Epson LX-810 Technical Manual page 67

(7)
(V-) thereby drops below
(8)
step (7), COMP 1 output goes HIGH, so that TD voltage VTD gradually rises, in line with the time
constant determined by resistance R59 and capacitance C 15.
The MOS FET gate voltage is maintained at OFF until the value of the T
(9)
The period above, during which
Chopper on time (t2-t3)
o)
(1 When T voltage VTD reaches the COMP2 reference value (2 V), COMP2 inverts, and Q 1 goes
D
on.
(1 1) r When Q1 goes on, the current flow switches from IOFF to I
(12)
On the basis of the time content of motor coil A, loN, after a certain delay, gradually rises in
response to power source voltage Vcc.
As I increases, R30 potential VRS also increases. Until the value of VRS reaches that of
(13)
ON
The period in which
rising from OV to 2V, is equivalent to
from the power source to the motor.
O N
2-31
voltage reaches the
D
T .
O F F
.
O N
.
O N
REV.-A