Collector follower-type transistorized voltage regulator with thermistor starting circuit

Claim 2

A voltage regulator for use between a power source and a load comprising: regulator transistor having an emitter, a base and a collector for controlling the voltage to be supplied to the load, said emitter being adapted to be connected to the power source; an output terminal connected to the collector and being adapted to be connected to said load; a voltage detecting means connected to the collector of said transistor for detecting a regulating signal proportional to the potential difference between the potential at said output terminal and a predetermined reference potential; an amplifier means connected between the base of said regulating transistor and said voltage detecting means for amplifying the regulating signal from said voltage detecting means and supplying the amplified regulating signal to said base as a controlling signal, whereby the conductance of said regulating transistor is controlled by said controlling signal; and a thermistor having a positive resistance-temperature coefficient connected between the base of said regulating transistor and a common reference potential, said thermistor having a low resistance in the starting moment of said regulating transistor and supplying a starting current to said transistor while having a high resistance sufficient to isolate said thermistor from the base of the regulator transistor in the normal operation of said regulator transistor.

Claim 3

In a voltage regulator for use between a power source and a load, including a regulator transistor having an emitter, a base and a collector for controlling the voltage to be supplied to the load, said emitter being adapted to be connected to the power source; an output terminal connected to the collector and being adapted to be connected to said load; first means connected to the collector of said transistor for detecting a regulating signal proportional to the potential difference between the potential at said output terminal and a predetermined reference potential; second means connected between the base of said regulating transistor and said voltage detecting means for amplifying the regulating signal from said voltage detecting means and supplying the amplified regulating signal to said base as a control signal, whereby the conductance of said regulating transistor is controlled by said controlling signal, the improvement comprising: third means comprising a thermistor, having a positive resistance-temperature coefficient, connected between the base of said regulator transistor and said predetermined reference potential, responsive to the transient flow of current through said regulator transistor, for supplying a starting current thereto when load current begins to flow and for providing a high resistance sufficient to isolate the base of said regulator transistor from said common reference potential during steady state load voltage at said output terminal.

Claim 4

In a voltage regulator for use between a power source and a load, including a regulator transistor having an emitter, a base and a collector for controlling the voltage to be supplied to the load, said emitter being adapted to be connected to the power source; an output terminal connected to the collector and being adapted to be connected to said load; first means connected to the collector of said transistor for detecting a regulating signal proportional to the potential difference between the potential at said output terminal and a predetermined reference potential; second means connected between the base of said regulating transistor and said voltage detecting means for amplifying the regulating signal from said voltage detecting means and supplying the amplified regulating signal to said base as a control signal, whereby the conductance of said regulating transistor is controlled by said controlling signal, the improvement comprising: third means comprising a thermistor, having a positive resistance-temperature coefficient, connected between the base of said regulator transistor and said predetermined reference potential, responsive to the transient flow of current through said regulator transistor, for supplying a starting current thereto when load current begins to flow and for providing a high resistance sufficient to isolate the base of said regulator transistor from said common reference potential during steady state load voltage at said output terminal.

Claim 5

A voltage regulator according to claim 2, wherein said first means comprises first and second voltage divider circuits connected in parallel across said load, said second means being connected to each of said first and second voltage divider elements.

Claim 6

A voltage regulator according to claim 3, wherein said first voltage divider circuit comprises a Zener diode in series with a first resistor, and said second voltage divider circuit comprises second and third resistors connected in series, said first means being connected to the common connection point of said Zener diode with said first resistor and the common connection point of said second and third resistors, respectively.

Claim 7

A voltage regulator according to claim 4, wherein said second means comprises an amplifying transistor having its electrodes respectively connected to the base of said regulator transistor and said common connection points of said first and second voltage dividers.

Claim 8

A voltage regulator according to claim 5, wherein said amplifying transistor has its base connected to the common connection point of said second and third resistors, its emitter connected to the common connection point of said Zener diode and said first resistor and its collector connected to the base of said regulator transistor.