Ricoh FW780 Service Manual - Page 234

ELECTRICAL COMPONENT DESCRIPTIONS Name Function Printed Circuit Boards Main Controls all copier functions both directly and through other PCBs. PSU Converts the AC voltage to DC voltage. AC Drive Provides AC power to the fusing lamp and PSU. FL Regulator Stabilizes power to the exposure lamp. Operation Panel Control the operation panel display. Original Feed Drive Controls the rotation of the original feed motor. (A252 only) Index. No. 22 21 15 23 10 46 Lamps Exposure Provides light to reflect the original's image onto the drum (fluorescent lamp). 2 Fusing Provides heat to the fusing unit. 3 Pre-Transfer (PTL) Reduces the charge on the drum surface prior to image transfer. 20 Quenching (QL) Neutralizes any charge remaining on the drum surface after cleaning. 1 Power Packs Charge/Bias/ Grid Power Pack Provides high voltage power for the charge corona, charge grid, and development bias. 19 Transfer/Separation Provides high voltage power for the transfer corona and separation. 16 Thermistors Hot Roller Monitors the hot roller's surface temperature. 8 Pressure Roller Monitors the pressure roller's surface temperature. 11 Thermofuses Fusing Protects against fusing overheat. 9 Heaters Anticondensation Keeps moisture from forming inside the copier (option). 13 Others Total Counter Keeps track of the total length of copies made (Europe) or the total copies made (U.S.A.). 28 Circuit Breaker Guards against voltage surges in the input power. (Europe, Asia)/ 14 Fuse (U.S.A.) A251/A252 1-8 SM