emitter follower configuration having a photocurrent collection volume approximately equal to the photocurrent collection volume of the transistor in said amplification stage.

Claim 17

A differential amplifier circuit having radiation compensation comprising: a plurality of amplifying transistors connected to form a plurality of differential amplifiers, and at least two output transistors each connected in an emitter follower configuration and having their base electrodes connected to the output electrodes of a portion of said amplifying transistors, each said output transistor having a photocurrent collection volume generally equal to the sum of the photocurrent collection volumes of the amplifying transistors connected thereto.

Claim 18

A differential amplifier circuit having radiation compensation comprising: a plurality of amplifying transistors connected to form a plurality of differential amplifiers, and at least two output transistors each connected in an emitter follower configuration and having their base electrodes connected to the output electrodes of a portion of said amplifying transistors, each said output transistor having a photocurrent collection volume generally equal to the sum of the photocurrent collection volumes of the amplifying transistors connected thereto.

Claim 19

An amplifier system comprising: a differential amplifier having a plurality of transistors adapted to receive input signals at the base thereof and coupled together at the emitters in a differential configuration, electronic switching means coupled to said emitters of said transistors for selectively energizing said differential amplifier, said electronic switching means comprising a first device having Zener voltage breakdown characteristics connected to a source of bias voltage through a resistance, one terminal of said first device connected to normally disable said differential amplifier, a second device having Zener voltage breakdown characteristics approximately equal to said characteristics of said first device connected through a resistance to said source of bias voltage, one terminal of said second device connected for selectively enabling said differential amplifier, and uni-directional conducting means connected to the other terminal of said second device for receiving input logic signals which selectively control the state of said second device.

Claim 20

An amplifier system comprising: a differential amplifier having a plurality of transistors adapted to receive input signals at the base thereof and coupled together at the emitters in a differential configuration, electronic switching means coupled to said emitters of said transistors for selectively energizing said differential amplifier, said electronic switching means comprising a first device having Zener voltage breakdown characteristics connected to a source of bias voltage through a resistance, one terminal of said first device connected to normally disable said differential amplifier, a second device having Zener voltage breakdown characteristics approximately equal to said characteristics of said first device connected through a resistance to said source of bias voltage, one terminal of said second device connected for selectively enabling said differential amplifier, and uni-directional conducting means connected to the other terminal of said second device for receiving input logic signals which selectively control the state of said second device.

Claim 21

The combination of claim 11 wherein said switching devices having Zener voltage breakdown characteristics comprise transistors having the bases and collectors commonly tied, and wherein the emitter-base breakdown characteristics of said transistors are generally equal.

Claim 22

The combination of claim 11 wherein said unidirectional conducting means comprises a transistor having the collector and base commonly conducted with the emitter thereof and connected to receive the input logic signals.

Claim 23

The combination of claim 11 and further comprising: a third electronic switching device having Zener voltage breakdown characteristics and connected through a resistance to said source of bias voltage, one terminal of said third switching device connected for selectively switching another of said stages into or out of said system, and diode means connected to the other terminal of said third switching means for receiving logic signals which control the state of said third switching device.

Claim 24

The combination of claim 11 and further comprising: means connected to each of said switching devices for generating compensating current in response to the presence of radiation.