POWER SUPPLY SYSTEM FOR IMAGING SYSTEM

• Main Authors: TAKAHASHI MASARU, SENMA TOSHITAKA, MORI GORO, YAMAMOTO MASAHIRO, MIYAJIMA MASAMI, ARAKI SHIGEYUKI, ISOBE TAKAHITO, HAYASHI TAKAMASA
• Format: Patent
• Language: English
• Published: 11.06.1992
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

PURPOSE:To lengthen service life of fixing heater and to realize cost reduction by detecting a zero-cross point of AC input voltage when an AC 200V(V2) system is employed as an AC input power supply and performing phase control on the timing at the driving section for the fixing heater so that overvoltage part in the V2 system, which causes shortening of the service life of the fixing heater, is cut. CONSTITUTION:Input voltage from an AC 200V system (V2 system) is subjected to full-wave rectification through a full-wave rectifying circuit 5. AC voltage on the V2 system is detected at the voltage detecting section 12a in a double voltage automatic switch 12 and a transistor 12b is turned OFF. Voltage smoothed through capacitors C1, C2 is employed as the DC voltage in V2 system, full-wave rectified through the full-wave rectifying circuit 5, and applied on a load 6. At that time, a zero-cross point detecting/voltage detecting circuit 18 detects a zero-cross point and simultaneously provides AC voltage of the V2 system to a main control section 19 The main control section 19 then performs phase control so that overvoltage part, causing shortening of the service life of a fixing heater 9, is cut and the voltage part close to the zero- cross point is fed to a heater drive section 13.