Regulated power supply with start-up and protective circuits

Claim 2

A regulated power supply for producing a direct current voltage output in response to an alternating current input signal, including in combination: gated unidirectional conductive means operated in response to a gating signal and coupled to receive alternating current signals for producing direct current signals on an output terminal thereof; regulator means coupled with the output terminal of said unidirectional conductive means for regulating the magnitude of the direct current output voltage on said output terminal; timing control means for producing a time varying voltage; voltage responsive switch means coupled to sense the time varying voltage from said timing control means and coupled to supply gating signals to said gated unidirectional conductive means in response to a first predetermined voltage sensed thereby; and means coupled to sense current flow through said gated unidirectional conductive means and rendered operative thereby for clamping the voltage produced by said timing control means to a value less than said first predetermined voltage during the latter portion of the half-cycle of the alternating current input signal following conduction of said gated unidirectional conductive means and rendered inoperative when said gated unidirectional conductive means is rendered non-conductive upon commencement of the next succeeding half-cycle of the alternating current input signal, thereby establishing substantially the same starting voltage for said timing control means for each half-cycle of the input signal.

Claim 3

The combination according to claim 1 wherein said timing control means comprises a capacitor coupled with said output terminal through a charging path and charged at a rate proportional to the magnitude of the output voltage appearing on said output terminal, and said clamping means maintains the charge on said capacitor at a second predetermined voltage less than said first predetermined voltage.

Claim 4

The combination according to claim 2 further including supplementary means for supplying a starting charging current to said capacitor.

Claim 5

The combination according to claim 3 wherein said supplementary means comprises a supplementary rectifier circuit coupled to receive the alternating current input signal and the output of which is coupled in a charging path for said capacitor.

Claim 6

The combination according to claim 3 further including means coupled with said output terminal and responsive to the direct current voltage appearing thereon for substantially reducing the charging current supplied by said supplementary means to said capacitor in response to a third predetermined voltage appearing on said output terminal.

Claim 7

The combination according to claim 1 further including protection means coupled with said output terminal and further coupled with said timing control means for sensing the direct current voltage produced on said output terminal and responsive to voltages thereon exceeding a second predetermined voltage for preventing the voltage on said timing control means from attaining said first predetermined voltage.

Claim 8

The combination according to claim 6 wherein said protection means clamps the voltage on said timing control means to a predetermined voltage less than said first predetermined voltage.

Claim 9

The combination according to claim 1 further including a static latching switch coupled in series circuit between said timing capacitor and a point of reference potential, said static latching switch having a gate; and sensing circuit means comprising a transistor having at least an output electrode and a control electrode coupled with said output terminal and being normally nonconductive but rendered conductive in response to voltages on said output terminal exceeding a second predetermined voltage to apply a pulse on the output electrode thereof to the gate of said static latching switch to render said static latching switch conductive.

Claim 10

The combination according to claim 8 wherein said static latching switch is a silicon controlled rectifier.

Claim 11

The combination according to claim 1 wherein said gated unidirectional conductive means comprises a full wave rectifier circuit including at least first and second gated static latching switches coupled in common with said output terminal and each having a gate and each rendered conductive on opposite half-cycles of the alternating current input signal in response to gating signals applied to the gates thereof.

Claim 12

The combination according to claim 10 wherein said voltage responsive switch means comprises an avalanche breakdown device coupled in circuit between said output terminal and the gates of said static latching switches for supplying gating pulses to the gates of static latching switches upon avalanche breakdown thereof in response to said first predetermined voltage; and said timing control means comprises a capacitor coupled in a charging circuit with said output terminal.

Claim 13

The combination according to claim 11 wherein said static latching switches comprise silicon-controlled rectifiers coupled in a bridge rectifier circuit and said avalanche breakdown device comprises a diac.

Claim 14

A regulated power supply circuit for producing a direct current voltage in response to an alternating current input signal including in combination: a full-wave bridge rectifier having first and second input terminals, to which said alternating current input signal is applied, and having first and second output terminals, said first output terminal comprising the output terminal of said regulated power supply circuit and the second output terminal being coupled with a point of reference potential, said bridge rectifier circuit including at least first and second silicon-controlled rectifiers each having control gates and each coupled between a different one of first and second input terminals and one of said output terminals; shunt regulator circuit means coupled between said first output terminal and said point of reference potential and having a shunt regulator output terminal; a timing capacitor coupled in a charging circuit between said shunt regulator output terminal and said point of reference potential; a diac and a first resistor connected together at a first junction and coupled in series across said timing capacitor with said first junction coupled with the gates of said first and second silicon-controlled rectifiers; second and third resistors coupled together at a second junction; an auxiliary rectifier circuit having an output terminal coupled through said second and third resistors to said junction, said auxiliary rectifier circuit coUpled to receive said alternating current input signal, voltage responsive shunt means having a control input terminal coupled with said first output terminal of said full-wave bridge rectifier and coupled between said second junction and said point of reference potential, said shunt means rendered conductive to reduce the current supplied to said timing capacitor by said auxiliary rectifier circuit in response to a predetermined voltage level attained on the first output terminal of said bridge rectifier.

Claim 15

A regulated power supply circuit for producing a direct current voltage in response to an alternating current input signal including in combination: a full-wave bridge rectifier having first and second input terminals, to which said alternating current input signal is applied, and having first and second output terminals, said first output terminal comprising the output terminal of said regulated power supply circuit and the second output terminal being coupled with a point of reference potential, said bridge rectifier circuit including at least first and second silicon-controlled rectifiers each having control gates and each coupled between a different one of first and second input terminals and one of said output terminals; shunt regulator circuit means coupled between said first output terminal and said point of reference potential and having a shunt regulator output terminal; a timing capacitor coupled in a charging circuit between said shunt regulator output terminal and said point of reference potential; a diac and a first resistor connected together at a first junction and coupled in series across said timing capacitor with said first junction coupled with the gates of said first and second silicon-controlled rectifiers; second and third resistors coupled together at a second junction; an auxiliary rectifier circuit having an output terminal coupled through said second and third resistors to said junction, said auxiliary rectifier circuit coUpled to receive said alternating current input signal, voltage responsive shunt means having a control input terminal coupled with said first output terminal of said full-wave bridge rectifier and coupled between said second junction and said point of reference potential, said shunt means rendered conductive to reduce the current supplied to said timing capacitor by said auxiliary rectifier circuit in response to a predetermined voltage level attained on the first output terminal of said bridge rectifier.

Claim 16

The combination according to claim 13 further including overvoltage sensing means coupled to sense the voltage appearing between said first output terminal and the point of reference potential and operative to clamp the voltage on said timing capacitor to a level less than that necessary to effect avalanche breakdown of said diac, thereby terminating the application of gating pulses to the gates of said silicon-controlled rectifiers and thereby preventing the application of rectified direct current potential from said bridge rectifier to said first output terminal thereof.

Claim 17

The combination according to claim 13 wherein said bridge rectifier comprises first and second diodes and first and second silicon-controlled rectifiers, with said first and second diodes having the anodes thereof coupled in common with said second output terminal and the cathodes thereof coupled respectively with said first and second input terminals, said first and second silicon-controlled rectifiers having the cathodes thereof coupled in common with said first output terminal and the anodes thereof coupled respectively to said first and second input terminals; and said auxiliary rectifier comprises first and second diodes, the cathodes of which are coupled in common to form the output terminal thereof and the anodes of which are coupled respectively to said first and second input terminals of said bridge rectifier, whereby the first and second diodes of said auxiliary rectifier comprise a full wave rectifier circuit with the first and second diodes of said bridge rectifier such that the first and second diodes of said bridge rectifier perform a dual function in both said bridge rectifier and said auxiliary rectifier circuits.

Claim 18

The combination according to claim 13 further including means coupled to sense the current flow through said silicon controlled bridge rectifier for clamping the potential on said timing capacitor to a voltage less than the voltage required to cause breakdown of said diac, said sensing means being disabled in response to cessation of current flow through a conductive silicon-controlled rectifier in response to phase reversal of said alternating current input signal.

Claim 19

The combination according to claim 16 wherein said sensing means comprises a transistor, the collector of which is coupled with said first junction, the emitter of which is coupled with said second output terminal of said rectifier bridge, and the base thereof is coupled in circuit with said point of reference potential.

Claim 20

The combination according to claim 17 wherein said transistor is an NPN transistor and the first output terminal of said bridge rectifier comprises the positive output terminal thereof and the second output terminal of said bridge rectifier comprises the negative output terminal thereof.

Claim 21

A power supply circuit for producing a direct current voltage in response to an alternating current input signal including in combination: a first rectifier circuit having at least one input terminal to which said alternating current input signal is applied and having at least one output terminal comprising the output terminal of said power supply circuit, said first rectifier circuit including at least one silicon controlled rectifier having a control gate and coupled between said input terminal and said output terminal; control circuit means coupled with said output terminal and with the gate of said silicon controlled rectifier for controlling the cOnductivity of such rectifier in response to the direct current voltage appearing on said output terminal; an auxiliary rectifier circuit having an output terminal coupled in circuit with the output terminal of said first rectifier circuit and having at least one input terminal coupled to receive said alternating current input signal; and voltage responsive shunt means having a control terminal coupled with said output terminal of said first rectifier circuit and coupled between the output terminal of said auxiliary rectifier and a point of reference potential, said shunt means rendered conductive to reduce the effect on said control circuit means by said auxiliary rectifier circuit in response to a predetermined voltage level attained on the output terminal of said first rectifier.

Claim 22

A power supply circuit for producing a direct current voltage in response to an alternating current input signal including in combination: a first rectifier circuit having at least one input terminal to which said alternating current input signal is applied and having at least one output terminal comprising the output terminal of said power supply circuit, said first rectifier circuit including at least one silicon controlled rectifier having a control gate and coupled between said input terminal and said output terminal; control circuit means coupled with said output terminal and with the gate of said silicon controlled rectifier for controlling the cOnductivity of such rectifier in response to the direct current voltage appearing on said output terminal; an auxiliary rectifier circuit having an output terminal coupled in circuit with the output terminal of said first rectifier circuit and having at least one input terminal coupled to receive said alternating current input signal; and voltage responsive shunt means having a control terminal coupled with said output terminal of said first rectifier circuit and coupled between the output terminal of said auxiliary rectifier and a point of reference potential, said shunt means rendered conductive to reduce the effect on said control circuit means by said auxiliary rectifier circuit in response to a predetermined voltage level attained on the output terminal of said first rectifier.

Claim 23

The combination according to claim 19 further including first and second resistors coupled together at a junction and coupled in series between the output terminal of said auxiliary rectifier circuit and the output terminal of said first rectifier circuit, and wherein said voltage responsive shunt means is coupled between said junction and said point of reference potential.

Claim 24

The combination according to claim 20 wherein said voltage responsive shunt means includes a third resistor and a transistor switch means connected in series between said junction and said point of reference potential, said transistor switch being nonconductive when alternating current power is first applied to said first rectifier circuit and said auxiliary rectifier circuit and being rendered conductive in response to a predetermined voltage level attained on the output terminal of said first rectifier circuit to reduce the current supplied by said auxiliary rectifier circuit to said control circuit means.