Title:
ELECTRONIC FLASHING DEVICE FOR CAMERA
Document Type and Number:
Japanese Patent JPS614465
Kind Code:
A
Abstract:
PURPOSE:To prevent a battery from consuming by stopping the leakage current of a main capacitor in a leakage current preventing circuit when the operation of a DC/DC converter is stopped. CONSTITUTION:A starting switch 13 is closed to flow a base current to an oscillation transistor (Tr)3, a DC/DC converter is started to supply a high DC voltage to a main capacitor 18. The stored charge of the capacitor 18 emits a flashing discharge tube 25 by closing a synchro switch 27. When the voltage arrives at the prescribed voltage when the capacitor 18 is charged, a controlling Tr8 and an oscillation Tr5 are turned ON to set the Tr3 to inoperative state to stop the operation of the converter. In this case, a diode 28 is provided in parallel with a series unit of the Tr3, a stepup transformer 11 and a rectifying diode 14, a voltage higher than the forward voltage drop (approx. 0.6V) of te diode 28 is not applied to the series unit to maintain the Tr3 in completely OFF state.
Inventors:
IKEDA TAKUSHI
IGAWA KAZUO
IGAWA KAZUO
Application Number:
JP12315184A
Publication Date:
January 10, 1986
Filing Date:
June 15, 1984
Export Citation:
Assignee:
CANON KK
International Classes:
G03B15/05; H02M3/338; H05B41/32; (IPC1-7): G03B15/05; H05B41/32
Attorney, Agent or Firm:
Marushima Giichi
Next Patent: AUTOMATICALLY CONTROLLING METHOD FOR POWER FACTOR