摘要:
A method for stabilizing brightness of a cold cathode fluorescent lamp includes receiving currents from two ends of the cold cathode fluorescent lamp and providing a current for the cold cathode fluorescent lamp according to a lower current of the currents received from the two ends of the cold cathode fluorescent lamp.
摘要:
A switching power converter for converting an AC power into a DC power. The converter includes a transformer, a charge storage unit, a synchronization signal generator, and a switch element. The transformer includes a primary side coil and a secondary side coil, and the primary side coil generates an induced voltage at the secondary side coil according to AC power. The charge storage unit charges according to the induced voltage and outputs a DC power. The synchronization signal generator generates a synchronization signal according to the induced voltage. The synchronization signal is the first value when the induced voltage is positive and is the second value when the induced voltage is negative. The switch element, serially connected to the secondary side coil and controlled by the synchronization signal, is turned on when the synchronization signal is the first value and is turned off when otherwise.
摘要:
A power system having a power saving mechanism includes a voltage regulator, a power input module, and a switching signal generation unit. The voltage regulator performs a regulation operation on a first voltage for generating a second voltage. The power input module includes a transformer, a rectifying unit, a switch, and a switch control unit. The rectifying unit together with the transformer is put in use for converting an input voltage into the first voltage. The switch is employed to control a current flowing through the primary winding of the transformer. The switch control unit generates a control signal for controlling the switch according to a switching signal. The switching signal generation unit is utilized for generating the switching signal to disable the switch control unit during an energy transfer disable interval so as to decrease the first voltage from a first predetermined voltage to a second predetermined voltage.
摘要:
A monitor and a power circuit thereof. The monitor includes a power circuit and a lamp. The power circuit driving the lamp to emit light includes an AC-to-DC converter, a transformer, a switch, a pulse width modulation (PWM) unit, a DC filter and a Royer circuit. The AC-to-DC converter receives a first AC voltage and generates a first DC voltage. The transformer has a secondary side coil for generating a second AC voltage, and a primary side coil, which has one end for receiving the first DC voltage and the other end coupled to a low potential through the switch. The PWM unit controls the switch to turn on to adjust the second AC voltage. The DC filter filters the second AC voltage into a second DC voltage. The Royer circuit generates a third AC voltage for driving the lamp to emit the light according to the second DC voltage.
摘要:
A method for stabilizing brightness of a cold cathode fluorescent lamp includes receiving currents from two ends of the cold cathode fluorescent lamp and providing a current for the cold cathode fluorescent lamp according to a lower current of the currents received from the two ends of the cold cathode fluorescent lamp.
摘要:
A monitor and a DC/AC converter thereof are provided. The monitor includes a lamp and a DC/AC converter. The DC/AC converter includes a pulse width modulation (PWM) unit, a DC/DC converting unit and a Royer circuit. The PWM unit is used for outputting a PWM signal whose pulse width is determined by a potential signal. The DC/DC converting unit receives and converts the first DC voltage to a second DC voltage whose potential is determined by the PWM signal. The Royer circuit generates an AC voltage to the lamp according to the second DC voltage. The DC/AC converter determines the potential of the AC voltage according to the potential signal. When the DC/AC converter operates in burst mode, the potential signal is alternated between a high potential and a low potential, such that the AC voltage outputted is in burst mode.
摘要翻译:提供了一种监视器及其DC / AC转换器。 显示器包括一个灯和一个DC / AC转换器。 DC / AC转换器包括脉冲宽度调制(PWM)单元,DC / DC转换单元和Royer电路。 PWM单元用于输出脉冲宽度由电位信号决定的PWM信号。 DC / DC转换单元接收并转换第一DC电压至其电位由PWM信号确定的第二DC电压。 罗伊电路根据第二直流电压向灯产生交流电压。 DC / AC转换器根据电位信号确定交流电压的电位。 当DC / AC转换器以突发模式工作时,电位信号在高电位和低电位之间交替,使得输出的AC电压处于突发模式。
摘要:
A power adaptor includes an inverter, a feedback circuit, a detecting unit, and an adjusting unit. The inverter is configured to convert an input voltage into an output voltage according to a power conversion ratio and adjust the power conversion ratio according to a feedback voltage. The feedback circuit is configured to provide the feedback voltage by voltage-dividing the output voltage according to a specific ratio. The detecting unit is configured to detect a load of an output end of the power adaptor. The adjusting is configured to adjust the specific ratio according to the loading variation of the load.
摘要:
An apparatus for driving a light tube and the method thereof. The driving apparatus includes a delay unit, a first logic device, a second logic device, and a transformer. The delay unit receives an input signal and a voltage control signal, and outputs a delay signal. The first logic device processes a first operation on the input signal and the voltage control signal, then outputs a first signal. The second logic device processes a logic operation on the input signal and the voltage control signal, and then outputs a second signal. The two ends of the primary coil of the transformer are respectively coupled to a first switch and a second switch which are respectively controlled by the first signal and the second signal. The secondary coil of the transformer outputs a driving signal to drive the light tube.
摘要:
A switching power converter for converting an AC power into a DC power. The converter includes a transformer, a charge storage unit, a synchronization signal generator, and a switch element. The transformer includes a primary side coil and a secondary side coil, and the primary side coil generates an induced voltage at the secondary side coil according to AC power. The charge storage unit charges according to the induced voltage and outputs a DC power. The synchronization signal generator generates a synchronization signal according to the induced voltage. The synchronization signal is the first value when the induced voltage is positive and is the second value when the induced voltage is negative. The switch element, serially connected to the secondary side coil and controlled by the synchronization signal, is turned on when the synchronization signal is the first value and is turned off when otherwise.
摘要:
A power adaptor includes an inverter, a feedback circuit, a detecting unit, and an adjusting unit. The inverter is configured to convert an input voltage into an output voltage according to a power conversion ratio and adjust the power conversion ratio according to a feedback voltage. The feedback circuit is configured to provide the feedback voltage by voltage-dividing the output voltage according to a specific ratio. The detecting unit is configured to detect a load of an output end of the power adaptor. The adjusting is configured to adjust the specific ratio according to the loading variation of the load.