Jenway 6300 Ser Man
23
5.1
Power Supplies
See Section 9.1 Power Supply Schematic
The ac mains supply is reduced by the torroidal transformer giving
two low voltage outputs from the secondary windings.
First the 20V ac output from the transformer is rectified by BR1;
the 30V dc output from this rectifier is used as the input to two
L4960 switch mode regulators. (REG1 and REG 3).
Tungsten Lamp Supply
, The output of the switch mode regulator
REG 3 is set to 12V dc by VR1. The 12V output can be reduced to
5.1V by a logic ‘1’ on the gate of TR2. This happens during the
start up tests to reduce the light level for accurate zero order
detection, it can also be manually instigated by pressing the left
arrow key when in the Diagnostics Mode.
Solenoid and Fan Supply
, The output of the switch mode
regulator REG1 is pre-set to 12V. The output to the fan is via Sk1
pin 1 and 2.
The output to solenoid 1 (Dark Shutter) is via SK9 pins 1 and 2
The output to solenoid 2 (IR Stray Light Filter) is via Sk9 pin 3 and
4.
5V Digital Supply
, The other transformer secondary output is half
wave rectified and regulated to 5V by the linear regulator REG 2.
The output is distributed via SK5 pin 1.
Ancillary,
Supplies to the end stop opto-coupler are connected via
SK2 pins 1 to 4.
The RS232 output, accessible through the rear panel on SK6, is fed
from the microprocessor PCB via SK5.
IC1 and 2, TEA3717DP, are the stepper motor drivers, controlled
from the microprocessor PCB via SK5 pins 9 to 12, with outputs to
the motor on SK2 pins 5 to 8.
