Comb drive circuit for thyristors

Claim 2

In a control circuit for providing firing pulses to each of a plurality of gate controlled-switching elements, in combination, a source of operative voltage, switching means having a plurality of outputs and including control pulse-generating means, means for connecting said switching means across said source of operative voltage, a plurality of firing pulse-generating means, each of said firing pulse-generating means having a control junction, the operative condition of said firing pulse-generating means being controlled in accordance with the voltage of said control junctions, means for connecting said firing pulsegenerating means across said source, means for connecting said firing pulse-generating means to the gates of respective gate controlled-switching elements, means for connecting the control junctions of said firing pulse-generating means to respective outputs of said switching means, pulse suppression means, means for connecting said pulse suppression means in control relationship to the control junctions of said firing pulsegenerating means, means for connecting said pulse suppression means in pulse responsive relationship severally to one of said pulse-generating means, means for connecting said pulse suppression means to said source, transient conducting means, means for connecting said transient conducting means across said source and in energizing relationship to said pulse suppression means, the energization of said pulse suppression means serving to control the generation of firing pulses in said firing pulsegenerating means under all operating conditions of said switching means.

Claim 3

In a control circuit for providing a firing signal to each of a plurality of gate controlled-switching elements, in combination, a source of operating voltage, control pulse-generating means, control pulse responsive switching means having a plurality of outputs, means for connecting said control pulse-generating means and said switching means across said source of operating voltage, means for connecting said control pulse-generating means to said control pulse responsive switching means, a plurality of firing signal-generating means, each of said firing signal-generating means including a control junction, the operative condition of each of said firing pulse-generating means being controlled in accordance with the voltage of the respective control junction, means for connecting said firing signal-generating means across said source, means for connecting said firing signal generating means to the gates of respective gate controlled-switching elements, means for connecting the control junctions of said firing signal-generating means to respective outputs of said switching means, pulse suppression means, means for connecting said pulse suppression means in control relationship to the control junctions of each of said firing signal-generating means, means for connecting said pulse suppression means in pulse responsive relationship to said control pulse-generating means, means for connecting said pulse suppression means to said source, transient conducting means, means for connecting said transient conducting means across said source and in energizing relationship to said pulse suppression means, the energization of said pulse suppression means serving to control the generation of the firing signal by said firing signal-generating means under all operating conditions of switching means.

Claim 4

In a control circuit for providing a firing signal to each of a plurality of gate controlled-switching elements, in combination, a source of operating voltage, control pulse-generating means, control pulse responsive switching means having a plurality of outputs, means for connecting said control pulse-generating means and said switching means across said source of operating voltage, means for connecting said control pulse-generating means to said control pulse responsive switching means, a plurality of firing signal-generating means, each of said firing signal-generating means including a control junction, the operative condition of each of said firing pulse-generating means being controlled in accordance with the voltage of the respective control junction, means for connecting said firing signal-generating means across said source, means for connecting said firing signal generating means to the gates of respective gate controlled-switching elements, means for connecting the control junctions of said firing signal-generating means to respective outputs of said switching means, pulse suppression means, means for connecting said pulse suppression means in control relationship to the control junctions of each of said firing signal-generating means, means for connecting said pulse suppression means in pulse responsive relationship to said control pulse-generating means, means for connecting said pulse suppression means to said source, transient conducting means, means for connecting said transient conducting means across said source and in energizing relationship to said pulse suppression means, the energization of said pulse suppression means serving to control the generation of the firing signal by said firing signal-generating means under all operating conditions of switching means.

Claim 5

In a control circuit for providing firing pulses to each of a plurality of gate controlled-switching elements, the combination of a source of operative voltage, a plurality of firing pulse-generating means each having an output winding and a control junction, means for connecting said firing pulse-generating means across said source, means for connecting the output windings of said firing pulse-generating means to predetermined gate controlled-switching elements, the generation of firing pulses in each firing pulse-generating means being controlled in accordance with the voltage appearing at the respective control junction, switching means having a plurality of outputs and including control pulse-generating means, said switching means being arranged to produce a sequence of output voltage pulses generated by said control pulse-generating means, means for connecting said switching means across said source, means for connecting respective outputs of said switching means across said source, means for connecting respective outputs of said switching means in control relationship to the control junction of respective firing pulse-generating means, pulse suppression means, means for connecting said pulse suppression means in control voltage establishing relationship to each of said control junctions, means for connecting said pulse suppression means in pulse responsive relationship to one of said pulse-generating means and means for connecting said pulse suppression means to said source of operative voltage.

Claim 6

In a control circuit for providing firing pulses to each of a plurality of gate controlled-switching elements, the combination of a source of operative voltage, a plurality of firing pulse-generating means each having an output winding and a control junction, means for connecting said firing pulse-generating means across said source, means for connecting the output windings of said firing pulse-generating means to predetermined gate controlled-switching elements, the generation of firing pulses in each firing pulse-generating means being controlled in accordance with the voltage appearing at the respective control junction, switching means having a plurality of outputs and including control pulse-generating means, said switching means being arranged to produce a sequence of output voltage pulses generated by said control pulse-generating means, means for connecting said switching means across said source, means for connecting respective outputs of said switching means across said source, means for connecting respective outputs of said switching means in control relationship to the control junction of respective firing pulse-generating means, pulse suppression means, means for connecting said pulse suppression means in control voltage establishing relationship to each of said control junctions, means for connecting said pulse suppression means in pulse responsive relationship to one of said pulse-generating means and means for connecting said pulse suppression means to said source of operative voltage.

Claim 7

In a control circuit for providing firing pulses to each of pulses to each of a plurality of gate controlled-switching elements, in combination, a DC source, control pulse-generating means having output means, means for connecting said control pulse-generating means for connecting said control pulse-generating means across said DC source, control pulse responsive switching means having input means and a plurality of outputs, means for connecting said control pulse responsive switching means across said DC source, means for connecting the output means of said control pulse-generating means in switching control relationship to the input means of said control pulse responsive switching means, a plurality of firing pulse-generating means, for connecting said firing pulse-generating means across said DC source, each of said firing pulse-generating means having a control junction, the generation of firing pulses by each firing pulse-generating means being controlled in accordance with the voltage between the respective control junction and one terminal of said DC source, means for connecting the outputs of said control pulse responsive switching means to the control junctions of said firing pulse-generating means, variable conducting means having power circuit means and control circuit means, means for connecting the control circuit means of said variable conducting means between the output means of said control pulse-generating means and one terminal of said DC source, means for connecting the power circuit means of said variable conducting means between said control junction means and one terminal of said DC source.

Claim 8

In a control circuit for providing firing pulses to each of pulses to each of a plurality of gate controlled-switching elements, in combination, a DC source, control pulse-generating means having output means, means for connecting said control pulse-generating means for connecting said control pulse-generating means across said DC source, control pulse responsive switching means having input means and a plurality of outputs, means for connecting said control pulse responsive switching means across said DC source, means for connecting the output means of said control pulse-generating means in switching control relationship to the input means of said control pulse responsive switching means, a plurality of firing pulse-generating means, for connecting said firing pulse-generating means across said DC source, each of said firing pulse-generating means having a control junction, the generation of firing pulses by each firing pulse-generating means being controlled in accordance with the voltage between the respective control junction and one terminal of said DC source, means for connecting the outputs of said control pulse responsive switching means to the control junctions of said firing pulse-generating means, variable conducting means having power circuit means and control circuit means, means for connecting the control circuit means of said variable conducting means between the output means of said control pulse-generating means and one terminal of said DC source, means for connecting the power circuit means of said variable conducting means between said control junction means and one terminal of said DC source.

Claim 9

In a control circuit for providing firing pulses to a plurality of gate controlled-switching elements, in combination, a DC source, control pulse-generating means having output means, means for connecting said control pulse-generating means across said DC source, control pulse responsive switching means having input means and a plurality of outputs, means for connecting said switching means across said DC source, means for connecting the output means of said control pulse-generating means to the input means of said control pulse responsive switching means, a plurality of firing pulse-generating means each having a control junction, means for connecting said firing pulse-generating means across said DC source, the generation of firing pulses by each firing pulse-generating means being controlled in accordance with the potential between the respective control junction and one terminal of said DC source, a plurality of variable conducting means each having a power circuit and a control circuit, means for connecting the control circuits of said variable conducting means between one terminal of said DC source and respective outputs of said control pulse responsive switching means, means for connecTing the power circuits of said variable conducting means for connecting the power circuits of said variable conducting means between said one terminal of said DC source and respective control junctions of said firing pulse-generating means, means for connecting the control circuits of said variable conducting means between said one terminal of said DC source and the output means of said control pulse-generating means.

Claim 10

In a control circuit for providing firing pulses to a plurality of gate controlled-switching elements, in combination, a DC source, control pulse-generating means having output means, means for connecting said control pulse-generating means across said DC source, control pulse responsive switching means having input means and a plurality of outputs, means for connecting said switching means across said DC source, means for connecting the output means of said control pulse-generating means to the input means of said control pulse responsive switching means, a plurality of firing pulse-generating means each having a control junction, means for connecting said firing pulse-generating means across said DC source, the generation of firing pulses by each firing pulse-generating means being controlled in accordance with the potential between the respective control junction and one terminal of said DC source, a plurality of variable conducting means each having a power circuit and a control circuit, means for connecting the control circuits of said variable conducting means between one terminal of said DC source and respective outputs of said control pulse responsive switching means, means for connecTing the power circuits of said variable conducting means for connecting the power circuits of said variable conducting means between said one terminal of said DC source and respective control junctions of said firing pulse-generating means, means for connecting the control circuits of said variable conducting means between said one terminal of said DC source and the output means of said control pulse-generating means.

Claim 11

In a control circuit for providing firing pulses to a plurality of gate controlled switching elements, in combination, a DC source, a plurality of firing pulse generating means for energizing the gates of respective gate controlled-switching elements, means for connecting said firing pulse generating means across said DC source, each of said firing pulse-generating means including controllable conducting means having two power electrodes and a control electrode, said firing pulse-generating means being adapted to produce firing pulses during those periods when the potential between respective control electrodes and one terminal of said DC source exceeds a predetermined value, control pulse-generating means across the DC source, control pulse responsive switching means having input means and a plurality of outputs, means for connecting said switching means across said DC source, means for connecting the output means of said control pulse-generating means to the input means of said control pulse responsive switching means, means for connecting the outputs of said switching means in potential controlling relationship to the control electrodes of respective controllable conducting means, variable conducting means having a power circuit and a control circuit, means for connecting the control circuit of said variable conducting means between the output means of said control pulse-generating means and one terminal of said DC source, means for connecting the power circuit of said variable conducting means between said one terminal of said DC source and the control electrodes of said controllable conducting means, whereby the conduction of said variable conducting means reduces the potential of the control electrodes of said controllable conducting means below the level of potential required to sustain firing pulse generating activity.

Claim 12

In a control circuit for providing firing pulses to a plurality of gate controlled switching elements, in combination, a DC source, a plurality of firing pulse generating means for energizing the gates of respective gate controlled-switching elements, means for connecting said firing pulse generating means across said DC source, each of said firing pulse-generating means including controllable conducting means having two power electrodes and a control electrode, said firing pulse-generating means being adapted to produce firing pulses during those periods when the potential between respective control electrodes and one terminal of said DC source exceeds a predetermined value, control pulse-generating means across the DC source, control pulse responsive switching means having input means and a plurality of outputs, means for connecting said switching means across said DC source, means for connecting the output means of said control pulse-generating means to the input means of said control pulse responsive switching means, means for connecting the outputs of said switching means in potential controlling relationship to the control electrodes of respective controllable conducting means, variable conducting means having a power circuit and a control circuit, means for connecting the control circuit of said variable conducting means between the output means of said control pulse-generating means and one terminal of said DC source, means for connecting the power circuit of said variable conducting means between said one terminal of said DC source and the control electrodes of said controllable conducting means, whereby the conduction of said variable conducting means reduces the potential of the control electrodes of said controllable conducting means below the level of potential required to sustain firing pulse generating activity.