(5) Driver circuit (Solenoid)
1. General
It is impossible for the control signal of each load from the CPU to
directly drive the load. The control signal is passed through the driver
IC then to each load.
2. Operation
The driver circuit is composed of two transistors, forming a Darlington
circuit.
In this circuit, a great drive current is obtained from a small input
current (CPU output current). When the driver input voltage is HIGH
(+5V), the transistor turns ON, flowing a current in the arrow direction
to drive the load. When the driver is ON, the driver output pin voltage
is 0V.
(6)
Stepping motor drive circuit
1. General
This driver circuit drives the lens drive motor.
A: Stepping motor phase A coil drive signal
B: Stepping motor phase B coil drive signal
A: Stepping motor phase A coil drive signal
B: Stepping motor phase B coil drive signal
Stepping motor time chart
Drive signal
Lens drive
A
LEMT0
B
LEMT1
A
LEMT2
B
LEMT3
(7) AE (Automatic Exposure) sensor circuit
The AE sensor circuit is composed of the AE sensor PWB which
includes the photo diode and the I-V converting circuit, and the
amplifier circuit on the control PWB.
Operation amplifier A performs I-V conversion of the original density
level (a minute current). Operation amplifier B amplifies the output of
operation amplifier A to the suitable level to input to the CPU.
When SIM 47 is executed, the AE gain signal (AEG0
∼
AEG2) are
switched to automatically set the amplifying level.
The AE operation is performed by the software in the control PWB.
When an incident light enters the sensor, a voltage according to the
light intensity is inputted to the CPU, which compares the input volt-
age and the copy lamp applying voltage to control the copy lamp
voltage so that the exposure level meets the original density.
LOAD
+24V
CPU
output
B
B
+24V
Phase B
Phase B
A
A
+24V
Phase A
Phase A
A
A
B
B
7
6
5
24V
4
LM324
+
-
B
1KJ
AES
HZS583
330KF
12KF
2KF
10KJ
R239
2
3
1
+
-
200KJ
33PF
LM324
200KJ
PDK
PDA
22000PF
AN3
CPU
CLPWM
AGE2
AGE1
AES1
A
2KF
2KF
AGE0
DTC114EK
X 3
AE sensor PWB
12 – 7
www.freeservicemanuals.info
1/11/16
Published in Heiloo, Holland.