초록 ▼

A solid state circuit breaker which provides high voltage isolation between a control circuit and a power source is described. The circuit breaker comprises a receiver for providing a control signal in response to a transmitter that is electrically isolated from the receiver, a solid state switch th

A solid state circuit breaker which provides high voltage isolation between a control circuit and a power source is described. The circuit breaker comprises a receiver for providing a control signal in response to a transmitter that is electrically isolated from the receiver, a solid state switch that closes in response to the control signal thereby allowing a load current to flow through the switch, a current sensor for measuring the load current, and an inhibit circuit responsive to the current sensor for inhibiting the control signal when the load current exceeds a predetermined magnitude thereby opening the switch without adjusting the transmitter. After opening the switch, the inhibit circuit is responsive to the transmitter for allowing the control signal thereby closing the switch.

대표청구항 ▼

An optically coupled solid state circuit breaker which provides high voltage isolation between a control circuit and a power source, comprising a light emitting diode having terminals connectable to a control circuit for generating light in response to a current; a photodiode array for converting li

An optically coupled solid state circuit breaker which provides high voltage isolation between a control circuit and a power source, comprising a light emitting diode having terminals connectable to a control circuit for generating light in response to a current; a photodiode array for converting light generated by the light emitting diode into a photocurrent across first and second nodes; a solid state switch comprising a first field effect transistor with a first gate, first source and first drain, and a second field effect transistor with a second gate, second source and second drain, the first and second gates connected together and coupled to the first node, the first and second drains having terminals connectable to a power source which generates a load current, wherein the photocurrent produces a first voltage across the nodes which turns on the first and second field effect transistors thereby allowing the load current to flow; a current sensor comprising a first resistor connected between the first source and the second node, a second resistor connected between the second source and the second node, a first bipolar transistor with a first base connected to the first source, with a first emitter connected to the second source, and with a first collector, a second bipolar transistor with a second base connected to the second source, with a second emitter connected to the first source, and with a second collector connected to the first collector, and a third resistor connected between the first node and the collectors, such that when the load current flowing from the first source to the second source exceeds the predetermined magnitude then the first bipolar transistor turns on thereby providing a low voltage at the collectors, and when the load current flowing from the second source to the first source exceeds the predetermined magnitude then the second bipolar transistor turns on thereby providing the low voltage at the collectors; an inhibit circuit comprising a third field effect transistor with a third gate, third source and third drain, the third gate connected to the collectors, and the third source connected to the first node, a fourth resistor connected between the second node and the third drain, and a thyristor with an anode connected to the first node, with a cathode connected to the second node, and with a trigger gate connected to the third drain, wherein the low voltage at the collectors turns on the third field effect transistor which signals the trigger gate to turn on the thyristor thereby reducing the first voltage to a second voltage across the nodes which causes the first and second field effect transistors to turn off thereby opening the switch and blocking the load current, the thyristor remaining on until the control circuit turns off the light emitting diode; and a discharge circuit comprising a second diode with a second anode connected to the first node and with a second cathode connected to the first and second gates, and a fourth field effect transistor with a fourth gate, fourth source and fourth drain, the fourth gate connected to the first node, the fourth source connected to the first and second gates, and the fourth drain connected to the second node, wherein the first voltage turns off the fourth field effect transistor whereas the second voltage turns on the fourth field effect transistor which then rapidly transfers charge stored in the first and second gates to the second node thereby accelerating turning off the switch when the thyristor turns on.