摘要:
The present invention relates to a switch control circuit, a power factor corrector including the same, and a driving method thereof. According to an exemplary embodiment of the present invention, a turn-on time of a power switch is controlled according to a zero crossing voltage to sense a voltage of both terminals of the power switch, and a turn-off time of the power switch is controlled according to a feedback voltage corresponding to the output voltage. At this time, the switching frequency of the power switch is sensed by the zero crossing voltage and the switching frequency is restricted by a predetermined threshold frequency.
摘要:
The present invention relates to a dimming angle sensing circuit and a driving method thereof.A dimming angle sensing circuit according to an exemplary embodiment of the present invention uses a zener diode. The dimming angle sensing circuit generates a comparison voltage according to a comparison result of a line voltage and a zener voltage. The line voltage is generated from rectification of an AC input passed through a dimmer. The dimming angle sensing circuit generates a sense voltage corresponding to a dimming angle of the dimmer by low-pass filtering the comparison voltage.
摘要:
An exemplary embodiment of the present invention relates to an active damper and a driving method thereof. An AC input passed through a dimmer is transmitted to an active damper through a rectification circuit. The active damper includes a damper resistor connected to the rectification circuit, a damper switch connected to the damper resistor in parallel, and a delay circuit delaying a turn-on time of the damper switch by a predetermined initial period from a turn-on time of the dimmer.
摘要:
An exemplary embodiment of the present invention relates to a switch controller, a method for controlling a switch, and a power supply including the switch controller. According to the exemplary embodiment of the present invention, an AC input passed through a dimmer is rectified such that an input voltage is generated, and the input voltage is transmitted to the power switch. A charging current is generated using a voltage that depends on the input voltage, a zero cross-point at which the input voltage becomes zero voltage is detected using a detection voltage output from a current source, and a reference signal synchronized at the detected zero cross-point is generated.
摘要:
In one embodiment, a power switch driving circuit is provided for a fluorescent lamp ballast. The circuit includes a first power switch driven by a first driver. A controller has a first output terminal for outputting a control signal for controlling the first driver. The first driver includes a first capacitor having a first terminal electrically connected to a control electrode of the first power switch and a second terminal electrically connected to the first output terminal.
摘要:
Embodiments of the present invention relate to a switch control circuit, a switch control method, and a power supply device using the same.Embodiments generate a reference signal according to a full-wave rectification voltage and control a switching operation of a power switch according to a comparing result of a sense voltage corresponding to a current flowing to the power switch and the reference voltage. Embodiments determine whether a line is opened between a first output terminal and a second output terminal of the power supply device using the sense voltage. When the line is opened, Embodiments turn off the protection switch.
摘要:
The present invention relates to a diagnostic device and a lamp ballast circuit. The lamp ballast circuit includes a first power switch, a second power switch, a lamp driven according to switching operations of the first and second power switches, a controller for controlling the switching operations of the first and second power switches, and a diagnostic device. The diagnostic device senses a voltage waveform applied to the lamp to determine an end of lamp life (EOLL) condition and an over-voltage, senses a filament voltage of the lamp to determine a filament connection state of the lamp, and determines an over-voltage of a voltage applied to the controller.
摘要:
A circuit for detecting the end of life of a fluorescent lamp is provided. In this circuit, a rectifier rectifies a voltage signal detected from a ballast. A phase detector detects the phase of the voltage signal and outputs at least one phase detection signal. A signal separator separates the rectified voltage on a phase basis to generate first and second voltage signals in response to the phase detection signal. A first maximum level detector detects the maximum level of the first voltage signal. A second maximum level detector detects the maximum level of the second voltage signal. A first comparison unit compares the first and second maximum levels and detects whether or not the difference is higher than a predetermined allowable level. A controller determines whether or not the fluorescent lamp is at the end of life in response to the detection from the first comparison unit.
摘要:
A power voltage required to operate the switch control device is generated by using full-wave current rectification voltage generated by rectifying an AC input. A zero cross-point is detected when a full-wave rectification voltage is zero voltage by using the power voltage. A reference signal synchronized to the full-wave rectification voltage is generated by using the detected zero cross-point. A switching operation of a power switch is controlled by comparing a reference signal with current that flows on the power switch.
摘要:
The present invention relates to a diagnostic device and a lamp ballast circuit. The lamp ballast circuit includes a first power switch, a second power switch, a lamp driven according to switching operations of the first and second power switches, a controller for controlling the switching operations of the first and second power switches, and a diagnostic device. The diagnostic device senses a voltage waveform applied to the lamp to determine an end of lamp life (EOLL) condition and an over-voltage, senses a filament voltage of the lamp to determine a filament connection state of the lamp, and determines an over-voltage of a voltage applied to the controller.