Technical Description
Technical Handbook
019722-101 Rev. 05
20
SC-350/360
Fuses
A fuse for the 24 volt line is located on the PSU board. A main fuse
is located in the mains socket.
Caution!
If a machine unintentionally is connected to a higher mains voltage
this will not only cause the fuse on the PSU to blow, it will also cause a
36 V zener diode on the small AUX interface board to blow.
The motor has a thermal fuse that is activated when the motor is
overloaded. The fuse cuts the power to all units except the
transformer.
Caution!
The machine must be disconnected from the power supply for about
20 minutes to enable the fuse to return to its normal position.
Regulators
The IC1 is a switched regulator gene5 V for the CPU board.
A reference voltage of 1.25 V is located on the IC1 pin 8.
Triacs
The PSU board has three triacs:
• SCR1 switches on the hopper motor.
• SCR2 switches on/off the main motor in its forward direction.
• SCR3 switches on/off the main motor in its reverse direction.
The opto switches OP1 OP2 and OP3 control the triacs. They ensure
that no noise is generated by the triac.
Miscellaneous
The transistor T1 activates the solenoid which is connected to the
PSU board via the CPU board.
6.5 Serial Interface
The serial interface board is fitted on the rear of the machine. It
generates the signal levels needed for communication according to
RS232C.
On the IC1, pin 2 there should be +10 V, and on pin 6 about -10 V.
The board also has ESD protection components.
