A controller (3) includes an AC voltage generator (12) that generates first to Nth AC voltages, a DC voltage generator (13) that converts the first to Nth AC voltages into first to Nth DC voltages, respectively, and a driver (14) that turns on and off a switch (1) based on the first to Nth DC voltages. The AC voltage generator (12) includes first to Nth isolation transformers (T1 to TN). The primary windings of the nth and (n+1)th isolation transformers receive an AC source voltage. The nth to first isolation transformers are sequentially connected. The (n+1)th to Nth isolation transformers are sequentially connected. The first to Nth isolation transformers respectively output the first to Nth AC voltages from their respective secondary windings.

A switch driving circuit that drives a switch is provided. The switch driving circuit includes: a surge detecting unit that detects a surge voltage caused by switching of a state of the switch; a speed setting unit that sets, based on the surge voltage detected by the surge detecting unit, a switching speed of the switch when the state of the switch is switched; and a fault determination unit that determines whether a fault has occurred on the surge detecting unit. The speed setting unit is configured to change a setting of the switching speed to a fault setting when the fault determination unit determines that a fault has occurred on the surge detecting unit, from a normal setting in a state where the fault determination unit determines that no fault has occurred on the surge detecting unit, while maintaining driving of the switch.

an electronic circuit according to an embodiment includes: a generation circuit generating a first clocksignal and a second clocksignal delayed from the first clocksignal; a first coupler transmitting one of the first and the second clocksignals by electromagnetic coupling; a first converter driven by the transmitted clocksignal and converting a first input signal into a first signal of a frequency corresponding to the transmitted clocksignal; a second coupler transmitting the first signal by electromagnetic coupling; a second converter converting the first signal into a second signal of a frequency corresponding to the first input signal with the other of the first and the second clocksignals; an output device outputting the second signal; and a protection circuit connected to a line through which the one of the first and the second clocksignals is transmitted between the first coupler and the first converter.

An output circuit receives a data signal biased within a first voltage range associated with a first power supply voltage and generates an output signal on an output node biased within a second voltage range in response to the data signal, the second voltage range is associated with a second power supply voltage greater than the first power supply voltage. The output circuit generates pull-up and pull-down signals that are within the first voltage range in response to the data signal. The output circuit includes an output driver circuit including a pull-up circuit and a pull-down circuit. The pull-up circuit, when activated, generates the output signal indicative of the second power supply voltage in response to a modified pull-up signal being the pull-up signal level-shifted to a third voltage range. The pull-down circuit, when activated, generates the output signal being the ground potential in response to the pull-down signal.

Circuitry for ultrasound devices is described. A multilevel pulser is described, which can provide bipolar pulses of multiple levels. The multilevel pulser includes a pulsing circuit and pulser and feedback circuit. Symmetric switches are also described. The symmetric switches can be positioned as inputs to ultrasound receiving circuitry to block signals from the receiving circuitry.

A single live line switch circuit includes a single live line connecting end, a switch unit, two wire channels, an on-state power obtaining circuit, an off-state power obtaining circuit, and an energy storage element. The single live line connecting end is connected to an external single live line. The on-state power obtaining circuit is connected to the single live line connecting end. The switch unit includes a fixed connecting end and a movable connecting end, and the fixed connecting end is connected to the on-state power obtaining circuit. The two wire channels are provided with a first connecting end and a second connecting end, respectively, and the movable connecting end of the switch unit is in contact with the first connecting end or the second connecting end. A control method of the single live line switch circuit is provided.

A single live line switch circuit includes a single live line connecting end, a switch unit, two wire channels, an on-state power obtaining circuit, an off-state power obtaining circuit, and an energy storage element. The single live line connecting end is connected to an external single live line. The on-state power obtaining circuit is connected to the single live line connecting end. The switch unit includes a fixed connecting end and a movable connecting end, and the fixed connecting end is connected to the on-state power obtaining circuit. The two wire channels are provided with a first connecting end and a second connecting end, respectively, and the movable connecting end of the switch unit is in contact with the first connecting end or the second connecting end. A control method of the single live line switch circuit is provided.

A high reliability AC load switching circuit is disclosed. In some embodiments, the AC load switching circuit includes a high-speed switch connected between the load and the voltage source, a cutoff switch connected between the load and the voltage source in parallel with the high-speed switch, and a level detector connected to the voltage source and to a control input of the high-speed switch. The high-speed switch may be a solid-state switch, for example, a TRIAC or a bidirectional switch, and the cutoff switch may be an electromechanical switch, for example, a relay. In some embodiments a snubber is connected in parallel with a solid-state switch. In some embodiments a microcontroller is connected to an electromechanical switch and the level detector. In some embodiments, both a first cutoff switch and a second cutoff switch are used.

A high reliability AC load switching circuit is disclosed. In some embodiments, the AC load switching circuit includes a high-speed switch connected between the load and the voltage source, a cutoff switch connected between the load and the voltage source in parallel with the high-speed switch, and a level detector connected to the voltage source and to a control input of the high-speed switch. The high-speed switch may be a solid-state switch, for example, a TRIAC or a bidirectional switch, and the cutoff switch may be an electromechanical switch, for example, a relay. In some embodiments a snubber is connected in parallel with a solid-state switch. In some embodiments a microcontroller is connected to an electromechanical switch and the level detector. In some embodiments, both a first cutoff switch and a second cutoff switch are used.

The present disclosure concerns a device for supplying an adjustable current configured to supply discrete values of the current belonging to different current ranges, with a pitch between two successive discrete values determined by that of said ranges to which each of the two successive discrete values belongs.