Stratasys uPrint, Service Manual, Page: 24 / 383

uPrint/uPrint SE Service Manual 2-13
This board provides the power required to run the system. AC line voltage, +5 VDC, +12
VDC, and +24 VDC feed into the PDB. An addi120 VDC input feeds into the PDB for
the support head heater.
AC line voltage comes into the PDB, See Figure 2-5. The voltage is routed through the solid
state relay to an auto switching circuit. The circuit is used to supply the chamber heater
voltage: 240 VAC in series, or 120 VAC in parallel. The solid state relay is controlled by the
controller board, and turns the heater on/off to regulate the chamber temperature. A second
solid state relay provides AC line voltage to the system. It is controlled by the controller
board and safely shuts down the system when the power down switch is turned off.
• The 5 VDC and 12 VDC are used by the controller board, single board computer, and
hard drive. The 12 VDC also powers the filament motors.
• The 24 VDC powers the stepper motors, solenoids, fans, and chamber lights.
• The 120 VDC circuit powers the model heater and a separate 120 VDC supply powers
the support heater.
There are two fuses on the power distribution board.
• Fuse F1 fuses the AC input to the +120 VDC supply.
• Fuse F2 fuses the +120 VDC output.
Chamber Temperature Control
The chamber thermocouple (T/C) connects via the I/O board to the PDB and is sent to the
controller board. The T/C generates a variable low level voltage that depends on the
temperature of the chamber. This analog signal from the chamber thermocouple is amplified
on the I/O board and sent to the PDB. From the amplifier, the signal goes to an A to D
converter in the ColdFire. The controller reads the chamber temperature and turns the
heaters on and off to maintain 77
° C. The chamber fans run continuously when the system is
on. Temperatures can be read on the PDB using a volt meter at test points TP22 for model,
TP20 for support, and TP28 for the chamber NOTE: 10 mV = 1 degree C.
Test Points and LED’s
Test points and LED’s are very useful for troubleshooting the system. The test points and
LED’s are listed below with a brief description. See
Figure 2-6. and Figure 2-7.