Solid state switching circuits

Claim 2

A switching circuit comprising: an input terminal; an output terminal; a first resistor connected between said input terminal and ground; a second resistor connected between said output terminal and ground; first and second pairs of unilaterally conducting devices, each of said devices having an anode and a cathode and displaying an impedance of low value when conducting and an impedance of high value when non conducting, the devices in one of said pairs being cOnnected in series with the cathodes thereof joined at a first common terminal between said input and said output terminals and the devices in the other of said pairs being connected in series with the anodes thereof joined at a second common terminal between said input and said output terminals; a source of potential having a positive and a negative potential point, and an intermediate potential point connected to ground; a first circuit including a fixed impedance element and a first controllable impedance element connected in series across said positive and negative points with the junction thereof connected to the cathodes of said one pair of unilaterally conducting devices; a second circuit including a fixed impedance element and a second controllable impedance element connected in series across said positive and negative points with the junction thereof connected to the anodes of said other pair of unilaterally conducting devices; and means for conjointly increasing or decreasing the impedances of said first and second variable impedance elements to increase or decrease, respectively, the values of impedance of each of said unilaterally conducting devices.

Claim 3

The switching circuit of claim 1 including first capacitance means coupling said first common terminal to ground, and second capacitance means coupling said second common terminal to ground.

Claim 4

The switching circuit of claim 1 including means coupling a control potential to a control electrode of said first controllable impedance element, and means coupling the output of said first controllable impedance element to a control electrode of said second controllable impedance element.

Claim 5

The switching circuit of claim 3 including first capacitance means coupling said first common terminal to ground, and second capacitance means coupling said second common terminal to ground.

Claim 6

A switching circuit comprising: an input terminal; an output terminal; a first resistor connected between said input terminal and ground; a second resistor connected between said output terminal and ground; first and second pairs of diodes, each of said diodes having an anode and a cathode, the diodes in one of said pairs being connected in series with the cathodes thereof joined at a first common terminal between said input and said output terminals and the diodes in the other of said pairs being connected in series with the anodes thereof joined at a second common terminal between said input and said output terminals; a source of potential having a positive and a negative potential point, and an intermediate potential point connected to ground; a first circuit including a first transistor and a first resistor connected in series with the emitter and collector electrodes of said first transistor between said positive and negative potential points, the collector electrode of said first transistor being connected to the common cathodes of one of said pairs of diodes; a second circuit including a second transistor and a second resistor connected in series with the emitter and collector electrodes of said second transistor between said positive and negative potential points, the collector electrode of said second transistor being connected to the common anodes of the other of said pairs of diodes; means coupling the collector electrode of said first transistor to the base electrode of said second transistor; and means selectively coupling a control potential to the base electrode of said first transistor, said control potential at one amplitude level producing conduction in said first transistor so as to bias said diodes nonconductive and, at another amplitude level, rendering said first transistor nonconductive so as to bias said diodes conductive to establish a conductive path between said input terminal and said output terminal.

Claim 7

A switching circuit comprising: an input terminal; an output terminal; a first resistor connected between said input terminal and ground; a second resistor connected between said output terminal and ground; first and second pairs of diodes, each of said diodes having an anode and a cathode, the diodes in one of said pairs being connected in series with the cathodes thereof joined at a first common terminal between said input and said output terminals and the diodes in the other of said pairs being connected in series with the anodes thereof joined at a second common terminal between said input and said output terminals; a source of potential having a positive and a negative potential point, and an intermediate potential point connected to ground; a first circuit including a first transistor and a first resistor connected in series with the emitter and collector electrodes of said first transistor between said positive and negative potential points, the collector electrode of said first transistor being connected to the common cathodes of one of said pairs of diodes; a second circuit including a second transistor and a second resistor connected in series with the emitter and collector electrodes of said second transistor between said positive and negative potential points, the collector electrode of said second transistor being connected to the common anodes of the other of said pairs of diodes; means coupling the collector electrode of said first transistor to the base electrode of said second transistor; and means selectively coupling a control potential to the base electrode of said first transistor, said control potential at one amplitude level producing conduction in said first transistor so as to bias said diodes nonconductive and, at another amplitude level, rendering said first transistor nonconductive so as to bias said diodes conductive to establish a conductive path between said input terminal and said output terminal.

Claim 8

The switching circuit of claim 5 including first capacitance means coupling said first common terminal to grouNd, and second capacitance means coupling said second common terminal to ground.