Circuit for controlling power source for xenon lamps and signal lighting device adopting the same

摘要

A power source control circuit for a gas discharging tube, for example, a xenon lamp, and a xenon lamp signal lighting device adopting the same, are provided, in which power can be supplied for a relatively long time to a plurality of xenon lamps having a high starting voltage and a large lamp current with a small capacity battery, and a designation of emission and/or a flickering interval of at least one xenon lamp of a multi-color filter type can be easily controlled. The battery operated power source control circuit includes a logic controller for controlling operation of a xenon lamp according to a control process of an analog logic circuit, and a power management circuit for converting a lower voltage supplied from the batteries into a high voltage only when the xenon lamp is activated under the control of the logic controller, whereby a designation of emission and/or flickering intervals of xenon lamps of a multi-color filter type can be easily controlled by a user depressing a button switch to control the power source voltage. The power management circuit includes a DC-to-DC converter for converting a battery DC voltage into a first DC voltage under the control of the logic controller, a voltage converter for converting the first DC voltage into a second DC voltage higher than the first DC voltage under the control of the DC-to-DC converter, a starter for converting the second DC voltage into an alternating high voltage higher than the second DC voltage, to thereby supply the alternating high voltage to the xenon lamp, and a switching device for switching the power source voltage applied from the starter to the xenon lamp under the control of the logic controller. The power management circuit further includes a DC-to-DC converter for maintaining the voltage output from the batteries to be constant, in order to apply a constant voltage to the logic controller since the voltage from the batteries is reduced gradually in use. The logic controller and the DC-to-DC converters are integrated in a single integrated circuit, to realize a custom IC (ASIC), to thereby enable a xenon lamp signal lighting system to be made compact. A small capacity battery can be used for long at maximum.