Sharp SF-1014 Service Manual page 111

(8) Toner supply motor drive circuit
IC104 is the motor control IC which drives the toner supply motor with
the pulse signals (TMa, TMb) outputted from the I/O chip.
+5V
TMa
TMb
I/O
R208 R209
47KJ 47KJ
Internal circuit
+5V +24V
2 8
REG
Protection
circuit
(Heat insulated)
9 1
TMa
TMb
Truth value table
Input
TMa TMb
L L
H L
L H
H H
∞
: High impedance
(9) Reset IC (IC113)
1
Outline
The M51953 BL is the most suitable semiconductor IC for detecting
the power voltage to reset the CPU and every type of logic circuit. It is
equipped with the delay circuit to provide delay time just by adding an
external capacitor.
External view 5P5
+24V
IC104
C102
+
2 6
9 8
10UF35V
IN1
1 7 TMa
IN2
5 3 TMb
GND
TA7291S
M
6
TMa
7
3
TMb
5
GND
Output
Mode
TMa TMb
∞ ∞
Stop
H L CW/CCW
L H CCW/CW
L L Brake
5 Output
4 Delay capacity
3 GND
2 NC
1 Power
2
Operation
After td (= 30msec) from when the voltage exceeds 4.25V after power
rising, the output becomes HIGH.
"td" is set by the external capacitor.
R1
R2
1.25V
+24V
M
4.25V
0.65V
H
L
Output not constant
12 – 8
Power
5µA
reference
-
-
+
GND Delay capacity
ta
ta = 30m sec
Output
t
ta
t