摘要:
A discharge lamp lighting device has first switching means for converting AC power into DC power and second switching means for converting the DC power into a high frequency power, the first switching means being driven subsequently to a driving of the second switching means, and the device is arranged for intermittently applying a pulse voltage to a discharge lamp during its dimming lighting, whereby any secondary voltage can be effectively lowered and any flash apt to occur during the dimming lighting can be restrained.
摘要:
The ballast of the present invention includes a DC power supply, an inverter circuit, a load circuit, and an integrated control circuit. The integrated control circuit controls the switching elements of the DC power supply and the inverter circuit. The integrated control circuit includes a first control unit, a second control unit, and a driver circuit. The first control unit generates a first control signal for control of the switching element of the DC power supply. The second control unit generates a second control signal for control of the switching elements of the inverter circuit. The driver circuit provides drive signals for driving each one of the switching elements of said DC power supply and the inverter circuit in accordance with the first control signal and the second control signal. As mentioned above, control circuits for controlling the DC power supply and the inverter circuit are integrated into a single component, the number of components which are mounted on a printed circuit board is reduced.
摘要:
The ballast of the present invention includes a DC power supply, an inverter circuit, a load circuit, and an integrated control circuit. The integrated control circuit controls the switching elements of the DC power supply and the inverter circuit. The integrated control circuit includes a first control unit, a second control unit, and a driver circuit. The first control unit generates a first control signal for control of the switching element of the DC power supply. The second control unit generates a second control signal for control of the switching elements of the inverter circuit. The driver circuit provides drive signals for driving each one of the switching elements of said DC power supply and the inverter circuit in accordance with the first control signal and the second control signal. As mentioned above, control circuits for controlling the DC power supply and the inverter circuit are integrated into a single component, the number of components which are mounted on a printed circuit board is reduced.
摘要:
A camera flash photographing control device having a signal conversion element which generates step wave voltage for which a signal level is gradually varied as time passes, by the operation of a counter which receives a pulse signal. A signal conversion element is operated as an A-D converter in which digital signal output which corresponds to a required signal level is obtained by converting both analogue signals of luminance information of an object and iris information of a photographing lens into said required signal level at the time of light measurement before shutter release. A signal conversion element is operated as a digital-analogue converter in which analogue signal output which corresponds to a pulse signal is obtained by converting the digital signal input of film sensitivity information into a required pulse signal at the time of shutter control after shutter release. Digital signal output from a signal conversion element is stored in memory as camera photographing information at the time of shutter control and analogue signal output from a signal conversion element is sent as information on the degree of flash light emission at the time of shutter control.
摘要:
An adaptor for a camera for operating multiple flash units with a single camera device in which all of the flash units simultaneously emit light. Output signals from each of the flash units indicating that the corresponding individual flash unit is ready to emit light are coupled to corresponding inputs of a logical product circuit such as an AND gate. The single output of the AND gate is coupled to a single corresponding input of the camera device. The X contact of the camera device is coupled in common to the actuation terminals of each of the flash units.
摘要:
A system and method for powering a light-emitting element in an illumination device includes a DC power supply with the light-emitting element coupled across a positive output terminal and a negative output terminal of the DC power supply. A switching element is coupled between the light-emitting element and the negative output terminal. An average current value across the light-emitting element is measured each time the switching element is turned on. A control circuit generates a PWM signal having a pulse width determined based on the calculated average current value and a predetermined target value, and applies the PWM signal to drive the switching element on and off in accordance with the determined pulse width, and a current is generated across the light-emitting element.
摘要:
A lighting device reliably detects a status (i.e., existence or absence) of a load connection, and enables or disables power output based on the detected load connection status. The device includes a DC-DC converter having input and output terminals, and a DC current conducting element coupled across the output terminals. A load terminal is also coupled across the output terminals and configured to receive an LED unit. A load detection circuit coupled between an input terminal and the load terminal detects the connection status of an LED unit via a DC current passing through the load terminal, and controls a switching operation of the DC-DC converter based on the detected connection status. A diode coupled between the load terminal and the DC current conducting element blocks a DC current path from the input terminals to the load detection circuit through the DC current conducting element.
摘要:
An LED driver circuit prevents an increase in output voltage of a DC/DC converter in an open circuit condition associated with removal or failure of an LED lighting device. A DC power source provides a first DC voltage across positive and negative voltage rails. A DC/DC converter includes a switching element which when turned ON/OFF provides a second DC voltage across first and second ends of a capacitor which further define first and second LED lighting device connection terminals. A control circuit, upon receiving a drive power signal, turns ON/OFF the switching element to provide constant current control. A power supply circuit is coupled between the second LED lighting device connection terminal and the negative voltage rail and generates the drive power signal to the control circuit during a detected lighting condition. The power supply circuit further disables the drive power signal during a detected open circuit condition.
摘要翻译:LED驱动器电路防止在与LED照明装置的去除或故障相关的开路状态下DC / DC转换器的输出电压增加。 直流电源在正负电压轨上提供第一直流电压。 DC / DC转换器包括开关元件,其在接通/断开时提供跨越电容器的第一和第二端的第二DC电压,其进一步限定第一和第二LED照明器件连接端子。 控制电路在接收到驱动功率信号时,将开关元件接通/断开,以提供恒定的电流控制。 电源电路耦合在第二LED照明装置连接端子和负电压轨道之间,并且在检测到的照明条件期间产生到控制电路的驱动电力信号。 在检测到的开路状态期间,电源电路进一步禁止驱动电力信号。
摘要:
This invention relates to a method of sending and receiving signals when taking photographs with flash by exchanging information obtained on the camera side and the flash side and flash device for this method.Its aim is to take photographs with flash avoiding mutual interference between the camera signal and flash signal through control of the light emission on the flash side and by stopping the transmission of the flash signal to the camera side, while sending camera signal from the camera side to the flash side when sending flash signal generated on the flash side to the camera side.
摘要:
The aperture value in a camera having a flash unit is controlled by a frequency signal from the flash unit. The frequency of the signal is variable in accordance with the light emission characteristics of the flash unit.