ELECTRONIC FLASH DEVICE

• Main Author: ISHIKAWA MOTOHIRO
• Format: Patent
• Language: English
• Published: 06.09.2007
• Subjects: ACCESSORIES THEREFOR; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USINGWAVES OTHER THAN OPTICAL WAVES; APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FORPROJECTING OR VIEWING THEM; CINEMATOGRAPHY; ELECTRIC HEATING; ELECTRIC LIGHTING NOT OTHERWISE PROVIDED FOR; ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; ELECTROGRAPHY; HOLOGRAPHY; PHOTOGRAPHY; PHYSICS

PROBLEM TO BE SOLVED: To limit a strobe charge current at low temperatures by arranging a temperature sensor in a circuit in order to improve the service life of a battery at low temperatures, in a strobe circuit. SOLUTION: In relation to a time constant of oscillation determined by C and R in the past, a thermistor is added. When it is assumed that the resistance of the thermistor is R(t), the time constant is obtained from C×R×R(t). Since the resistance R(t) becomes sufficiently greater than R at low temperatures, the time constant can be obtained from CR(t), the time constant increases as compared with that at ordinary temperatures, an oscillation frequency is lowered and a current flowing to a transformer is reduced. COPYRIGHT: (C)2007,JPO&INPIT