Thyristor circuits for applying a voltage to a load

Claim 2

A circuit for applying a voltage to a load, comprising a thyristor having a control terminal and a pair of load terminals, first circuit means for coupling a voltage source to a load through said pair of thyristor load terminals, and second circuit means for coupling said thyristor control terminal to one of said thyristor load terminals to provide a triggering signal for said thyristor derived from said voltage source, said second circuit means including contact switching means and an inductor connected in conductive series circuit relation between said control terminal and said one thyristor load terminal for preventing arc discharge in said contact switching means upon contact closure.

Claim 3

The circuit of claim 1 wherein said contact switching means comprises a pair of mechanical contacts normally having an arc or glow discharge occurrence therebetween upon closure, and said inductor being of sufficiently high Q to prevent the occurrence of said discharge.

Claim 4

The circuit of claim 2 wherein said contact switching means comprises a reed switch having said pair of mechanical contacts.

Claim 5

The circuit of claim 1 wherein said contact switching means comprises a pair of mechanical contacts and said second circuit means further comprises a series connected resistor and capacitor in parallel circuit relation to said contacts.

Claim 6

The circuit of claim 1 wherein a series connected capacitor and inductor combination is connected in parallel circuit relation to said thyristor load terminals.

Claim 7

The circuit of claim 4 wherein said contact switching means comprises a reed switch having said pair of mechanical contacts.

Claim 8

A circuit for applying a voltage to a load, comprising a thyristor having a control terminal and a pair of load terminals, means for applying the voltage source to the load through said pair of thyristor load terminals, a capacitor circuit coupled across said pair of thyristor load terminals, and means for coupling said thyristor control terminal to one of said thyristor load terminals through mechanical contact switching means conductively series connected to an inductor to provide a triggering signal for said thyristor derived from said voltage source, said inductor preventing high frequency are discharge in said contact switching means upon contact closure.

Claim 9

A circuit for applying a voltage to a load, comprising a thyristor having a control terminal and a pair of load terminals, means for applying the voltage source to the load through said pair of thyristor load terminals, a capacitor circuit coupled across said pair of thyristor load terminals, and means for coupling said thyristor control terminal to one of said thyristor load terminals through mechanical contact switching means conductively series connected to an inductor to provide a triggering signal for said thyristor derived from said voltage source, said inductor preventing high frequency are discharge in said contact switching means upon contact closure.

Claim 10

The circuit of claim 7 wherein said switching means comprises a hermetically sealed reed switch normally producing a glow discharge therein due to high frequency current components flowing therethrough, and said inductor being such as to inhibit said current components to prevent the occurrence of said glow discharge in said switch.

Claim 11

The circuit of claim 7 wherein said switching means comprises a hermetically sealed reed switch normally producing a glow discharge therein due to high frequency current comPonents flowing therethrough, and a further capacitor circuit coupled across said reed switch for causing said current components to by-bass said switch to prevent the occurrence of said glow discharge therein.

Claim 12

The circuit of claim 7 further comprising an additional inductor connected in series with a capacitor in said capacitor circuit, and the series combination being coupled across said pair of thyristor load terminals.

Claim 13

In a thyristor circuit for applying a voltage to a load, comprising a thyristor having a control terminal and a pair of load terminals, commutation circuit means including a capacitor connected across said thyristor load terminals, load circuit means coupled to said thyristor load terminals for responsively switching a voltage source to the load in accordance with the state of said thyristor, gate circuit means for selectively coupling said thyristor control terminal to one of said thyristor load terminals through switch contacts to provide a triggering signal derived from said voltage source to effect the state of said thyristor, the improvement wherein said gate circuit means comprises an inductor conductively connected in series circuit relation to said switch contacts between said control terminal and said one thyristor load terminal so that the signal derived from said voltage source is conducted to said control terminal through said inductor upon closure of said switch contacts, and said inductor prevents high frequency arc discharge between said contacts upon closure.

Claim 14

In a thyristor circuit for applying a voltage to a load, comprising a thyristor having a control terminal and a pair of load terminals, commutation circuit means including a capacitor connected across said thyristor load terminals, load circuit means coupled to said thyristor load terminals for responsively switching a voltage source to the load in accordance with the state of said thyristor, gate circuit means for selectively coupling said thyristor control terminal to one of said thyristor load terminals through switch contacts to provide a triggering signal derived from said voltage source to effect the state of said thyristor, the improvement wherein said gate circuit means comprises an inductor conductively connected in series circuit relation to said switch contacts between said control terminal and said one thyristor load terminal so that the signal derived from said voltage source is conducted to said control terminal through said inductor upon closure of said switch contacts, and said inductor prevents high frequency arc discharge between said contacts upon closure.

Claim 15

In the thyristor circuit of claim 11, said inductor having a sufficiently high Q to prevent glow discharge between said switch contacts upon closure.

Claim 16

In the thyristor circuit of claim 11, said gate circuit means further comprising a series connected resistor and capacitor combination connected in parallel circuit relation to said switch contacts to prevent glow discharge between said contacts upon closure.

Claim 17

In the thyristor circuit of claim 11, said commutation circuit means including an inductor connected in series with said capacitor.

Claim 18

A circuit for applying a voltage to a load, comprising a triac having a gate, an anode and a cathode, a commutation circuit including a capacitor connected across the anode and cathode of said triac, means for coupling the anode and cathode in circuit relation to the load to apply a voltage source thereto in accordance with the state of said triac, and a series circuit combination of an inductor and a reed switch conductively connected between the anode and the gate of said triac to provide a triggering signal thereto.

Claim 19

A circuit for applying a voltage to a load, comprising a triac having a gate, an anode and a cathode, a commutation circuit including a capacitor connected across the anode and cathode of said triac, means for coupling the anode and cathode in circuit relation to the load to apply a voltage source thereto in accordance with the state of said triac, and a series circuit combination of an inductor and a reed switch conductively connected between the anode and the gate of said triac to provide a triggering signal thereto.

Claim 20

The circuit of claim 15 wherein said inductor has a sufficiently high Q to prevent glow discharge between the switch contacts of said reed switch upon closure.

Claim 21

The circuit of claim 15 further comprising a series connected resistor and capacitor combination connected in parallel circuit relation to said reed switch to prevent glow discharge between the contacts thereof upon closure.

Claim 22

The circuit of claim 15 wherein said commutation circuit includes an inductor connected in series with said capacitor.

Claim 23

A circuit for applying line voltage to a load, comprising a thyristor having a pair of load circuit terminals and a gate terminal; a load circuit coupled to said load circuit terminals for applying the line voltage to the load in response to the thyristor being in a conductive state; and a gate circuit including switch contacts and an inductor connected in conductive series circuit relation between said gate and the line voltage for supplying, from the line, a gate driving current through said inductor to effect said conductive state of the thyristor, said inductor preventing high frequency arc discharge between said contacts upon closure.

Claim 24

A circuit for applying line voltage to a load, comprising a thyristor having a pair of load circuit terminals and a gate terminal; a load circuit coupled to said load circuit terminals for applying the line voltage to the load in response to the thyristor being in a conductive state; and a gate circuit including switch contacts and an inductor connected in conductive series circuit relation between said gate and the line voltage for supplying, from the line, a gate driving current through said inductor to effect said conductive state of the thyristor, said inductor preventing high frequency arc discharge between said contacts upon closure.

Claim 25

A circuit for applying a voltage source to a load, comprising a thyristor having an anode, a cathode, and gate terminal; first circuit means coupled to said anode and cathode for applying said source to the load in response to the thyrisTor being in a conductive state; and second circuit means including switch contacts and an inductor for selectively applying a gate drive signal derived from said source to said gate terminal through said inductor to effect said conductive state of the thyristor, said inductor having a sufficiently high Q to prevent glow discharge between said contacts upon actuation.

Claim 26

A circuit for applying a voltage source to a load, comprising a thyristor having an anode, a cathode, and gate terminal; first circuit means coupled to said anode and cathode for applying said source to the load in response to the thyrisTor being in a conductive state; and second circuit means including switch contacts and an inductor for selectively applying a gate drive signal derived from said source to said gate terminal through said inductor to effect said conductive state of the thyristor, said inductor having a sufficiently high Q to prevent glow discharge between said contacts upon actuation.

Claim 27

A circuit for applying a voltage to a load, comprising a thyristor having a control terminal and a pair of load terminals, first circuit means coupled to said load terminals for applying a voltage source to the load in response to the thyristor being in a conductive state; second circuit means including switch contacts and an inductor connected in conductive series circuit relation between said control terminal and one of said load terminals; and means storing a charge in response to said voltage source and discharging through said second circuit means upon closure of said switch contacts, said inductor preventing high frequency arc discharge between said contacts upon closure.

Claim 28

A circuit for applying a voltage to a load, comprising a thyristor having a control terminal and a pair of load terminals, first circuit means coupled to said load terminals for applying a voltage source to the load in response to the thyristor being in a conductive state; second circuit means including switch contacts and an inductor connected in conductive series circuit relation between said control terminal and one of said load terminals; and means storing a charge in response to said voltage source and discharging through said second circuit means upon closure of said switch contacts, said inductor preventing high frequency arc discharge between said contacts upon closure.