摘要:
A discharge lamp system includes an AC power source, a rectifier, a power factor correction (PFC) circuit, a half-bridge circuit, and a controller. The AC power source provides an AC power. The rectifier converts the AC power into a DC power. The PFC circuit is electrically coupled to the rectifier and is configured for generating an output voltage. The half-bridge circuit is electrically coupled to the PFC circuit and a discharge lamp, and is configured for converting the output voltage into a voltage required by the discharge lamp. The controller is electrically coupled to the PFC circuit and the half-bridge circuit, and includes a timer for counting time, in which the controller controls the output voltage of the PFC circuit in accordance with a time period counted by the timer.
摘要:
A lighting apparatus includes a lighting unit, a converting circuit, a sensing circuit, and a current control circuit. The lighting unit includes at least one light emitting diode and a switching device connected with each other in series. The converting circuit has an output end electrically connected to the lighting unit for driving it. The sensing circuit includes a sensing element capable of indirectly detecting the current flowing through the light emitting diode and outputting a feedback signal. The current control circuit receives a reference current, the feedback signal and a dimming command, and sends a dimming control signal to the lighting unit and a current control signal to the converting circuit, capable of controlling the amplitude of the current flowing through the light emitting diode.
摘要:
A discharge lamp system includes a discharge lamp; a power supply device for providing DC input voltage and current; a converter connected to the discharge lamp and the power supply device for providing power for the discharge lamp; a DC input voltage detecting unit connected to the power supply device for detecting the DC input voltage; a DC input current detecting unit connected to the power supply device for detecting the DC input current; a lamp state detecting unit for detecting a signal responsive to the lamp state; a controller connected to the converter, the DC input voltage detecting unit, the DC input current detecting unit and the lamp state detecting unit for controlling the discharge lamp according to the signal responsive to the lamp state, the DC input voltage and the DC input current. A controlling method for the discharge lamp system is also disclosed herein.
摘要:
A ballast circuit is provided. The ballast circuit comprises a first lamp set, a second lamp set, a detection circuit, and a latch circuit. The first lamp set comprises a first inductor and a plurality of containing areas. The second lamp set comprises a second inductor and at least one containing area. The detection circuit is configured to receive a direct current (DC) voltage and coupled to the containing areas of the first and second lamp sets so that the detection circuit, the first inductor, the second inductor, and a plurality of lamps contained in the containing areas are in a series connection and generate a first signal. The latch circuit is coupled to the detection circuit and configured to selectively start in response to the first signal.
摘要:
A voltage regulation circuit includes a voltage conversion module, an LED driving module and a control module. The voltage conversion module is operable to receive and convert the first voltage to a second voltage. Each LED driving loop of the LED driving module has a current regulator and an LED string. The control module is operable to output a control signal according to the received input signal which reflects the current flowing through the LED driving module. The voltage conversion module regulates the second voltage according to the control signal, such that the regulated second voltage still keeps the brightness of the LED string of each LED driving loop unchanged.
摘要:
The invention discloses a driving circuit structure for driving light-emitting loads. The driving circuit structure may include a power supplying device, a signal processing device and an impedance balancing device and a dimming control unit. The power supplying device is used for supplying an alternating current power supply. The signal processing device is used for converting the alternating current power supply into a direct current power supply, so as to drive the light-emitting loads. The impedance balancing device is used for balancing an alternating current magnitude of the alternating current power supply, so as to stabilize a direct current magnitude of the direct current power supply for driving the light-emitting loads. The dimming control unit is capable of controlling output luminance of the light-emitting loads.
摘要:
A method and a device for controlling a discharge Lamp, and a discharge lamp system are disclosed herein. The method includes the operations of: when the lamp current changes, determining a percentage of change of the lamp current according to a synchronous signal and obtaining a second lamp current after a discharge lamp current changes according to the percentage of change of the lamp current and a first lamp current; obtaining a modulating signal according to a current difference between the first lamp current and the second lamp current; and generating a pulse voltage signal according to the modulating signal. The pulse voltage signal transits from a first voltage to a second voltage during the time period when the lamp current is transited from a first lamp current to a second lamp current during a transition time.
摘要:
An electronic ballast includes an inverter circuit, a variable inductor unit and a control circuit. The variable inductor unit is electrically coupled between the inverter circuit and an illumination device. The control circuit controls the variable inductor unit according to an operation mode of the inverter circuit such that an equivalent inductance of the variable inductor unit has a variation fed back to the inverter circuit, to further change the operation mode of the inverter circuit. An illumination apparatus and a method for protecting the electronic ballast are also disclosed.