Olivetti d-Copia 300 Service Manual page 290

2FD/2FF/2FG
Developing bias parameters
For the bias to the developing sleeve, an alternating
current (AC) is applied. Parameters for the
developing bias are shown below.
V Duty
Vp-p: Difference between the maximum and the
minimum of applied voltage
1.72 kV (fixed)
Vf: Frequency
Typically 2.6 kHz. This value varies depending on the
preset value of the drum surface potential and the
Vo
environmental correction. (Can be adjusted with the
Vdc
Vp-p
maintenance item U101.)
VL
Duty: Ratio of time where + voltage is applied in a
0
cycle
Typically 45%. This value varies depending on the
preset value of the drum surface potential and the
environmental correction. (Can be adjusted with the
maintenance item U101.)
Vde: Developing shift bias potential
160 V (Can be changed to 180 V with the
Vf
maintenance item U101)
Supplementation
V0: Drum surface potential on non-image area (area
not exposed to light)
VL: Drum surface potential on image area (area
exposed to light)
Figure 2-1-19 Developing bias waveform
2-1-16