JPH0194925U

JPH0194925U -

Info

Publication number: JPH0194925U
Application number: JP19182387U
Authority: JP
Priority date: 1987-12-17
Filing date: 1987-12-17
Publication date: 1989-06-22
Anticipated expiration: 2002-12-17
Also published as: JPH0712979Y2

Description

[Brief explanation of the drawing]

第１ａ図は本考案における電子閃光装置の一実
施例の全体構成を示す回路図、第１ｂ図はその持
続放電禁止回路の具体例を示す回路図、第２図は
第１図の各部電圧波形図である。第３ａ図および
第３ｂ図は従来回路を示すブロツク図、回路図で
ある。３：ＤＣ―ＤＣコンバータ、９：主コンデンサ
、１２：発光開始スイツチ、１４：閃光放電管、
１５：主サイリスタ、１９：転流コンデンサ、２
１：転流サイリスタ、２４：持続放電禁止回路、
２５：調光回路、１０１：第１のスイツチングト
ランジスタ、１０２：抵抗、１０３：ダイオード
、１０４：持続放電禁止用コンデンサ、１０７：
第２のスイツチングトランジスタ。 Fig. 1a is a circuit diagram showing the overall configuration of an embodiment of the electronic flash device of the present invention, Fig. 1b is a circuit diagram showing a specific example of the sustained discharge prohibition circuit, and Fig. 2 is a voltage waveform of each part of Fig. 1. It is a diagram. FIGS. 3a and 3b are block diagrams and circuit diagrams showing conventional circuits. 3: DC-DC converter, 9: Main capacitor, 12: Light emission start switch, 14: Flash discharge tube,
15: Main thyristor, 19: Commutation capacitor, 2
1: Commutation thyristor, 24: Sustained discharge inhibition circuit,
25: Dimming circuit, 101: First switching transistor, 102: Resistor, 103: Diode, 104: Capacitor for inhibiting sustained discharge, 107:
Second switching transistor.

Claims

[Claims for Utility Model Registration] (1) A DC-DC converter that boosts a low-voltage power supply, a main capacitor that charges the voltage boosted by this DC-DC converter and stores luminous energy, and a charging charge of the main capacitor. A flash discharge tube that emits light from the flash discharge tube, a trigger circuit that triggers the flash discharge tube, a commutation circuit that stops the light emission of the flash discharge tube, and a flash discharge tube that operates in synchronization with the flash light from the flash discharge tube. A dimming circuit that controls the amount of light emitted from the flash discharge tube via the commutation circuit, a voltage detection circuit that detects the voltage of the main capacitor and keeps the voltage of the main capacitor constant, and a voltage detection circuit that controls the charging of the main capacitor. In an electronic flash device having an external power supply terminal enabled by supply from an external power source and a sustained discharge prohibition circuit for preventing connection discharge of the flash discharge tube, the sustained discharge prohibition circuit is configured to prevent connection discharge of the flash discharge tube. a first switch means that is turned on when the light is emitted and turned off when the light is not emitted; a sustained discharge prohibition capacitor; and when the first switch means is turned on, the capacitor for the sustained discharge prohibition circuit is supplied with current through the first switch means. a charging path that discharges the charge of the sustained discharge inhibiting capacitor when the first switch means is turned off;
When the switch means is turned off, it is turned on by the charged charge of the sustained discharge inhibiting capacitor, and the second switch means supplies the charged charge of the sustained discharge inhibiting capacitor to the commutation circuit to inhibit sustained discharge of the flash discharge tube. 1. A sustained discharge prevention electronic flash device, characterized in that it has a switch means. (2) The sustained discharge prohibition capacitor is charged to a predetermined voltage before the main capacitor is completely discharged, and the second switch means is configured to charge the sustained discharge prohibition capacitor to the predetermined voltage, and the first switch The sustained discharge prevention electronic flash device according to claim 1, characterized in that the device is turned on only when the means is off.