Solid state relay

Claim 2

A solid state relay for switching a source of electrical energy between first and second load circuits in response to actuation signals applied thereto, said solid state relay comprising: a first semiconductor device having an input terminal coupled to said energy source and an output terminal coupled to the first load circuit, and having a control terminal; a second semiconductor device having an input terminal coupled to said energy source and an output terminal coupled to the second load circuit, and having a control terminal; a first isolating diode; first actuator means coupled through said first isolating diode to the control terminal of said first semiconductor device and controlled by said energy from said source of electrical energy in the absence of an actuation signal for permitting said first isolating diode to conduct and causing the impedance between said input and output terminals of said first semiconductor device to be at a low impedance level during periods of absence of said actuation signal, and controlled in response to the actuation signal for preventing said first isolating diode from conducting and causing said first semiconductor device to be at a high impedance level during periods of application of the actuation signal; a second isolating diode; and second actuator means coupled through said second isolating diode to the control terminal of said second semiconductor device and coupled to the reference potential plane of the energy source for preventing said second isolating diode from conducting and causing the impedance between said input and output terminals of said second semiconductor device to be at the high impedance level during periods of absence of said actuation signal, and controlled in response to the actuation signal for permitting said second isolating diode to conduct and for causing the impedance between said input and output terminals of said second semiconductor device to be at a low level during periods the actuation signal is applied; whereby said energy source is coupled to conduct through said first semiconductor device to said first load circuit in the absence of said actuation signals, and said energy source is coupled to conduct through said second semiconductor device to said second load circuit during the periods of application of said actuation signals.

Claim 3

The device of claim 1 wherein said first and second semiconductor devices are transistors and said input, output and control terminals are emitter, collector and base terminals respectively.

Claim 4

The device of claim 1 wherein said first and second semiconductor devices are each Darlington pair transistor circuits.

Claim 5

The invention in accordance with claim 1 including a resistor coupled between the input terminal and the control terMinal of each of said first and second semiconductor devices.

Claim 6

The device of claim 1 wherein said first actuator means comprises: a driver circuit including a transistor having emitter, collector, and base terminals, with said collector terminal coupled through said first isolating diode to the control terminal of said first semiconductor device, and the emitter terminal coupled to the reference potential plane of the energy source; first bias means coupled to said base terminal for electrically coupling said base terminal to the reference potential plane in response to the actuation signals; and second bias means coupled to said base terminal for electrically coupling said base terminal to said energy source in the absence of the actuation signal.

Claim 7

The invention in accordance with claim 5 wherein said second bias means includes said second isolating diode.

Claim 8

The device of claim 5 wherein said second actuator means comprises a transistor having emitter, collector and base terminals, with the last mentioned collector terminal coupled through said second isolating diode to the control terminal of said second semiconductor device, the last mentioned emitter terminal coupled to the reference potential plane of the energy source; and further includes means for applying the actuation signals to the last mentioned base terminal.

Claim 9

A solid state switching device for switching a source of electrical energy between first and second load circuits in response to actuation signals applied thereto, said switching device comprising: a first semiconductor device having an input terminal and an output terminal series coupled between the energy source and the first load circuit, and having a control terminal; a second semiconductor device having an input terminal and an output terminal series coupled between the energy source and the second load circuit, and having a control terminal; a first isolating diode; first actuator means coupled through said first isolating diode to the control terminal of said first semiconductor device and controlled by said energy from said source of electrical energy in the absence of an actuation signal for causing the impedance between said input and output terminals of said first semiconductor device to be a first level during periods of absence of said actuation signal, and controlled in response to the actuation signal for causing said first semiconductor device to be at a second impedance level during periods of application of the actuation signal; a second isolating diode; and second actuator means coupled through said second isolating diode to the control terminal of said second semiconductor device and responding to the actuation signals for causing the impedance between said input and output terminals of said second semiconductor device to be at a first level during periods the actuation signal is applied and at the second level during periods of absence of said actuation signal; whereby said energy source is coupled through said first semiconductor device to said first load circuit in the absence of said actuation signals, and said energy source is coupled through said second semiconductor device to said second load circuit during the periods of application of said actuation signals; and wherein said first and second actuator means include means for switching the impedance level of the semiconductor device which is at the second impedance level to the first impedance level before switching the other of said semiconductor device to the second impedance level from the first impedance level during the transition periods upon application or removal of the actuation signals.

Claim 10

A solid state switching device for switching a source of electrical energy between first and second load circuits in response to actuation signals applied thereto, said switching device comprising: a first semiconductor device having an input terminal and an output terminal series coupled between the energy source and the first load circuit, and having a control terminal; a second semiconductor device having an input terminal and an output terminal series coupled between the energy source and the second load circuit, and having a control terminal; a first isolating diode; first actuator means coupled through said first isolating diode to the control terminal of said first semiconductor device and controlled by said energy from said source of electrical energy in the absence of an actuation signal for causing the impedance between said input and output terminals of said first semiconductor device to be a first level during periods of absence of said actuation signal, and controlled in response to the actuation signal for causing said first semiconductor device to be at a second impedance level during periods of application of the actuation signal; a second isolating diode; and second actuator means coupled through said second isolating diode to the control terminal of said second semiconductor device and responding to the actuation signals for causing the impedance between said input and output terminals of said second semiconductor device to be at a first level during periods the actuation signal is applied and at the second level during periods of absence of said actuation signal; whereby said energy source is coupled through said first semiconductor device to said first load circuit in the absence of said actuation signals, and said energy source is coupled through said second semiconductor device to said second load circuit during the periods of application of said actuation signals; and wherein said first and second actuator means include means for switching the impedance level of the semiconductor device which is at the second impedance level to the first impedance level before switching the other of said semiconductor device to the second impedance level from the first impedance level during the transition periods upon application or removal of the actuation signals.

Claim 11

A solid state switching device for switching a source of electrical energy between first and second load circuits in response to actuation signals applied thereto, said switching device comprising: a first semiconductor device having an input terminal and an output terminal series coupled between the eneRgy source and the first load circuit, and having a control terminal; a second semiconductor device having an input terminal and an output terminal series coupled between the energy source and the second load circuit, and having a control terminal; a first isolating diode; first actuator means coupled through said first isolating diode to the control terminal of said first semiconductor device and controlled by said energy from said source of electrical energy in the absence of an actuation signal for causing the impedance between said input and output terminals of said first semiconductor device to be a first level during periods of absence of said actuation signal, and controlled in response to the actuation signal for causing said first semiconductor device to be at a second impedance level during periods of application of the actuation signal; a second isolating diode; and second actuator means coupled through said second isolating diode to the control terminal of said second semiconductor device and responding to the actuation signals for causing the impedance between said input and output terminals of said second semiconductor device to be at a first level during periods the actuation signal is applied and at the second level during periods of absence of said actuation signal; whereby said energy source is coupled through said first semiconductor device to said first load circuit in the absence of said actuation signals, and said energy source is coupled through said second semiconductor device to said second load circuit during the periods of application of said actuation signals; and wherein said first and second actuator means include means for switching the impedance level of the semiconductor device which is at the first impedance level to the second impedance level before switching the other of said semiconductor device to the first impedance level from the second impedance level during the transition periods upon application or removal of the actuation signals.

Claim 12

A solid state switching device for switching a source of electrical energy between first and second load circuits in response to actuation signals applied thereto, said switching device comprising: a first semiconductor device having an input terminal and an output terminal series coupled between the eneRgy source and the first load circuit, and having a control terminal; a second semiconductor device having an input terminal and an output terminal series coupled between the energy source and the second load circuit, and having a control terminal; a first isolating diode; first actuator means coupled through said first isolating diode to the control terminal of said first semiconductor device and controlled by said energy from said source of electrical energy in the absence of an actuation signal for causing the impedance between said input and output terminals of said first semiconductor device to be a first level during periods of absence of said actuation signal, and controlled in response to the actuation signal for causing said first semiconductor device to be at a second impedance level during periods of application of the actuation signal; a second isolating diode; and second actuator means coupled through said second isolating diode to the control terminal of said second semiconductor device and responding to the actuation signals for causing the impedance between said input and output terminals of said second semiconductor device to be at a first level during periods the actuation signal is applied and at the second level during periods of absence of said actuation signal; whereby said energy source is coupled through said first semiconductor device to said first load circuit in the absence of said actuation signals, and said energy source is coupled through said second semiconductor device to said second load circuit during the periods of application of said actuation signals; and wherein said first and second actuator means include means for switching the impedance level of the semiconductor device which is at the first impedance level to the second impedance level before switching the other of said semiconductor device to the first impedance level from the second impedance level during the transition periods upon application or removal of the actuation signals.

Claim 13

A solid state switching device for switching a source of electrical energy between first and second load circuits in response to actuation signals applied thereto, said switching device comprising: a first semiconductor device having an input terminal and an output terminal series coupled between the energy source and the first load circuit, and having a control terminal; a second semiconductor device having an input terminal and an output terminal series coupled between the energy source and the second load circuit, and having a control terminal; a first isolating diode; first actuator means coupled through said first isolating diode to the control terminal of said first semiconductor device and controlled by said energy from said source of electrical energy in the absence of an actuation signal for causing the impedance between said input and output terminals of said first semiconductor device to be a first level during periods of absence of said actuation signal, and controlled in response to the actuation signal for causing said first semiconductor device to be at a second impedance level during periods of application of the actuation signal; a second isolating diode; and second actuator means coupled through said second isolating diode to the control terminal of said second semiconductor device and responding to the actuation signals for causing the impedance between said input and output terminals of said second semiconductor device to be at a first level during periods the actuation signal is applied and at the second level during periods of absence of said actuation signal; whereby said energy source is coupled through said first semiconductor device to said first load circuit in the absence of said actuation signals, and said energy source is coupled through said second semiconductor device to said second load circuit during the periods of application of said actuation signals; wherein said first actuator means comprises: a driver circuit including a transistor having emitter, collector, and base terminals, with said collector terminal coupled through said first isolating diode to the control terminal of said first semiconductor device, and the emitter terminal coupled to the reference potential plane of the energy source; first bias means coupled to said base terminal for electrically coupling said base terminal to the reference potential plane in response to the actuation signals; and second bias means coupled to said base terminal for electrically coupling said base terminal to said energy source in the absence of the actuation signal, said second bias means comprising a series diode-resistor combination.

Claim 14

A solid state switching device for switching a source of electrical energy between first and second load circuits in response to actuation signals applied thereto, said switching device comprising: a first semiconductor device having an input terminal and an output terminal series coupled between the energy source and the first load circuit, and having a control terminal; a second semiconductor device having an input terminal and an output terminal series coupled between the energy source and the second load circuit, and having a control terminal; a first isolating diode; first actuator means coupled through said first isolating diode to the control terminal of said first semiconductor device and controlled by said energy from said source of electrical energy in the absence of an actuation signal for causing the impedance between said input and output terminals of said first semiconductor device to be a first level during periods of absence of said actuation signal, and controlled in response to the actuation signal for causing said first semiconductor device to be at a second impedance level during periods of application of the actuation signal; a second isolating diode; and second actuator means coupled through said second isolating diode to the control terminal of said second semiconductor device and responding to the actuation signals for causing the impedance between said input and output terminals of said second semiconductor device to be at a first level during periods the actuation signal is applied and at the second level during periods of absence of said actuation signal; whereby said energy source is coupled through said first semiconductor device to said first load circuit in the absence of said actuation signals, and said energy source is coupled through said second semiconductor device to said second load circuit during the periods of application of said actuation signals; wherein said first actuator means comprises: a driver circuit including a transistor having emitter, collector, and base terminals, with said collector terminal coupled through said first isolating diode to the control terminal of said first semiconductor device, and the emitter terminal coupled to the reference potential plane of the energy source; first bias means coupled to said base terminal for electrically coupling said base terminal to the reference potential plane in response to the actuation signals; and second bias means coupled to said base terminal for electrically coupling said base terminal to said energy source in the absence of the actuation signal, said second bias means comprising a series diode-resistor combination.

Claim 15

A solid state relay circuit for switching a first and second voltage source between a first pair and a second pair of load circuits, said first and second voltage sources having different potential levels, said relay circuit comprising: a pair of first switching transistors, each said first switching transistor having a control terminal, and having an input and an output terminal series coupled between one of said voltage sources and its associated first load circuits, and having a resistor coupled between the input and control terminals; a pair of second switching transistors, each said second switching transistor having a control terminal, and having an input and an output terminal series coupled between one of said voltages sources and its associated second load circuits, and having a resistor coupled between the input and control terminals; a first and second driving transistor, each having an input terminal, an output terminal and a base terminal, with the output terminal coupled to the reference potential plane of the energy sources; a first coupling means including an isolating diode for coupling the control terminal of each said first switching transistor to the input terminal of the first driving transistor; a second coupling means including an isolating diode for coupling the control terminal of each said second switching transistor to the input terminal of the second driving transistor; bias means coupled to the base terminals of each of the first and second driving transistors such that the first driving transistor is normally conducting and the second driving transistor is normally non-conducting; whereby the pair of first switching transistors coupled to the first driving transistor are normally conducting from the respective first and second voltage sources to the associated first load circuits and the pair of second switching transistors coupled to the second driving transistor are normally not conducting from the respective first and second voltage sources to the associated second load circuits; and input means coupled to the base terminals of said first and second driving transistors capable of reversing the conduction of said first and second driving transistors, whereby the pair of second switching transistors are conducting from the respective first and second voltage sources to the associated second load circuits, and the pair of first switching transistors are not conducting from the respective first and second voltage sources to the associated first load circuits; and whereby said isolating diodes for coupling the pair of switching transistors to a non-conductive driving transistor are effective to prevent current flow in the control terminals of said switching transistors resulting from the different potential levels of said voltage sources and thus prevent said switching transistors from inadvertently conducting.

Claim 16

A solid state relay circuit for switching a first and second voltage source between a first pair and a second pair of load circuits, said first and second voltage sources having different potential levels, said relay circuit comprising: a pair of first switching transistors, each said first switching transistor having a control terminal, and having an input and an output terminal series coupled between one of said voltage sources and its associated first load circuits, and having a resistor coupled between the input and control terminals; a pair of second switching transistors, each said second switching transistor having a control terminal, and having an input and an output terminal series coupled between one of said voltages sources and its associated second load circuits, and having a resistor coupled between the input and control terminals; a first and second driving transistor, each having an input terminal, an output terminal and a base terminal, with the output terminal coupled to the reference potential plane of the energy sources; a first coupling means including an isolating diode for coupling the control terminal of each said first switching transistor to the input terminal of the first driving transistor; a second coupling means including an isolating diode for coupling the control terminal of each said second switching transistor to the input terminal of the second driving transistor; bias means coupled to the base terminals of each of the first and second driving transistors such that the first driving transistor is normally conducting and the second driving transistor is normally non-conducting; whereby the pair of first switching transistors coupled to the first driving transistor are normally conducting from the respective first and second voltage sources to the associated first load circuits and the pair of second switching transistors coupled to the second driving transistor are normally not conducting from the respective first and second voltage sources to the associated second load circuits; and input means coupled to the base terminals of said first and second driving transistors capable of reversing the conduction of said first and second driving transistors, whereby the pair of second switching transistors are conducting from the respective first and second voltage sources to the associated second load circuits, and the pair of first switching transistors are not conducting from the respective first and second voltage sources to the associated first load circuits; and whereby said isolating diodes for coupling the pair of switching transistors to a non-conductive driving transistor are effective to prevent current flow in the control terminals of said switching transistors resulting from the different potential levels of said voltage sources and thus prevent said switching transistors from inadvertently conducting.

Claim 17

A solid state relay circuit for switching a plurality of electrical energy sources between a plurality of first and a plurality of second load circuits wherein a different set of first and second load circuits is associated with each of the energy sources, said solid state relay circuit comprising: a plurality of first switching transistors, each said first switching transistoRs having an input and an output terminal series coupled between a different one of said energy sources and its associated first load circuit, and each of said first switching transistors having a control terminal; a plurality of second switching transistors, each said second switching transistors having an input and an output terminal series coupled between a different one of said energy sources and its associated second load circuit, and each of said second switching transistors having a control terminal; a first driving transistor having an input and output terminal, and a base terminal, with the output terminal coupled to the reference potential plane of the energy sources; coupling means including an isolating diode for coupling the control terminal of each of said first switching transistors to the input terminal of said first driving transistor; a second driving transistor having an input and output terminal, and a base terminal, with the output terminal coupled to the reference potential plane of the energy source; coupling means including an isolating diode for coupling the control terminal of each of said second switching transistors to the input terminal of said second driving transistor; bias means including circuit means coupling at least one of said energy sources to the base terminal of said first driving transistor for normally biasing said first driving transistor in a conductive state and said second driving transistor in a non-conductive state; and input means including circuit means coupled to the base terminals of said first and second driving transistors capable of reversing the state of conduction of said first and second driving transistors; whereby the isolating diodes coupled to the control terminals of said first switching transistors are effective to enable each of the energy sources coupled to its associated first load circuit through one of said first switching transistors to operate as a separate isolated circuit; and whereby the isolating diodes coupled to the control terminals of said second switching transistors are effective to enable each of the energy sources coupled to its associated second load circuit through one of said second switching transistors to operate as a separate isolated circuit.

Claim 18

A solid state relay circuit for switching a plurality of electrical energy sources between a plurality of first and a plurality of second load circuits wherein a different set of first and second load circuits is associated with each of the energy sources, said solid state relay circuit comprising: a plurality of first switching transistors, each said first switching transistoRs having an input and an output terminal series coupled between a different one of said energy sources and its associated first load circuit, and each of said first switching transistors having a control terminal; a plurality of second switching transistors, each said second switching transistors having an input and an output terminal series coupled between a different one of said energy sources and its associated second load circuit, and each of said second switching transistors having a control terminal; a first driving transistor having an input and output terminal, and a base terminal, with the output terminal coupled to the reference potential plane of the energy sources; coupling means including an isolating diode for coupling the control terminal of each of said first switching transistors to the input terminal of said first driving transistor; a second driving transistor having an input and output terminal, and a base terminal, with the output terminal coupled to the reference potential plane of the energy source; coupling means including an isolating diode for coupling the control terminal of each of said second switching transistors to the input terminal of said second driving transistor; bias means including circuit means coupling at least one of said energy sources to the base terminal of said first driving transistor for normally biasing said first driving transistor in a conductive state and said second driving transistor in a non-conductive state; and input means including circuit means coupled to the base terminals of said first and second driving transistors capable of reversing the state of conduction of said first and second driving transistors; whereby the isolating diodes coupled to the control terminals of said first switching transistors are effective to enable each of the energy sources coupled to its associated first load circuit through one of said first switching transistors to operate as a separate isolated circuit; and whereby the isolating diodes coupled to the control terminals of said second switching transistors are effective to enable each of the energy sources coupled to its associated second load circuit through one of said second switching transistors to operate as a separate isolated circuit.

Claim 19

The invention in accordance with claim 12 wherein said bias means for coupling at least one of the energy sources to the base terminal of said first driving circuit includes the coupling means for coupling the plurality of second switching transistors to the collector terminal of said second driving circuit.

Claim 20

A solid state switching device for switching a source of electrical energy between first and second load circuits in response to actuation signals applied thereto, said switching device comprising: a first semiconductor device having an input terminal and an output terminal series coupled between the energy source and the first load circuit, and having a control terminal; a second semiconductor device having an input terminal and an output terminal series coupled between the energy source and the second load circuit, and having a control terminal; a first isolating diode; first actuator means coupled through said first isolating diode to the control terminal of said first semiconductor device and controlled by said energy from said source of electrical energy in the absence of an actuation signal for causing the impedance between said input and output terminals of said first semiconductor device to be a first level during periods of absence of said actuation signal, and controlled in response to the actuation signal for causing said first semiconductor device to be at a second impedance level during periods of application of the actuation signal; a second isolating diode; and second actuator means coupled through said second isolating diode to the control terminal of said second semiconductor device and responding to the actuation signals for causing the impedance between said input and output terminals of said second semiconductor device to be at a first level during periods the actuation signal is applied and at the second level during periods of absence of said actuation signal; whereby said energy source is coupled through said first semiconductor device to said first load circuit in the absence of said actuation signals, and said energy source is coupled through said second semiconductor device to said second load circuit during the periods of application of said actuation signals; and wherein each said first and second semiconductor devices include an n-p-n-transistor, and a p-n-p transistor, each said transistor having collector, emitter and base terminals with the collector and emitter terminals of said n-p-n transistor corresponding to the input and output terminal of said semiconductor device, with the collector and emitter terminals of said p-n-p transistor respectively coupled between the base terminal of said n-p-n transistor and said energy source, and with the base terminal of said p-n-p transistor corresponding to the control terminal of said semiconductor device.

Claim 21

A solid state switching device for switching a source of electrical energy between first and second load circuits in response to actuation signals applied thereto, said switching device comprising: a first semiconductor device having an input terminal and an output terminal series coupled between the energy source and the first load circuit, and having a control terminal; a second semiconductor device having an input terminal and an output terminal series coupled between the energy source and the second load circuit, and having a control terminal; a first isolating diode; first actuator means coupled through said first isolating diode to the control terminal of said first semiconductor device and controlled by said energy from said source of electrical energy in the absence of an actuation signal for causing the impedance between said input and output terminals of said first semiconductor device to be a first level during periods of absence of said actuation signal, and controlled in response to the actuation signal for causing said first semiconductor device to be at a second impedance level during periods of application of the actuation signal; a second isolating diode; and second actuator means coupled through said second isolating diode to the control terminal of said second semiconductor device and responding to the actuation signals for causing the impedance between said input and output terminals of said second semiconductor device to be at a first level during periods the actuation signal is applied and at the second level during periods of absence of said actuation signal; whereby said energy source is coupled through said first semiconductor device to said first load circuit in the absence of said actuation signals, and said energy source is coupled through said second semiconductor device to said second load circuit during the periods of application of said actuation signals; and wherein each said first and second semiconductor devices include an n-p-n-transistor, and a p-n-p transistor, each said transistor having collector, emitter and base terminals with the collector and emitter terminals of said n-p-n transistor corresponding to the input and output terminal of said semiconductor device, with the collector and emitter terminals of said p-n-p transistor respectively coupled between the base terminal of said n-p-n transistor and said energy source, and with the base terminal of said p-n-p transistor corresponding to the control terminal of said semiconductor device.

Claim 22

A solid state switching device for switching a source of electrical energy between first and second load circuits in response to actuation signals applied thereto, said switching device comprising: a first semiconductor device having an input terminal and an output terminal series coupled between the energy source and the first load circuit, and having a control terminal; a second semiconductor device having an input terminal and an output terminal series coupled between the energy source and the second load circuit, and having a control terminal; a first isolating diode; first actuator means coupled through said first isolating diode to the control terminal of said first semiconductor device and controlled by said energy from said source of electrical energy in the absence of an actuation signal for causing the impedance between said input and output terminals of said first semiconductor device to be a first level during periods of absence to said actuation signal, and controlled in response to the actuation signal for causing said first semiconductor device to be at a second impedance level during periods of application of the actuation signal; a second isolating diode; and second actuator means coupled through said second isolating diode to the control terminal of said second semiconductor device and responding to the actuation signals for causing the impedance between said input and output terminals of said second semiconductor device to be at a first level during periods the actuation signal is applied and at the second level during periods of absence of said actuation signal; whereby said energy source is coupled through said first semiconductor device to said first load circuit in the absence of said actuation signals, and said energy source is coupled through said second semiconductor device to said second load circuit during the periods of application of said actuation signals; and wherein the coupling of each said first and second actuator means to the respective control terminals of said first and second semiconductor devices includes a constant current diode.

Claim 23

A solid state switching device for switching a source of electrical energy between first and second load circuits in response to actuation signals applied thereto, said switching device comprising: a first semiconductor device having an input terminal and an output terminal series coupled between the energy source and the first load circuit, and having a control terminal; a second semiconductor device having an input terminal and an output terminal series coupled between the energy source and the second load circuit, and having a control terminal; a first isolating diode; first actuator means coupled through said first isolating diode to the control terminal of said first semiconductor device and controlled by said energy from said source of electrical energy in the absence of an actuation signal for causing the impedance between said input and output terminals of said first semiconductor device to be a first level during periods of absence to said actuation signal, and controlled in response to the actuation signal for causing said first semiconductor device to be at a second impedance level during periods of application of the actuation signal; a second isolating diode; and second actuator means coupled through said second isolating diode to the control terminal of said second semiconductor device and responding to the actuation signals for causing the impedance between said input and output terminals of said second semiconductor device to be at a first level during periods the actuation signal is applied and at the second level during periods of absence of said actuation signal; whereby said energy source is coupled through said first semiconductor device to said first load circuit in the absence of said actuation signals, and said energy source is coupled through said second semiconductor device to said second load circuit during the periods of application of said actuation signals; and wherein the coupling of each said first and second actuator means to the respective control terminals of said first and second semiconductor devices includes a constant current diode.

Claim 24

A solid state switching device for switching a plurality of electrical energy sources between a plurality of first and second load circuits wherein a different set of first and second load circuits is exclusively associated with each one of the energy sources, said switching device comprising: a plurality of first semiconductor devices, each said first semiconductor device having an input and an output terminal series coupled between a different one of said energy sources and its associated first load circuit, and each of said first semiconductor devices having a control terminal; a plurality of second semiconductor devices, each of said second semiconductor devices having an input terminal and an output terminal serieS coupled between a different one of said energy sources and its associated second load circuit, and each of said second semiconductor devices having a control terminal; first actuator means coupled to the control terminal of each of said first semiconductor devices and controlled by the electrical energy from the source of electrical energy of the largest potential magnitude in the absence of an actuation signal for causing the impedance between the input and output terminals of each said first semiconductor device to be at a first impedance level during the absence of the actuation signal, and controlled in response to the actuation signal for causing the impedance level of each said first semiconductor device to be at a second level during the periods of application of the actuation signal; said coupling of the first actuator means to the control terminal of each of said first semiconductor devices including isolating means for isolating each of said first semiconductor devices such that the current path from each energy source through its associated first semiconductor device to its associated first load circuit operates as a separate, isolated circuit; second actuator means coupled to the control terminal of each said second semiconductor device and responding to said actuation signal for causing the impedance level between the input and output terminals of each said second semiconductor device to be at a first level during periods the actuation signal is applied and at a second level during periods of absence of said actuation signal; said coupling of the second actuator means to the control terminal of each of said second semiconductor devices including isolating means for isolating each of said second semiconductor devices such that the current path from each energy source through its associated second semiconductor device to its associated load circuit operates as a separate isolated circuit; whereby each of said plurality of energy sources is coupled through its associated first semiconductor device to its associated first load circuit in the absence of said actuation signal, and each of said plurality of said energy sources is coupled through its associated second semiconductor device to its associated second load circuit during the periods of application of said actuation signal.

Claim 25

A solid state switching device for switching a plurality of electrical energy sources between a plurality of first and second load circuits wherein a different set of first and second load circuits is exclusively associated with each one of the energy sources, said switching device comprising: a plurality of first semiconductor devices, each said first semiconductor device having an input and an output terminal series coupled between a different one of said energy sources and its associated first load circuit, and each of said first semiconductor devices having a control terminal; a plurality of second semiconductor devices, each of said second semiconductor devices having an input terminal and an output terminal serieS coupled between a different one of said energy sources and its associated second load circuit, and each of said second semiconductor devices having a control terminal; first actuator means coupled to the control terminal of each of said first semiconductor devices and controlled by the electrical energy from the source of electrical energy of the largest potential magnitude in the absence of an actuation signal for causing the impedance between the input and output terminals of each said first semiconductor device to be at a first impedance level during the absence of the actuation signal, and controlled in response to the actuation signal for causing the impedance level of each said first semiconductor device to be at a second level during the periods of application of the actuation signal; said coupling of the first actuator means to the control terminal of each of said first semiconductor devices including isolating means for isolating each of said first semiconductor devices such that the current path from each energy source through its associated first semiconductor device to its associated first load circuit operates as a separate, isolated circuit; second actuator means coupled to the control terminal of each said second semiconductor device and responding to said actuation signal for causing the impedance level between the input and output terminals of each said second semiconductor device to be at a first level during periods the actuation signal is applied and at a second level during periods of absence of said actuation signal; said coupling of the second actuator means to the control terminal of each of said second semiconductor devices including isolating means for isolating each of said second semiconductor devices such that the current path from each energy source through its associated second semiconductor device to its associated load circuit operates as a separate isolated circuit; whereby each of said plurality of energy sources is coupled through its associated first semiconductor device to its associated first load circuit in the absence of said actuation signal, and each of said plurality of said energy sources is coupled through its associated second semiconductor device to its associated second load circuit during the periods of application of said actuation signal.

Claim 26

The device of claim 16 wherein said first and second actuator means includes means for momentarily holding the impedance level between the input and output terminals of the semiconductor devices of each of said sets of first and second semiconductor devices which are at the first impedance level at that level until the impedance of the other semiconductor device of the set is switched to the first level during the transition periods upon application or removal of the actuation signal.

Claim 27

The device of claim 16 wherein said first and second actuation means includes means for switching the impedance level of one of the semiconductor devices of each set of semiconductor devices from the first to the second impedance level before switching the other semiconductor device of each set from the second to the first impedance level during the transition period upon application or removal of the actuation signal.

Claim 28

The device of claim 16 wherein said first and second actuation means includes means for switching the impedance level of one of the semiconductor devices of each set of semiconductor devices from the second to the first impedance level before switching the other semiconductor device of each set from the first to the second impedance level during the transition period upon application or removal of the actuation signal.

Claim 29

The invention in accordance with claim 16 including a resistor coupled between the input terminal and the control terminal of each of said first and second semiconductor devices.

Claim 30

The invention in accordance with claim 16 wherein said isolating means for isolating each of said first and second semiconductor devicEs comprises a diode connected into the control terminal of each of said first and second semiconductor devices for preventing current flow therein when said electrical energy sources are at different potential levels.

Claim 31

The invention in accordance with claim 21 wherein said switching transistors and said driving transistors are of complementary type.

Claim 32

The device of claim 16 wherein said first actuator means comprises: a driver circuit including a transistor having emitter, collector and base terminals, wherein said isolating means includes isolating diodes, and wherein said collector terminal is coupled to the control terminal of each of said first semiconductor devices through one of said isolating diodes, and said emitter terminal of said transistor is coupled to the reference potential plane of the energy sources; first bias means coupled to the base terminal for electrically coupling said base terminal to the reference potential plane in response to the actuation signals; and second bias means coupled to said base terminal for electrically coupling said base terminal to the energy source of the largest potential magnitude in the absence of said actuation signal.

Claim 33

The device of claim 23 wherein said second bias means comprises a diode-resistor network for connecting the energy source of the largest voltage magnitude to the base terminal of the driver circuit.

Claim 34

The device of claim 23 wherein said second actuator means comprises a transistor having emitter, collector, and base terminals with the collector terminal coupled to said control terminal of each of said second semiconductor devices through one of said isolating diodes, said emitter terminal coupled to the reference potential plane of said energy sources, and including means for applying the actuation signal to said last mentioned base terminal.