Series voltage regulator with limited current consumption at low input voltages

Claim 2

A series voltage regulator comprising a normally non-saturated regulating transistor with its emitter-to-collector path arranged in a series arm of the regulator, the base of said regulating transistor being controlled via a control transistor by a first differential amplifier having first and second input ports, the first differential amplifier comparing a reference voltage which is supplied to the first input port with a voltage which is supplied to the second input port and which is proportional to the output voltage of the regulator, wherein the reference voltage supplied to the first input port of the first differential amplifier is controlled as a function of the difference between the input voltage and the output voltage of the series voltage regulator.

Claim 3

The series voltage regulator as in claim 1, wherein a differential circuit is provided which compares the collector-to-emitter voltage of the regulating transistor with an auxiliary voltage, the output of said differential circuit being followed by a limiting circuit which is connected to the first input port of the first differential amplifier, the auxiliary voltage being greater than the collector-to-emitter voltage of the regulating transistor which comes about at the beginning of the saturation state of the regulating transistor, and the limiting circuit decreasing a voltage delivered by a reference voltage source to the first input port of the first differential amplifier as soon as the differential circuit detects a decrease in the collector-to-emitter voltage of the regulating transistor to the auxiliary voltage.

Claim 4

The series voltage regulator as in claim 2, wherein the differential circuit includes a second differential amplifier, whose non-inverting input is connected with the collector of the regulating transistor and whose inverting input is connected to the emitter of the regulating transistor via an auxiliary voltage source which delivers the auxiliary voltage.

Claim 5

The series voltage regulator as in claim 2, wherein the limiting circuit includes a limiting transistor whose emitter-to-collector path is connected between the first input port of the first differential amplifier and the series arm of the series voltage regulator not provided with the regulating transistor and whose base is connected to the output of the differential circuit.

Claim 6

The series voltage regulator as in claim 2, wherein the base of the control transistor is connected to the output of the first differential amplifier, whose first input port is connected to the reference voltage source and whose seond input port is connected to a tapping point of a voltage divider connected in parallel to the output of the series voltage regulator.

Claim 7

The series voltage regulator as in claim 2, wherein the auxiliary voltage is formed by a constant voltage source.

Claim 8

The series voltage regulator as in claim 2, wherein the auxiliary voltage may be varied in accordance with the output current of the series voltage regulator.

Claim 9

The series voltage regulator as in claim 7, wherein the auxiliary voltage is composed of a constant primary voltage and a variable voltage superimposed on this primary voltage and proportional to the output current of the regulator.

Claim 10

The series voltage regulator as in claim 8, wherein the differential circuit includes a second differential amplifier, wherein the auxiliary voltage is delivered by an auxiliary voltage source which includes a resistor connected between the emitter of the regulating transistor and the inverting input of the second differential amplifier and wherein the connecting point between the resistor and the inverting input of the second differential amplifier is connected both to a constant current source generating the primary voltage and to a variable current source generating the variable voltage and whose current is proportional to the collector current of the regulating transistor.

Claim 11

The series voltage regulator as in claim 9, wherein the variable current source includes an auxiliary transistor whose emitter is connected to the emitter of the regulating transistor and whose base is connected to the base of the regulating transistor and whose collector yields a current proportional to the collector current of the regulating transistor, the emitter area of the auxiliary transistor and the emitter area of the regulating transistor being in a relation corresponding to the desired proportionality factor between their collector currents.

Claim 12

The series voltage regulator as in claim 10, wherein the collector of the auxiliary transistor is connected to the input side of a current mirror, whose output side is connected to the connecting point between the resistor and the inverting input of the second differential amplifier.

Claim 13

The series voltage regulator as in claim 11, wherein the collector of the auxiliary transistor is connected to the base of a transistor with its emitter-to-collector path connected in parallel to the constant current source, a diode being connected in parallel to its base-to-emitter path.

Claim 14

The series voltage regulator as in claim 9, wherein the regulating transistor is designed as a multi-transistor having a main collector connected to the output of the series voltage regulator, and an auxiliary collector yielding a current proportional to the main collector current, the main collector area and the auxiliary collector area being in a relation corresponding to the desired proportionality ratio between the main and auxiliary collector currents.

Claim 15

The series voltage regulator as in claim 13, wherein the auxiliary collector is connected to the input side of a current mirror, whose output side is connected to the connecting point between the resistor and the inverting input of the second differential amplifier.

Claim 16

The series voltage regulator as in claim 14, wherein the auxiliary collector is connected to the base of a transistor with its emitter-to-collector path connected in parallel to the constant current source, a diode being connected in parallel to its base-to-emitter path.

Claim 17

The series voltage regulator as in claim 9, wherein the variable current source includes an auxiliary transistor whose emitter is connected to the emitter of the regulating transistor and whose base is connected to the base of the regulating transistor and whose collector yields a current proportional to the collector current of the regulating transistor, the emitter area of the auxiliary transistor and the emitter area of the regulating transistor being in a relation corresponding to the desired proportionality factor between their collector currents, and wherein the collector of the auxiliary transistor is connected to the base of a transistor with its emitter-to-collector path connected in parallel to the constant current source, a diode being connected in parallel to its base-to-emitter path.

Claim 18

The series voltage regulator as in claim 16, wherein for at least some of the transistors, field-effect transistors are provided whose source, drain and gate electrodes replace the emitter, collector and base electrodes.

Claim 19

The series voltage regulator as in claim 9, wherein the regulating transistor is designed as a multi-transistor having a main collector connected to the output of the series voltage regulator, and an auxiliary collector yielding a current proportional to the main collector current, the main collector area and the auxiliary collector area being in a relation corresponding to the desired proportionality ratio between the main and auxiliary collector currents, and wherein the auxiliary collector is connected to the base of a transistor with its emitter-to-collector path connected in parallel to the constant current source, a diode being connected in parallel to its base-to-emitter path.

Claim 20

The series voltage regulator as in claim 18, wherein for at least some of the transistors, field-effect transistors are provided whose source, drain and gate electrodes replace the emitter, collector and base electrodes.

Claim 21

A series voltage regulator for transferring electric power from a battery to a load, comprising a normally non-saturated regulating transistor with its emitter-to-collector path arranged in a series arm of the regulator, the base of said regulating transistor being controlled via a control transistor by a first differential amplifier having first and second input ports, the first differential amplifier comparing a reference voltage which is supplied to the first input port with a voltage which is supplied to the second input port and which is proportional to the output voltage of the regulator, wherein the reference voltage supplied to the first input port of the first differential amplifier is controlled as a function of the difference between the input voltage and the output voltage of the series voltage regulator.

Claim 22

A series voltage regulator for transferring electric power from a battery to a load, comprising a normally non-saturated regulating transistor with its emitter-to-collector path arranged in a series arm of the regulator, the base of said regulating transistor being controlled via a control transistor by a first differential amplifier having first and second input ports, the first differential amplifier comparing a reference voltage which is supplied to the first input port with a voltage which is supplied to the second input port and which is proportional to the output voltage of the regulator, wherein the reference voltage supplied to the first input port of the first differential amplifier is controlled as a function of the difference between the input voltage and the output voltage of the series voltage regulator.

Claim 23

A series voltage regulator having first and second input ports for receiving electrical power from a power source and having first and second output ports for providing regulated electrical power to a load, comprising: a regulating transistor, the emitter-to-collector path of the regulating transistor being connected between the first input port of the regulator and the first output port of the regulator; voltage divider means, connected between the first and second output ports of the regulator, for generating a signal that is proportional to the voltage between the first and second output ports; a differential amplifier having first and second input ports and having an output port, the second input port of the differential amplifier receiving the signal that is proportional to the voltage between the first and second output ports of the regulator; a control transistor, the emitter-to-collector path of the control transistor being connected between the base of the regulating transistor and the second output port of the regulator, the base of the control transistor being connected to the output port of the differential amplifier; a reference voltage source; an impedance element connected between the reference voltage source and the first input port of the differential amplifier; means connected to the first input port of the differential amplifier for controlling the potential at the first input port of the differential amplifier as a function of the voltage between the collector and emitter of the regulator transistor; and means for connecting the second input port of the regulator to the second output port of the regulator.

Claim 24

A series voltage regulator having first and second input ports for receiving electrical power from a power source and having first and second output ports for providing regulated electrical power to a load, comprising: a regulating transistor, the emitter-to-collector path of the regulating transistor being connected between the first input port of the regulator and the first output port of the regulator; voltage divider means, connected between the first and second output ports of the regulator, for generating a signal that is proportional to the voltage between the first and second output ports; a differential amplifier having first and second input ports and having an output port, the second input port of the differential amplifier receiving the signal that is proportional to the voltage between the first and second output ports of the regulator; a control transistor, the emitter-to-collector path of the control transistor being connected between the base of the regulating transistor and the second output port of the regulator, the base of the control transistor being connected to the output port of the differential amplifier; a reference voltage source; an impedance element connected between the reference voltage source and the first input port of the differential amplifier; means connected to the first input port of the differential amplifier for controlling the potential at the first input port of the differential amplifier as a function of the voltage between the collector and emitter of the regulator transistor; and means for connecting the second input port of the regulator to the second output port of the regulator.