A bidirectional switch for the control of power from an AC source to a load is described. The approach uses power MOSFETs in a bidirectional switch subcircuit configuration having an optically coupled, electrically floating control circuit that self-biases the switches into the on state and uses an optically coupled control element to force the switches into the off state. The time constant of the control circuit is fast enough to allow phase control as well as on-off control. A boost circuit is included to ensure that the control voltage exceeds a threshold voltage of the MOSFETs to force an off state. A plurality of subcircuits can be easily cascaded to provide improved performance

A drive circuit is connected to a gate terminal of an FET connected to a DC power supply to be transformed and controlled to be turned on or off, and applies a voltage to the gate terminal to turn on the FET, the FET including a drain terminal to which a current is input, a source terminal that outputs the current input from the drain terminal, and the gate terminal that controls the current flowing from the drain terminal to the source terminal. A reverse bias circuit includes a capacitor connected to the source terminal of the FET, and a coil having one end connected between the drive circuit and the gate terminal and the other end connected between the capacitor and the source terminal.

A gate drive circuit includes a signal generation unit configured to generate a first gate drive signal, a signal isolation unit configured to produce, at an output side thereof in response to the first gate drive signal, a second gate drive signal electrically isolated from the signal generation unit, an output stage device configured to receive the second gate drive signal at an input side thereof and to produce a third gate drive signal at an output side thereof in response to the second gate drive signal, a first path connecting the output side of the signal isolation unit and the input side of the output stage device; and a second path connecting the output side of the signal isolation unit and the output side of the output stage device.

In a semiconductor relay module, inside a package, one of a pair of input parts of a first semiconductor relay is connected to a first input terminal, the other of the pair of input parts of the first semiconductor relay is connected to a second input terminal, one of a pair of input parts of a second semiconductor relay is connected to the second input terminal, the other of the pair of input parts of the second semiconductor relay is connected to the first input terminal, one of a pair of input parts of a third semiconductor relay is connected to a third input terminal, and the other of the pair of input parts of the third semiconductor relay is connected to the first input terminal or the second input terminal.

A circuit comprises a primary transistor connecting a primary voltage source to a load connector. A translator and a secondary transistor cause opening of the primary transistor when receiving an off command and cause closing of the primary transistor when receiving an on command. The secondary transistor is powered by a secondary voltage source. A microcontroller receives measurements of a load voltage at the load connector. The microcontroller detects a drop of the load voltage to determine a moment when the load becomes connected to the circuit while the off command is being issued. The microcontroller issues the on command in response to the determination. Successive brief on commands may be issued to initially control current build-up in the load. A system includes the microcontroller and a plurality of such circuits for powering plural loads.

A circuit comprises a primary transistor connecting a primary voltage source to a load connector. A translator and a secondary transistor cause opening of the primary transistor when receiving an off command and cause closing of the primary transistor when receiving an on command. The secondary transistor is powered by a secondary voltage source. A microcontroller receives measurements of a load voltage at the load connector. The microcontroller detects a drop of the load voltage to determine a moment when the load becomes connected to the circuit while the off command is being issued. The microcontroller issues the on command in response to the determination. Successive brief on commands may be issued to initially control current build-up in the load. A system includes the microcontroller and a plurality of such circuits for powering plural loads.

A signal distribution apparatus for distributing a stress signal to a plurality of devices under test (DUTs) is disclosed. The distribution apparatus includes a single input that receives the stress voltage signal to be distributed, a plurality of outputs that distribute the stress voltage signal to the plurality of DUTs, and a plurality of integrated current limiter and switch circuits. Each integrated current limiter and switch circuit connects a DUT of the plurality of DUTs to the single input through one of the plurality of outputs, and includes at least one combined switching and current limiting element.

According to one embodiment, a solid state relay with ultra low emissions is disclosed. The solid state relay includes one or more inputs for receiving a control signal, an input circuit for processing the received control signal. An output circuit responsive to the control signal to close the solid state relay so that power may be delivered from a power source to an electrical load. The input circuit can include zero-crossing functionality configured such that the solid state relay does not turn on until an AC source signal crosses from a negative value to a positive value or from a positive value to a negative value. The zero crossing functionality may comprise opto-couplers with zero crossing functionality. The input circuit may further comprise a low emission driver portion that is to reduce emissions during the portion after the initial start up.

According to one embodiment, a solid state relay with ultra low emissions is disclosed. The solid state relay includes one or more inputs for receiving a control signal, an input circuit for processing the received control signal. An output circuit responsive to the control signal to close the solid state relay so that power may be delivered from a power source to an electrical load. The input circuit can include zero-crossing functionality configured such that the solid state relay does not turn on until an AC source signal crosses from a negative value to a positive value or from a positive value to a negative value. The zero crossing functionality may comprise opto-couplers with zero crossing functionality. The input circuit may further comprise a low emission driver portion that is to reduce emissions during the portion after the initial start up.

A photocoupler of an embodiment includes a packaging member, a first and a second MOSFET, a semiconductor light receiving element, a semiconductor light emitting element, a first wiring part, and a sealing resin layer. The input terminal includes a first and a second lead. The output terminal includes a third and a fourth lead. The first conductive region includes a signal input part and a bend part. The fourth conductive region includes a signal input part and a bend part. The semiconductor light receiving element is joined to the first and second MOSFETs astride a gap part. The semiconductor light emitting element is joined onto a light receiving region. The first wiring part connects the source electrode of the first MOSFET and the source electrode of the second MOSFET.