VC3500/VC3700 Troubleshooting Manual
Valco Cincinnati
Page 13
Glue Pressure Pushbutton/toggle Interface
A demand for increase in glue pressure enters the board at connector J2, pin 2. This active-
high signal is presented to the digital pot U1, pin 2 to place it in an "UP" mode. At the same
time, the active-low signal at U1, pin 7 enables the chip to count pulses at pin 1 from a free-
running oscillator circuit. The resistor in the digital pot provides the negative feedback from
op-amp U4, pin 14.
Speed Tracking Circuit
Encoder pulses from connector J1, pin 10 are input to Frequency-to-voltage converter U3 at
pin 6. Op-amp output U4, pin 14 allows this voltage (and the glue pressure) to be varied by
adjusting Digital Pot U1. Op-amp output U4, pin 1 acts as an adder to add an offset
(determined from setting of Jumper JP1) to be added to the previous op-amp stage. This
provides a low limit to the drive signal for the EPC-6, therefore a low limit to air pressure
that supplied to the glue source.
Pressure Bar Graph Driver
The buffered analog signal from the pressure transducer on the EPC-6 is present at connector
J2, pin 4. Op-amp output U4, pin 7 provides zero-adjust of the LCD/Touchscreen pressure
bar graph through potentiometer P1. This analog output signal is sent to the CPU board,
converted to a digital signal, then is used by the 68000 main processor to display the glue
pressure bar graph.
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 ...