Voltage protection circuit for transistor voltage regulator

Claim 2

An electrical system comprising: an alternating-current generator having an output winding and a field winding, a bridge rectifier network having AC input terminals connected with said output winding and two direct-current output terminals, a battery, means connecting said battery directly across said output terminals of said bridge rectifier whereby said bridge rectifier supplies charging current to said battery, a plurality of auxiliary diodes connected with said output winding, said auxiliary diodes being connected with a third direct-current output terminal, said third direct-current output terminal and one of said two direct-current output terminals of said bridge rectifier forming field-energizing terminals, a voltage regulator including a first switching device having a pair of currentcarrying terminals and a pair of control terminals, means serially connecting said field winding and said current-carrying terminals of said first switching device across said fieldenergizing terminals, a first voltage-sensing circuit for said voltage regUlator, means including a voltage-sensing lead connected with a first terminal of said battery connecting said first voltage-sensing circuit across said battery, means coupling said first voltage-sensing circuit with said first switching device to control the conduction of said device as a function of the output voltage of said generator, a second voltage-sensing circuit for said voltage regulator, means connecting said second voltage-sensing circuit across said field-energizing terminals, means connecting said second voltage-sensing circuit with said first switching device, a second switching device connected with said second voltage-sensing circuit and said voltage-sensing lead operative to enable said second voltage-sensing circuit as a control for said regulator when said voltage-sensing lead is disconnected from said battery, said second switching device disabling said second voltage-sensing circuit as a control for said regulator when said voltage-sensing lead is connected to said battery and when said bridge rectifier is connected with said battery.

Claim 3

An electrical system comprising: an alternating-current generator having an output winding and a field winding, a bridge rectifier network having AC input terminals connected with said output winding and two direct-current output terminals, a battery, means connecting said battery directly across said output terminals of said bridge rectifier whereby said bridge rectifier supplies charging current to said battery, a plurality of auxiliary diodes connected with said output winding, said auxiliary diodes being connected with a third direct-current output terminal, said third direct-current output terminal and one of said two direct-current output terminals of said bridge rectifier forming field-energizing terminals, a voltage regulator including a first semiconductor-switching means having a pair of current-carrying terminals and a pair of control terminals, means serially connecting said field winding and said current-carrying terminals of said first semiconductor-switching means across said field-energizing terminals, a first voltage-sensing circuit for said voltage regulator, means including a voltage-sensing lead connected with a first terminal of said battery connecting said first voltage-sensing circuit across said battery, means including a first voltage-responsive device coupling said first voltage-sensing circuit with said first semiconductor-switching means to control the conduction of said first semiconductor-switching means as a function of the output voltage of said generator, a second voltage-sensing circuit for said voltage regulator, means connecting said second voltage-sensing circuit across said field-energizing terminals, means including a second voltage-responsive device coupling said second voltage-sensing circuit with said first semiconductor-switching means, a second semiconductor-switching means, means connecting said second semiconductor-switching means in shunt with at least a part of said second voltage-sensing circuit, and means connecting said voltage-sensing lead with said second semiconductor-switching means to control the conduction of said second semiconductor-switching means, said second semiconductor-switching means being conductive and reducing the control voltage applied to said second voltage-responsive device when said voltage-sensing lead is connected with said first terminal of said battery, said second semiconductor-switching means being nonconductive and enabling said second voltage-sensing circuit to apply a voltage to said second voltage-responsive device to control said regulator when said voltage-sensing lead is disconnected from said battery.

Claim 4

An electrical system comprising: an alternating-current generator having an output winding and a field winding, a bridge rectifier network having AC input terminals connected with said output winding and two direct-current output terminals, a battery, means connecting said battery directly across said output terminals of said bridge rectifier whereby said bridge rectifier supplies charging current to said battery, a plurality of auxiliary diodes connected with said output winding, said auxiliary diodes being connected with a third direct-current output terminal, said third direct-current output terminal and one of said two direct-current output terminals of said bridge rectifier forming field-energizing terminals, a voltage regulator including a first semiconductor-switching means having a pair of current-carrying terminals and a pair of control terminals, means serially connecting said field winding and said current-carrying terminals of said first semiconductor-switching means across said field-energizing terminals, a first voltage-sensing circuit for said voltage regulator, means including a voltage-sensing lead connected with a first terminal of said battery connecting said first voltage-sensing circuit across said battery, means including a first voltage-responsive device coupling said first voltage-sensing circuit with said first semiconductor-switching means to control the conduction of said first semiconductor-switching means as a function of the output voltage of said generator, a second voltage-sensing circuit for said voltage regulator, means connecting said second voltage-sensing circuit across said field-energizing terminals, means including a second voltage-responsive device coupling said second voltage-sensing circuit with said first semiconductor-switching means, a second semiconductor-switching means, means connecting said second semiconductor-switching means in shunt with at least a part of said second voltage-sensing circuit, and means connecting said voltage-sensing lead with said second semiconductor-switching means to control the conduction of said second semiconductor-switching means, said second semiconductor-switching means being conductive and reducing the control voltage applied to said second voltage-responsive device when said voltage-sensing lead is connected with said first terminal of said battery, said second semiconductor-switching means being nonconductive and enabling said second voltage-sensing circuit to apply a voltage to said second voltage-responsive device to control said regulator when said voltage-sensing lead is disconnected from said battery.

Claim 5

An electrical system comprising: an alternating-current generator having an output winding and a field winding, a bridge rectifier network having AC input terminals connected with said output winding and two direct-current output terminals, a battery, means connecting said battery directly across said output terminalS of said bridge rectifier whereby said bridge rectifier supplies charging current to said battery, a plurality of auxiliary diodes connected with said output winding, said auxiliary diodes being connected with a third direct-current output terminal, said third direct-current output terminal and one of said two direct-current output terminals of said bridge rectifier forming field-energizing terminals, a voltage regulator including a first transistor switching means having collector-emitter current-carrying terminals and base-emitter control terminals, means serially connecting said field winding and said current-carrying terminals of said first transistor switching means across said field-energizing terminals, a first voltage-sensing circuit for said voltage regulator, means including a voltage-sensing lead connected with a first terminal of said battery connecting said first voltage-sensing circuit across said battery, a transistor driver means having collector-emitter current-carrying and base-emitter control terminals, said current-carrying terminals of said driver means being connected with said control terminals of said first transistor-switching means to render said first transistor-switching means conductive when said driver means is nonconductive and to render said first transistor-switching means nonconductive when said driver means is conductive, a first Zener diode, means connecting said first Zener diode between said first voltage-sensing circuit and one control terminal of said transistor driver means, a second voltage-sensing circuit for said voltage regulator, means connecting said second voltage-sensing circuit across said field-energizing terminals, a second Zener diode, means connecting said second Zener diode between said second voltage-sensing circuit and one control terminal of said transistor driver means, a second transistor-switching means having collector-emitter current-carrying terminals and base-emitter control terminals, means connecting said second transistor-switching means in shunt with at least a part of said second voltage-sensing circuit, and means coupling said voltage-sensing lead with the base-emitter control terminals of said second transistor-switching means to control the conduction of said second transistor-switching means, said second transistor-switching means being biased conductive and operative to reduce the voltage applied by said second voltage-sensing circuit to said second Zener diode and the control terminals of said driver transistor means to a value which is not sufficient to bias said driver transistor means conductive when said voltage-sensing lead is connected with said first terminal of said battery and when said bridge rectifier is connected with said battery, said second transistor-switching means being nonconductive and enabling said second voltage-sensing circuit as a control for said regulator when said voltage-sensing lead is disconnected from said battery.

Claim 6

An electrical system comprising: an alternating-current generator having an output winding and a field winding, a bridge rectifier network having AC input terminals connected with said output winding and two direct-current output terminals, a battery, means connecting said battery directly across said output terminalS of said bridge rectifier whereby said bridge rectifier supplies charging current to said battery, a plurality of auxiliary diodes connected with said output winding, said auxiliary diodes being connected with a third direct-current output terminal, said third direct-current output terminal and one of said two direct-current output terminals of said bridge rectifier forming field-energizing terminals, a voltage regulator including a first transistor switching means having collector-emitter current-carrying terminals and base-emitter control terminals, means serially connecting said field winding and said current-carrying terminals of said first transistor switching means across said field-energizing terminals, a first voltage-sensing circuit for said voltage regulator, means including a voltage-sensing lead connected with a first terminal of said battery connecting said first voltage-sensing circuit across said battery, a transistor driver means having collector-emitter current-carrying and base-emitter control terminals, said current-carrying terminals of said driver means being connected with said control terminals of said first transistor-switching means to render said first transistor-switching means conductive when said driver means is nonconductive and to render said first transistor-switching means nonconductive when said driver means is conductive, a first Zener diode, means connecting said first Zener diode between said first voltage-sensing circuit and one control terminal of said transistor driver means, a second voltage-sensing circuit for said voltage regulator, means connecting said second voltage-sensing circuit across said field-energizing terminals, a second Zener diode, means connecting said second Zener diode between said second voltage-sensing circuit and one control terminal of said transistor driver means, a second transistor-switching means having collector-emitter current-carrying terminals and base-emitter control terminals, means connecting said second transistor-switching means in shunt with at least a part of said second voltage-sensing circuit, and means coupling said voltage-sensing lead with the base-emitter control terminals of said second transistor-switching means to control the conduction of said second transistor-switching means, said second transistor-switching means being biased conductive and operative to reduce the voltage applied by said second voltage-sensing circuit to said second Zener diode and the control terminals of said driver transistor means to a value which is not sufficient to bias said driver transistor means conductive when said voltage-sensing lead is connected with said first terminal of said battery and when said bridge rectifier is connected with said battery, said second transistor-switching means being nonconductive and enabling said second voltage-sensing circuit as a control for said regulator when said voltage-sensing lead is disconnected from said battery.

Claim 7

An electrical system comprising: an alternating-current generator having an output winding and a field winding, a bridge rectifier network having AC input terminals connected with said output winding and direct-current output terminals, a battery, means connecting said battery across said output terminals of said bridge rectifier, a plurality of auxiliary diodes connected with said output winding, said auxiliary diodes being connected with a third direct-current terminal, said third direct-current output terminal and one of said two direct-current output terminals of said bridge rectifier forming field-energizing terminals, a voltage regulator having a field-current control means, means connecting said field winding and said field-current control means in series across said field energizing terminals, a first voltage-developing circuit, means including a voltage-sensing lead connecting said first voltage-developing circuit across said battery, means coupling said first voltage-developing circuit and said field-current control means whereby Said field-current control means is controlled as a function of the voltage developed across said first voltage-developing circuit, a second voltage-developing circuit connected across said field-energizing terminals, means coupling a point on said second voltage-developing circuit and said field-current control means whereby said field-current control means can be controlled by the voltage developed at said point on said second voltage-developing circuit means, and control means connected with said second voltage-developing circuit and said voltage-sensing lead for controlling the magnitude of the voltage developed at said point on said second voltage-developing circuit, said control means providing a voltage at said point on said second voltage-developing circuit which has a value which is not sufficient to control the operation of said field-current control means when said voltage-sensing lead is connected to one side of said battery and when said bridge rectifier is connected with said battery, said control means operative to cause the voltage at said point to rise to a value such that it is capable of controlling said field-current control means when said voltage-sensing lead is disconnected from one side of said battery to disconnect said first voltage-developing circuit from said battery.

Claim 8

An electrical system comprising: an alternating-current generator having an output winding and a field winding, a bridge rectifier network having AC input terminals connected with said output winding and direct-current output terminals, a battery, means connecting said battery across said output terminals of said bridge rectifier, a plurality of auxiliary diodes connected with said output winding, said auxiliary diodes being connected with a third direct-current terminal, said third direct-current output terminal and one of said two direct-current output terminals of said bridge rectifier forming field-energizing terminals, a voltage regulator having a field-current control means, means connecting said field winding and said field-current control means in series across said field energizing terminals, a first voltage-developing circuit, means including a voltage-sensing lead connecting said first voltage-developing circuit across said battery, means coupling said first voltage-developing circuit and said field-current control means whereby Said field-current control means is controlled as a function of the voltage developed across said first voltage-developing circuit, a second voltage-developing circuit connected across said field-energizing terminals, means coupling a point on said second voltage-developing circuit and said field-current control means whereby said field-current control means can be controlled by the voltage developed at said point on said second voltage-developing circuit means, and control means connected with said second voltage-developing circuit and said voltage-sensing lead for controlling the magnitude of the voltage developed at said point on said second voltage-developing circuit, said control means providing a voltage at said point on said second voltage-developing circuit which has a value which is not sufficient to control the operation of said field-current control means when said voltage-sensing lead is connected to one side of said battery and when said bridge rectifier is connected with said battery, said control means operative to cause the voltage at said point to rise to a value such that it is capable of controlling said field-current control means when said voltage-sensing lead is disconnected from one side of said battery to disconnect said first voltage-developing circuit from said battery.

Claim 9

A voltage regulator for regulating the output voltage of a diode-rectified alternating-current generator operative to supply charging current to a battery in an automotive electrical system and having a field-winding comprising: field-energizing terminals adapted to be connected with direct-voltage output terminals of said alternating-current generator, a first transistor-switching means having collector-emitter current-carrying terminals and base-emitter control terminals for controlling conduction between said current-carrying terminals, said current-carrying terminals being adapted to be connected with the field winding of said alternating-current generator serially across said field-energizing terminals, a first voltage-sensing circuit for said voltage regulator, a voltage-sensing lead adapted to be connected with a first terminal of said battery for connecting said first voltage-sensing circuit across said battery, a transistor driver means having collector-emitter current-carrying terminals and base-emitter control terminals, said current-carrying terminals of said driver means being connected with said control terminals of said first transistor-switching means to render said first transistor-switching means conductive when said driver means is nonconductive and to render said first transistor-switching means nonconductive when said driver means is conductive, a first Zener diode connected between said first voltage-sensing circuit and a control terminal of said transistor driver means, a second voltage-sensing circuit for said voltage regulator, means connecting said second voltage-sensing circuit across said field-energizing terminals, a second Zener diode connected between said second voltage-sensing circuit and a control terminal of said transistor driver means, a second transistor-switching means having collector-emitter current-carrying terminals and base-emitter control terminals, means connecting said second transistor-switching means in shunt with at least a part of said second voltage-sensing circuit, and means coupling said voltage-sensing lead with the base-emitter control terminals of said second transistor-switching means to control the conduction of said second transistor-switching means, said second transistor-switching means being adapted to be biased conductive to reduce the voltage applied by said second voltage-sensing circuit to said second Zener diode and to the base-emitter control terminals of said transistor driver means to a value which is not sufficient to bias said transistor driver means conductive when said voltage-sensing lead is connected with said first terminal of said battery and said generator is connected with said battery, said Second transistor-switching means being nonconductive and enabling said second voltage-sensing circuit as a control for said regulator when said voltage-sensing lead is disconnected from said battery.

Claim 10

A voltage regulator for regulating the output voltage of a diode-rectified alternating-current generator operative to supply charging current to a battery in an automotive electrical system and having a field-winding comprising: field-energizing terminals adapted to be connected with direct-voltage output terminals of said alternating-current generator, a first transistor-switching means having collector-emitter current-carrying terminals and base-emitter control terminals for controlling conduction between said current-carrying terminals, said current-carrying terminals being adapted to be connected with the field winding of said alternating-current generator serially across said field-energizing terminals, a first voltage-sensing circuit for said voltage regulator, a voltage-sensing lead adapted to be connected with a first terminal of said battery for connecting said first voltage-sensing circuit across said battery, a transistor driver means having collector-emitter current-carrying terminals and base-emitter control terminals, said current-carrying terminals of said driver means being connected with said control terminals of said first transistor-switching means to render said first transistor-switching means conductive when said driver means is nonconductive and to render said first transistor-switching means nonconductive when said driver means is conductive, a first Zener diode connected between said first voltage-sensing circuit and a control terminal of said transistor driver means, a second voltage-sensing circuit for said voltage regulator, means connecting said second voltage-sensing circuit across said field-energizing terminals, a second Zener diode connected between said second voltage-sensing circuit and a control terminal of said transistor driver means, a second transistor-switching means having collector-emitter current-carrying terminals and base-emitter control terminals, means connecting said second transistor-switching means in shunt with at least a part of said second voltage-sensing circuit, and means coupling said voltage-sensing lead with the base-emitter control terminals of said second transistor-switching means to control the conduction of said second transistor-switching means, said second transistor-switching means being adapted to be biased conductive to reduce the voltage applied by said second voltage-sensing circuit to said second Zener diode and to the base-emitter control terminals of said transistor driver means to a value which is not sufficient to bias said transistor driver means conductive when said voltage-sensing lead is connected with said first terminal of said battery and said generator is connected with said battery, said Second transistor-switching means being nonconductive and enabling said second voltage-sensing circuit as a control for said regulator when said voltage-sensing lead is disconnected from said battery.