Valleylab CUSA EXcel-8 - Power Control Input and Output Signals; Valve Controls

Machine Control Board
amp step desired voltage D/A code theoret v
5
5.04
6 6.05
7 7.05
8 8.11
9 9.11
max 10 10.13
11 11.13
12 12.15
13 13.15
14 14.16
15 15.16
Valve Controls
Optical isolators condition signals to and from the ultrasonics board. The
signals from the footswitch activate fast flush and the ultrasonics, and
indicate whether the footswitch is present. There are several isolated
solenoid valve drivers for controlling tissue release, suction, handpiece
drain, and anti-siphon. The handpiece feedback signals from the
ultrasonics board go through opto-isolators to the PLD. Alert signals such
as cooling out of range, vibration, amplitude, and handpiece not present
also pass through opto-isolators before going into the PLD.
Alay
UND
Power Control Input and Output Signals
When you turn the system power switch on, the softpower circuit, an
input to the PLD, activates all other systems. The shutdown handpiece
bias signal, an output from the PLD, activates the handpiece bias. The
keypad signals (originating at the display board) pass through filters, then
go into the PLD. A power supervisor resets the PLD when the supply
voltage is below specification. The power supervisor input is filtered with
a time constant of 1mS to reduce the possibility of false resets. The crystal
and inverter generate the PLD master clock at 32.768 kHz. The
right angled 10-pin connector allows in-circuit programming of the PLD.
An EE programmable read-only memory (prom) stores initial set points.
CUSA
EXcel-8
System
Service
Manual
1-1