Canon NP1550 Service Manual

Also see for NP1550: Service manual

OPERATIONS AND TIMING I3. Developing Bias OperationCOPY START keyWMUPR ON\ V SCRV\ SCRV\WMUP \ STBY INTR SCFW \ SCFW -STR STBYt,AERMain motor (M1 i.Scanner home positionsensor (Q3) signalAC BIAS ON command(ACBON)DC BIAS CONTROL .. * * * * * * . **command (DCBC) W//// '///////// «.'/// ////M'/SSM ) \Figure 3-22The value of the DC BIAS CONTROLcommand and the DC bias are deter-mined by (1) the setting of the COPYDENSITY lever and COPY DENSITYknob, (2) the AE sensor output, and (3)the type of developing assembly installed.The DC bias used at times other thanduring scanning depends on the type ofdeveloping assembly installed.Black developing assembly: Approx.-320V CT unit: Approx. -220VNote;The AC component is added to thedeveloping bias for a CT unit when themain motor is operating.3-24 COPYRIGHT© 199! CANON INC. CANON NP-15S0 REV.1 SEPT. 1992 PRINTED IN JAPAN (IMPRIME AU JAPON)