Electronic flash charging circuit
First Claim
Patent Images
1. An electronic flash charging circuit for a camera having a power source common to a microcomputer that controls a plurality of camera functions and to an electronic flash, the charging circuit comprising:
- booster circuit means for boosting a voltage applied to the charging circuit and charging a main capacitor of the electronic flash, said booster circuit means comprising a blocking oscillator; and
control means for causing said booster circuit means to operate intermittently, thereby intermittently charging the main capacitor;
wherein said control means includes a transistor of which the emitter is connected to an input terminal of said blocking oscillator and the base is fed with a signal changing alternately between a high level and a low level.
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Abstract
An electronic flash charging circuit for use with a camera having a power source common to a microcomputer that controls a plurality of camera functions and to an electronic flash. The charging circuit has a booster circuit for boosting a charging voltage with which a main capacitor of the electronic flash is charged and a controller that causes the booster circuit to operate intermittently, thereby intermittently charging the main capacitor.
16 Citations
11 Claims
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1. An electronic flash charging circuit for a camera having a power source common to a microcomputer that controls a plurality of camera functions and to an electronic flash, the charging circuit comprising:
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booster circuit means for boosting a voltage applied to the charging circuit and charging a main capacitor of the electronic flash, said booster circuit means comprising a blocking oscillator; and control means for causing said booster circuit means to operate intermittently, thereby intermittently charging the main capacitor; wherein said control means includes a transistor of which the emitter is connected to an input terminal of said blocking oscillator and the base is fed with a signal changing alternately between a high level and a low level. - View Dependent Claims (2, 3)
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4. An electronic flash charging circuit for a camera having a power source common to a microcomputer that controls a plurality of camera functions and to an electronic flash, the charging circuit comprising:
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booster circuit means for boosting a voltage applied to the charging circuit and charging a main capacitor of the electronic flash from an initial voltage subsisting in the main capacitor after operation of the electronic flash, to a minimum operating voltage for the electronic flash; and control means for causing said booster circuit means to operate intermittently during charging of said main capacitor from the initial voltage to the minimum operating voltage, thereby intermittently recharging the main capacitor after actuation of said electronic flash. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11)
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Specification