A zero-crossing detection circuit for a trailing edge phase control dimmer circuit for controlling alternating current (AC) power to a load, wherein the circuit includes: a switching circuit for controlling delivery of AC power to the load by conducting power to the load in an ON state and not conducting power to the load in an OFF state; a switching control circuit for controlling turn-OFF and turn-ON of the switching circuit at each cycle of the AC; and a rectifier for rectifying the AC power in the non-conduction period to generate rectified dimmer voltage to be provided to the dimmer circuit, wherein the zero-crossing detection circuit includes a current sink circuit; wherein the current sink circuit has a low impedance at low instantaneous AC voltages; a comparator circuit configured to detect zero crossings of a first threshold value of the rectified dimmer voltage.

An integrated circuit (IC) for controlling the discharge of a capacitor coupled across first and second input terminals of a power converter circuit, wherein the first and second terminals for receiving an ac line voltage. The IC includes a switching element coupled across the first and second input terminals and a detector circuit. The detector circuit including first and second comparators that produce first and second output signals responsive to a zero-crossing event of the ac line voltage. The first and second output signals being used to generate a reset signal coupled to a timer circuit responsive to the zero-crossing event. When the reset signal is not received within a delay time period, the timer circuit outputs a discharge signal that turns the switching element on, thereby discharging the capacitor.

An integrated circuit (IC) for controlling the discharge of a capacitor coupled across first and second input terminals of a power converter circuit, wherein the first and second terminals for receiving an ac line voltage. The IC includes a switching element coupled across the first and second input terminals and a detector circuit. The detector circuit including first and second comparators that produce first and second output signals responsive to a zero-crossing event of the ac line voltage. The first and second output signals being used to generate a reset signal coupled to a timer circuit responsive to the zero-crossing event. When the reset signal is not received within a delay time period, the timer circuit outputs a discharge signal that turns the switching element on, thereby discharging the capacitor.

The power supply apparatus includes a control unit configured to determine a stand-by time period from making a connection of a switch unit to subjecting a second voltage conversion unit to activation according to an input voltage of the alternating current power supply detected by a voltage detection unit.

The power supply apparatus includes a control unit configured to determine a stand-by time period from making a connection of a switch unit to subjecting a second voltage conversion unit to activation according to an input voltage of the alternating current power supply detected by a voltage detection unit.

A method and system for designing and implementing a finite impulse response (FIR) filter to create a plurality of output signals, each output signal having the same frequency but at a different phase shift from the other output(s), is described. Values are determined for the resistors, or other elements having impedance values, in a FIR filter having a plurality of outputs, such that each output has the same frequency response but a different phase than the other output(s). This is accomplished by the inclusion of a phase factor in the time domain calculation of the resistor values that does not change the response in the frequency domain. The phase shift is constant and independent of the frequency of the output signal.

A method and system for designing and implementing a finite impulse response (FIR) filter to create a plurality of output signals, each output signal having the same frequency but at a different phase shift from the other output(s), is described. Values are determined for the resistors, or other elements having impedance values, in a FIR filter having a plurality of outputs, such that each output has the same frequency response but a different phase than the other output(s). This is accomplished by the inclusion of a phase factor in the time domain calculation of the resistor values that does not change the response in the frequency domain. The phase shift is constant and independent of the frequency of the output signal.

A control device for a frequency generator of an ion thruster is described. The control device permits the detection of zero-crossings in a current and/or voltage characteristic during specific time intervals only, which detection is inhibited during other time intervals. Any incorrect switching performance of the control device associated with erroneously detected zero-crossings is prevented accordingly. A low-pass filter filters harmonics out of the detected current and/or voltage characteristics. A time-delay element offsets stray delays in the detection of zero-crossings. Additionally, plasma energy protective apparatuses are described, which attenuate the impact of any power flashover from a thruster unit to a power supply unit of an ion thruster.

A buck-boost power converter and a control circuit for the buck-boost converter. The buck-boost power converter includes a first power switch and a second power switch coupled in series between an input port and a reference ground, and a third power switch and a fourth power switch coupled in series between an output port and the reference ground. The control circuit receives a pulse skipping control signal and a zero-crossing indication signal, and controls the second power switch and/or the third power switch to turn on when the pulse skipping control signal controls the buck-boost power converter to enter into a pulse skipping mode and the zero-crossing indication signal indicates that an output inductor current of the buck-boost power converter crosses zero.

A buck-boost power converter and a control circuit for the buck-boost converter. The buck-boost power converter includes a first power switch and a second power switch coupled in series between an input port and a reference ground, and a third power switch and a fourth power switch coupled in series between an output port and the reference ground. The control circuit receives a pulse skipping control signal and a zero-crossing indication signal, and controls the second power switch and/or the third power switch to turn on when the pulse skipping control signal controls the buck-boost power converter to enter into a pulse skipping mode and the zero-crossing indication signal indicates that an output inductor current of the buck-boost power converter crosses zero.