VC3500/VC3700 Troubleshooting Manual
Valco Cincinnati
Page 14
LED board - 151xx365 (VC3500) or 151xx406 (VC3700)
(Reference Schematic 999xD151-201 or 999sD151-218)
Service Access Points
Connectors
CO1
VC3500: Connection to Interface board via a 30 pin ribbon cable.
VC3500: Connection to Interface board and Glue Inspection Board via a
40 pin ribbon cable. This cable is split with the first 10 conductors
going to the Glue Inspection Board.
J2
Connection for 17 VDC supply voltage from the Power Supply board.
J3, J4
Connection to Analog daughter board.
J5
Connection to EPC via a four conductor cable.
J6, J7
Connection for front panel Channels 1 & 2 Enable switches.
J8, J9
Connection for front panel Channels 3 & 4 Enable switches. VC3700
only.
J10
Connection for front panel Pressure Adjust switch.
Schematic Description
5v Logic Supply
A 7805 (U6) provides a regulated 5v supply for logic on this board. Resistor R2 is in series
with the regulator to provide some voltage drop to decrease the power dissipation across the
regulator.
12v EPC-6 Supply
A 7812 (U7) provides the supply voltage for the EPC-6.
Valve Enable Switch Inputs
Valve enable and purge signals for four channels are conditioned by schmitt trigger gates
from U2 and U3 before being sent to the Interface board.
LED Drivers
In general, ULN2803's are used to drive the LED light bars for the front panel indicators.
These are merely DIP-packaged npn transistors.
The signal for the Encoder LED light bar is first sent to the monostable multivibrator U8
(74HC221) to provide a blink for every encoder level change (or transition).
Encoder Buffer
The encoder signal from connector CO1, pin 4 is buffered and level-shifted from 5v to 12v
by npn transistor Q1 before it is sent to the Analog board.
Summary of Contents for VC3500
Page 1: ...VC3500 User s Manual Software Version 3 X Manual Number MCO35 Manual Release Date July 1999 ...
Page 19: ...Installation VC3500 User s Manual Valco Cincinnati 16 Figure 8 Internal Connections Diagram ...
Page 88: ...VC3700 User s Manual Software Version 3 X Manual Number MCO34 Manual Release Date July 1999 ...
Page 181: ...VC3500 VC3700 Troubleshooting Manual Manual Number MC048 Release Date May 1999 ...
Page 185: ...VC3500 VC3700 Troubleshooting Manual Valco Cincinnati Page 1 System Level Documents ...