Panasonic DP-MB310EU, Service Manual

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KX-MB2230EU/ KX-MB2270EU/ KX-MB2515EU/ KX-MB2545EU/ KX-MB2575EU/ DP-MB310EU
After setting the above signals, clock signal is supplied from IC300_pin E26 to IC950_pin14.
Whenever clock signal is supplied, current value and direction supplied to Main motor change according to the
excitation type which is determined by above signal levels.
The clock frequency also determines the motor speed.
2. Motor current control circuit
According to the rotation speed, motor current is controlled for appropriate value.
In order to control the motor current, Ref voltage of IC600 is controlled.
When Ref voltage is high, motor current is increased, and the voltage is low, motor current is decreased.
For the control of Ref voltage, PWM pulse is supplied from IC300_pin E25.
PWM pulse is integrated by R958 and C959.
Consequently PWM pulse is converted to DC voltage.
When duty of PWM pulse is high, Ref voltage is increased and when duty is low, Ref voltage is decreased.
3. Solenoid control circuit
The solenoid drive circuit controls Pick up solenoid.
These solenoids and clutch are designed to be driven 24V.
The diodes protect transistors from reverse generated voltage when solenoids are turned off.
4. Explanation of each circuit
5. Timing chart and wave form of Main motors
1. 2-2 phase excitation (Full speed)
(1) Timing chart
OPF PICKUP
MODE IC302_pin6
Solenoid ON High level
Solenoid OFF Low level