Abstract: An integrated magnetic for a low harmonics three-phase bidirectional front-end and also for AC/DC and DC/AC power converters. Its use enables reduction of the harmonics of the currents absorbed or injected to three-phase power line by using only one device which integrates a splitter and an inductor function. Compared to known solutions, cost, material and dimensions of the integrated magnetic device are reduced thanks to the magnetic core comprising three closed sub-assemblies and one or more jokes, separated by air-gaps from the sub-assemblies.

Abstract: Disclosed herein is a torque control method for a high-speed Switched Reluctance Motor (SRM), which controls a torque in the high-speed operation of a 2-phase SRM. In the torque control method for a high-speed SRM, a positive torque (T*mA) of an active phase (A phase) of the two phases of the SRM is compensated for based on a negative torque attributable to an inactive phase (B phase) of two phases during a compensation control enable interval (ENA) ranging from a time point at which the active phase (A phase) is turned on to a time point at which tail current of the inactive phase (B phase) remains. Accordingly, the present invention can remarkably reduce a torque ripple occurring in high-speed operation mode in consideration of the influence of a negative torque attributable to tail current.

Abstract: A high-voltage power source includes a switching unit configured to be driven according to a frequency signal, a voltage resonance unit configured to generate a voltage according to driving of the switching unit, a rectification unit configured to rectify and amplify the voltage generated by the voltage resonance unit, a separation unit configured to separate an alternating current generated by the voltage resonance unit and a direct current generated by the rectification unit from each other, and a current detection unit configured to detect the current generated by the voltage resonance unit.

Abstract: A power supply system comprises: a switching power supply for generating a DC voltage by rectifying and smoothing an AC voltage of an AC power supply; a control device switching the switching power supply between the normal mode and a power saving mode; and a low-capacity power supply circuit supplying electric power to the control device in the power saving mode. The low-capacity power supply circuit includes: two capacitors, each including one end connected to the AC power supply; a rectifier circuit that is electrically connected between the other ends of the capacitors, and rectifies the AC voltage applied between the first and second capacitors; and a zero-crossing detecting circuit that is connected to a current path at the rear stage of the rectifier circuit, and detects zero-crossing points of the AC power supply.

Abstract: A Low Forward Voltage Rectifier (LFVR) includes a bipolar transistor, a parallel diode, and a base current injection circuit disposed in an easy-to-employ two-terminal package. In one example, the transistor is a Reverse Bipolar Junction Transistor (RBJT), the diode is a distributed diode, and the base current injection circuit is a current transformer. Under forward bias conditions (when the voltage from the first package terminal to the second package terminal is positive), the LFVR conducts current at a rated current level with a low forward voltage drop (for example, approximately 0.1 volts). In reverse bias conditions, the LFVR blocks current flow. Using the LFVR in place of a conventional silicon diode rectifier in the secondary of a flyback converter reduces average power dissipation and increases power supply efficiency.

Abstract: Apparatus related to power factor are provided. A power supply provides regulated power to a load or loads. The power supply is coupled to a source of alternating-current (AC) voltage. A controller monitors the AC input voltage and a current loading of the power supply. The controller determines an activation time according to the monitoring and asserts a signal prior to a next zero crossing of the input voltage. The signal causes impedance circuitry to be coupled between a pair of input nodes, resulting in a lagging power-factor. The impedance circuitry is de-coupled from at least one of the input nodes after the zero crossing.

Abstract: The temperature dependence of detection characteristics in a wave detector circuit is suppressed. A bias resistor and/or a load resistor are/is constituted by a resistive element having a high temperature coefficient, whereby a shift in detected output along with a change in temperature of a wave detector diode included in a diode detector circuit is canceled by a shift in detected output along with a change in temperature of the bias resistor and/or a shift in detected output along with a change in temperature of the load resistor.

Abstract: A method for fabricating an integrated AC LED module comprises steps: forming a junction layer on a substrate, and defining a first growth area and a second growth area on the junction layer; respectively growing a Schottky diode and a LED on the first growth area and the second growth area; forming a passivation layer and a metallic layer on the Schottky diode, the LED and the substrate. Thereby, the Schottky diode is electrically connected with the LED via the metallic layer. Thus is promoted the reliability of electric connection of diodes, reduced the layout area of the module, and decreased the fabrication cost.

Abstract: A buck/boost rectifier. The rectifier is connectable to an alternating current power source and includes an upper bus, a lower bus, an upper rectifier, a lower rectifier, a pulse-width-modulation (PWM) controller, a phase-angle (PA) controller, and a capacitor. The upper rectifier is coupled to the upper bus, and the lower rectifier is coupled in a series-type relationship with the upper rectifier and to the lower bus. The PWM controller is coupled to the lower rectifier and is configured to boost a direct current (DC) voltage output by the rectifier. The PA controller is coupled to the lower rectifier and is configured to buck the DC voltage output by the rectifier. The capacitor is coupled between the upper bus and the lower bus.

Abstract: A rectifier building block has four electrodes: source, drain, gate and probe. The main current flows between the source and drain electrodes. The gate voltage controls the conductivity of a narrow channel under a MOS gate and can switch the RBB between OFF and ON states. Used in pairs, the RBB can be configured as a three terminal half-bridge rectifier which exhibits better than ideal diode performance, similar to synchronous rectifiers but without the need for control circuits. N-type and P-type pairs can be configured as a full bridge rectifier. Other combinations are possible to create a variety of devices.

Abstract: An alternating-current/direct-current converter includes a rectifier, a reactor, a capacitor, and a switching rectifier. The rectifier is configured to rectify alternating-current voltage output from an alternating-current power source, thereby converting the alternating-current voltage into direct-current voltage, and to output the direct-current voltage. The capacitor includes terminals. The switching rectifier is coupled to the AC power source and switchable to output the direct-current voltage to the capacitor.

Abstract: A semiconductor apparatus includes: a first transistor; a second transistor having a higher withstand voltage than the first transistor, a source of the second transistor coupled to a drain of the first transistor, a gate of the second transistor coupled to a source of the first transistor; a third transistor having a higher withstand voltage than the first transistor and a drain of the third transistor coupled to a drain of the second transistor; and a comparator that compares a source voltage of the first transistor with a source voltage of the third transistor, and controls a gate voltage of the first transistor.

Abstract: A primary side PFC driver circuit is disclosed that includes a switch control circuit for commanding a switch to allow an inductor coupled to an output load (e.g., LEDs) to transfer energy provided by an input voltage source. The switch control circuit provides two signals for commanding the switch. A first signal having a first frequency, with a duty cycle in proportion to the input voltage amplitude, commands the switch to allow the average input current to be proportional to the input voltage amplitude. A second signal having a second frequency higher than the first frequency pulses the output load with substantially constant current pulses based on a value of the first signal (e.g., while the first signal is high). The current pulses produce a substantially constant current in the output load.

Abstract: The present disclosure discloses an offline low voltage DC output circuit with integrated full bridge rectifiers. The offline low voltage DC output circuit comprises two depletion high voltage pass transistors and a bridge rectifier, wherein most of the voltage is dropped across the pass transistor device. In one embodiment, the offline low voltage DC output circuit further comprises a ballast resistor to minimize substrate injection.

Abstract: A primary side PFC driver circuit is disclosed that includes a switch control circuit for commanding a switch to allow an inductor coupled to an output load (e.g., LEDs) to transfer energy provided by an input voltage source. The switch control circuit provides two signals for commanding the switch. A first signal having a first frequency, with a duty cycle in proportion to the input voltage amplitude, commands the switch to allow the average input current to be proportional to the input voltage amplitude. A second signal having a second frequency higher than the first frequency pulses the output load with substantially constant current pulses based on a value of the first signal (e.g., while the first signal is high). The current pulses produce a substantially constant current in the output load.

Abstract: The present invention includes: a plurality of switching elements connected in series and connected between two ends of a DC power supply; a first control circuit to alternately turn on and off the switching elements in response to a constant oscillation frequency signal; a series circuit including a primary winding of a transformer and a capacitor connected together in series, and being connected to a connecting point between the switching elements, and to an end of the DC power supply; a rectifying/smoothing circuit to rectify and smooth a voltage in a secondary winding of the transformer thereby to output a DC voltage; a control switching element connected to two ends of the primary or secondary winding of the transformer; and a second control circuit to control the DC voltage at a predetermined voltage by turning on and off the control switching element.

Abstract: The present disclosure discloses a power converter providing a low output voltage from an offline AC. The power converter defines a voltage window for the input AC signal. Inside the voltage window, the rectified DC waveform is passed through to the output and the storage capacitor; outside the voltage window, the power converter is idle (or the output is blocked from input) and let the output storage capacitor alone supply the load.

Abstract: An AC-to-DC power supply apparatus and a power control structure and method thereof are provided. The provided method includes: making an AC-to-DC converter in the AC-to-DC power supply apparatus convert an AC input voltage in response to a driving signal, so as to generate a DC output voltage; sampling a rectified voltage relating to the AC input voltage, so as to provide a sampling signal; providing an output feedback signal relating to an output of the AC-to-DC converter; multiplying the sampling signal by the output feedback signal, so as to provide a product signal; performing a signal modulation on the product signal, so as to generate the driving signal to control a switching of a main power switch in the AC-to-DC converter; and performing an amplitude-limiting process on the sampling signal or the product signal.

Abstract: A power system for an alternating current power bus includes an electret operatively associated with the alternating current power bus. The electret includes an output having an alternating current voltage when the alternating current power bus is energized. A rectifier includes an input electrically interconnected with the output of the electret and an output having a direct current voltage responsive to the alternating current voltage of the output of the electret. A powered device includes an input electrically interconnected with the output of the rectifier. The powered device is powered responsive to the direct current voltage of the output of the rectifier.

Abstract: The temperature dependence of detection characteristics in a wave detector circuit is suppressed. A bias resistor and/or a load resistor are/is constituted by a resistive element having a high temperature coefficient, whereby a shift in detected output along with a change in temperature of a wave detector diode included in a diode detector circuit is canceled by a shift in detected output along with a change in temperature of the bias resistor and/or a shift in detected output along with a change in temperature of the load resistor.

Abstract: Provided is a discharge loop for power supply and the active control circuit thereof for actively regulating the discharging operation of the discharge loop of the power supply. The inventive active control circuit is able to disallow the current to flow through the bleeder resistor of the discharge loop to cause power loss when the input power of the power supply is applying, and provide a fast discharge path for the bleeder resistor to expedite the discharging operation when the input power of the power supply is interrupted. Therefore, the inventive active control circuit is able to reduce the power loss of the power supply and enhance the power efficiency of the power supply.

Abstract: A power adjustable, isolated and tranformerless AC to DC power circuit is revealed. The AC to DC power circuit includes a first reactance component, a second reactance component, a third reactance component and an AC power connected to form a loop. The third reactance component is connected to an input end of a full bridge rectifier and a filter capacitor is connected across to an output end of the full bridge rectifier for output of a stable low voltage DC. Thereby AC power is isolated to avoid electric conductance or shock. Moreover, the manufacturing cost is dramatically reduced, the power is saved, and no heat is generated. Furthermore, the reactance of the whole circuit is reduced so as to get high power factor. The AC to DC power circuit has no high frequency radiation, no radiation damage and no interference to sensitive electronic equipment.

Abstract: A power converter includes a DC port and an AC port. A set of controllable “DC” switches couples the DC port to a central series-resonant circuit, and a set of “AC switches couples the central circuit through a filter to the AC port. A switch control circuit responds to secondary-to-tertiary and inversion time percentages, and a modulator is responsive to the AC filter voltage and to the current at the AC port, for generating the inversion (inv) and secondary-to-tertiary (s2t) time percentages.

Abstract: Method of reducing common mode current (i) flowing between the internal ground (13) of an electrical circuit (4) and the earth, said circuit (4) being supplied by an electrical network (2) delivering an alternating voltage, method in which: a voltage is applied by the electrical network (2) between the internal ground (13) of the circuit (4) and the earth, and an additional voltage is applied between the internal ground (13) of the circuit (4) and the earth using an electronic component (21) interposed between the internal ground (13) of the circuit (4) and the earth, this additional voltage opposing the voltage applied by the electrical network (2) between the internal ground (13) and the earth, so as to reduce the common mode current (i).

Abstract: According to one embodiment, a power conversion apparatus includes a first LC circuit, a first switch, a second switch, a smoothing capacitor, a second LC circuit and a controller. The first switch is connected to the AC power supply through the first LC circuit. The second switch is connected in series to the first switch. The smoothing capacitor is connected in parallel to a series circuit of the first switch and the second switch. The second LC circuit is connected between a connection point between the first switch and the second switch and a load. The controller outputs a first pulse signal to the first switch when a voltage polarity of the AC power supply is positive, and outputs a second pulse signal to the second switch when the voltage polarity is negative.

Abstract: The power supply comprises a bridge rectifier connected to an AC source; a boost converter series-connected to the bridge rectifier comprising an inductance coil; a filter capacitor series-connected to the boost converter; a DC/DC converter connected to a load; a hold-up-time enhancer connected to and positioned between the filter capacitor and the DC/DC converter; and a virtual by-pass system parallel-connected to the hold-up-time enhancer comprising an induction coil inductively coupled to the inductance coil of the boost converter. As such, voltage is induced on the induction coil by the inductance coil in the boost converter and the virtual by-pass system parallel-connected to the hold-up-time enhancer is thereby turned on and off.

Abstract: A power conversion system with zero-voltage start-up mechanism and a zero-voltage start-up device are disclosed. The system includes a power conversion circuit, a power factor correction unit, a storage capacitor, a storage switching unit, and a zero-voltage detection module. The storage switching unit is serially connected with the storage capacitor, and particularly controlled by the zero-voltage detection module. The zero-voltage detection module detects a timing as an input voltage is at low level, and then outputs a control signal to turn on the storage switching unit. Therefore, the present invention assures that the power conversion system is turned on when the input voltage is at the low level, in order to suppress the system from a surge current.

Abstract: In a switching power source, in a state where a second voltage smaller than a first voltage is output from an output unit by intermittently driving a switching unit, the switching unit changes a number of driving times of the switching unit for each driving cycle when the switching unit is intermittently driven.

Abstract: Provided is a power supply apparatus with low power in a standby mode. The apparatus includes a voltage multiplier configured to multiply an input voltage and including a first terminal through which the multiplied voltage is output and a second terminal through which a voltage lower than a voltage of the first terminal is output; a main switch-mode power supply (SMPS) configured to receive the voltage of the first terminal of the voltage multiplier; and a standby SMPS configured to receive a voltage of the second terminal of the voltage multiplier.

Abstract: The invention describes an adaptive circuit (1, 1?) for driving a lower-voltage DC load (2) from a rectified higher-voltage AC supply (3), which adaptive circuit (1, 1?) comprises a charge-storage circuit (21, 21?), which charge storage circuit (21, 21?) comprises a first capacitor (C1) and a second capacitor (C2) connected essentially in series, wherein the second capacitor (C2) is connected at least in parallel with the load (2); and an active switch (22, 22?) realised as a controlled current source (22, 22?) for controlling a load current (Iload) through the load (2) such that, in a closed switch state, load current (Iload) is drawn essentially from the first capacitor (C1) of the charge-storage circuit (21, 21?), and, during an open switch state, load current (Iload) is drawn essentially from the second capacitor (C2).

Abstract: A hold-up time circuit is provided, including: an energy storage capacitor, a step-down circuit and a step-up circuit. A first and a second input end of the step-down circuit are connected to two electrodes of an input power supply. A first output end and a second output end of the step-down circuit are connected to two electrodes of the energy storage capacitor. When the input power supply is normal, the step-down circuit is configured to perform reduction processing on an input voltage of the input power supply, and the energy storage capacitor is charged by an output of the step-down circuit. A first and a second input end of the step-up circuit are connected to the two electrodes of the energy storage capacitor. When the input power supply is power-off, the step-up circuit is configured to perform boost processing on an energy storage voltage of the energy storage capacitor.

Abstract: A filter circuit is employed to filter undesirable harmonics in a multi-phase AC input and provide damping for oscillations associated with the filter circuit. The filter circuit includes a damping circuit connected between phases of the multi-phase AC input. The damping circuit including a rectifier for rectifying harmonics in the multi-phase AC input and a single damping resistor connected across the rectifier.

Abstract: Disclosed include switching-mode power supplies and control methods thereof. A disclosed switching-mode power supply is coupled to an input power node and a ground node, comprising a controller, a first inductor, and a bootstrap circuit. The controller is for controlling a power switch coupled to the input power node and a connection node. The controller is powered by the connection node and an operation power node. The first inductor is coupled between the connection node and a discharge node. The bootstrap circuit is coupled between the discharge node, the operation power node and the connection node, to make an operation voltage at the operation power node substantially not less than a discharge voltage at the discharge node. The discharge node is coupled to power an output load.

Abstract: In accordance with an embodiment, a power supply may include a filter stage coupled to an input terminal of a discharge circuit and a supply capacitor coupled to an output terminal of the discharge circuit. In accordance with another embodiment, a method for discharging at least one capacitor includes discharging the at least one capacitor in response to a signal at the input terminal of the discharge circuit being different from a reference signal.

Abstract: An AC-to-DC conversion apparatus is provided, and which includes a first switch-element, an output capacitor and a bridgeless power-factor-correction (PFC) circuit. The bridgeless PFC circuit is coupled to an AC input, and includes a first inductor, a second inductor and a bridge circuit constructed by second to fifth switch-elements. The first switch-element is connected between bridgeless PFC circuit and the output capacitor. Under such circuit configuration and suitable control manner, the common-mode interference in the provided AC-to-DC conversion apparatus is lowered and thus reducing the power loss.

Abstract: First and second opposing ends are formed in a magnetic path forming member on which a power generation coil is wound. A rotating body has a permanent magnet, a first magnetization member and a second magnetization member. When an operating force does not act on an operating member, an end surface of the first magnetization member is opposed to the first opposing end via a gap and an end surface of the second magnetization member is opposed to the second opposing end via a gap. When the operating member is pressed, the rotating body rotates and when the force to the operating member is released, the operating member and the rotating body return. Since the rotating body and the magnetic path forming member do not come into contact with each other, the force required to operate the operating member is relatively weak and large electromotive force can be obtained.

Abstract: First windings of a first common mode transformer and second windings of a second common mode transformer are connected in series via connection lines. The windings are connected to an AC power supply via connection lines. The first windings are connected to a three-phase motor via connection lines, a converter, and an inverter. High-frequency leakage currents flowing in the connection lines are detected as a common mode voltage by a winding for common mode voltage detection. An output voltage is inputted via a filter to a voltage amplifier unit that amplifies the output voltage, and the amplified voltage is applied to a winding via a capacitor in substantially a same direction as a direction of the common mode voltage. As a result, leakage currents are reduced by induced voltages on the windings.

Abstract: According to one embodiment, a power supply device includes a rectifying circuit configured to rectify an alternating-current power supply, a first capacitor configured to smooth a voltage after rectification, and a falling voltage chopper circuit configured to supply electric power to a load. The first capacitor is set to a capacity in which a section where a voltage after smoothing drops to an output voltage to the load is provided in a rectified half period of the alternating-current power supply. The falling voltage chopper circuit includes at least one switching element configured to receive an input of the voltage after smoothing, operate in a section where the voltage after smoothing exceeds the output voltage, and pause in a section of the output voltage and a second capacitor provided on an output side and having a capacity larger than the capacity of the first capacitor.

Abstract: A power converter includes an input stage connected to receive a three phase AC input voltage and to provide multiple DC voltage levels. The power converter also includes an output stage of a plurality of interleaved LLC converters having series-connected inputs coupled to the multiple DC voltage levels and parallel-connected outputs to provide a DC output voltage. Additionally, the power converter includes a balancing circuit interconnected to the input and output stages to provide substantially balanced output currents from the plurality of interleaved LLC converters for the DC output voltage. Methods of manufacturing and operating a power converter are also provided.

Abstract: A method for operating an electrical circuit, in particular of a converter is described. The circuit, in at least one embodiment, includes a line-side converter that is coupled to a capacitor. The line-side converter includes at least two series connections, each including at least two power semiconductor elements, and each of the at least two series connections being connected parallel to the capacitor. The line-side converter is coupled to an energy supply system. The DC voltage that is present at the capacitor is determined. A maximum voltage is predetermined. If the DC voltage present at the capacitor is determined to be greater than the maximum voltage, then at least two of the power semiconductor elements are switched into their conductive state in such a manner that the capacitor is discharged in the direction of the energy supply system.

Abstract: A ground power unit having a power supply unit capable of accepting a wide range of AC input voltages and producing one or more DC power signals for powering components of the GPU is disclosed. In one embodiment, the power supply unit includes a rectifier that converts an AC input power to a DC link power. The power supply unit includes a gate driving circuit that has a power MOSFET transistor which, under the control of a PWM controller, produces a switched DC signal. The DC link power and the output of the gate drive circuitry are provided to a transformer, which modulates the signals and produces a first DC output power signal that is load independent and a second DC output power signal that is load dependent.

Abstract: An exemplary switching branch for a three-level rectifier includes a first diode and a first semiconductor switch connected in series between a positive direct voltage pole and a neutral direct voltage pole, a second diode and a second semiconductor switch connected in series between a negative direct voltage pole and the neutral direct voltage pole as well as a thyristor and a third diode connected in series between a connection point between the first diode and the first semiconductor switch and a connection point between the second diode and the second semiconductor switch in such a manner that a connection point between the thyristor and the third diode is connected to an alternating voltage pole of the switching branch.

Abstract: A control system includes a detection circuit, a control circuit, and a dummy load system. The detection circuit is operable to detect a voltage level change of a direct-current voltage and output an activating signal when detecting the voltage level change of the DC voltage. The control circuit is operable to receive the activating signal. The dummy load system is electrically connected to the control circuit, and the control circuit controls the dummy load system by generating a turn-on signal in response to receiving the activating signal. A dimmer system and a control method thereof are further disclosed in herein.

Abstract: A converter system including a cascade boost converter and inverting buck converter and controller for converting a rectified AC voltage to a DC output current. The system uses inductors and is configured to use a common reference voltage. The controller is configured to control switching of the converters in an independent manner to decouple operation from each other. For example, control pulses for the boost converter may be wider than pulses for the buck converter. The controller may control the boost converter based on constant on-time control and may control the inverting buck converter based on peak current control. The rectified AC voltage may be an AC conductive angle modulated voltage, where the controller may inhibit switching of the inverted buck converter at a dimming frequency having a duty cycle based on a phase angle of the AC conductive angle modulated voltage.

Abstract: The present invention offers a three-phase converter which conforms to the higher harmonics regulations.

Abstract: A three phase full resonant cyclo-converter suitable for converting a three phase AC supply to a DC output. In one embodiment the cyclo-converter consists of two half bridge cyclo-converters driving a resonant circuit. The main switching sequence of the cyclo-converter may consist of a switching sequence in which the phases of a three phase supply are switched in a repeating sequence from the largest to the smallest absolute voltage value of the supply phases.

Abstract: A synchronous rectifier includes a primary rectifier circuit and a secondary rectifier circuit. The primary rectifier circuit is configured to produce first and second half-rectified signals from respective first and second primary voltage outputs of a first transformer winding. The secondary rectifier circuit is configured to rectify a voltage output of a second transformer winding in response to first and second transistor gate inputs. A first buffer driver is configured to receive the first half-rectified signal and to provide a first buffered control signal to the first transistor gate input. A second buffer driver is configured to receive the second half-rectified signal and to provide a second buffered control signal to the first transistor gate input.

Abstract: The input terminals of an energy-scavenging interface are connectable to a transducer including a storage element, and output terminals of the interface are connectable to an electrical load. The interface includes a first switch that is closed to pass current and store electrical energy in the storage element for a first time interval. The first time interval is based on at least one of a first delay proportional to a time constant of the transducer and sensed current flowing through the first switch reaching a first threshold. The first switch is thereafter opened so to permit the stored electrical energy to be delivered through a first current-conduction element for a second time interval. The second time interval is based on sensed current flowing through the first current-conduction element reaching a second threshold. The first current-conduction element may comprise a second switch actuate out of phase with the first switch.

Abstract: Provided is a switching power supply device capable of effectively improving power supply efficiency with a small number of parts. The switching power supply device includes: a switching circuits (S1 to S4) for converting DC input power into AC power, a transformer (T) having a primary winding to which the AC power is supplied, first rectifiers (D21, D22) for rectifying the AC power induced by the secondary winding of the transformer into DC power, second rectifiers (D31, D32) having anodes connected to cathodes of the first rectifiers, and a capacitor (C) connected between the cathodes of second rectifiers and a predetermined potential node and functioning as an auxiliary power source of a predetermined load (F). Surge generated at the cathodes of the first rectifiers (D21, D22) of the secondary side during switching is supplied to the capacitor (C) via the second rectifiers (D31, D32). The load (F) uses power charged in the capacitor as an operation power source.

Abstract: A two-terminal current controller controls a first current flowing through a parallel-coupled load. During a rising period of a rectified AC voltage, when a load voltage does not exceed a first voltage, the two-terminal current controller operates in a first mode. When the load voltage exceeds the first voltage but does not exceed a second voltage, the two-terminal current controller operates in a second mode. When the load voltage exceeds the second voltage, the two-terminal current controller operates in a third mode. When the load voltage drops to a third voltage smaller than the second voltage after exceeding the second voltage, the two-terminal current controller operates in the second mode when a difference between the second and third voltages exceeds a hysteresis band and operates in the third mode when a difference between the second and third voltages does not exceed the hysteresis band.