Machine Control Board
Machine Control Board
Table 7-1.
Irrigation pump voltage steps
7-4
Introduction
The Machine Control board resides in the control panel assembly along with the
Display board. The Machine Control interfaces with the ultrasonic section of the
display and keypad. It also interfaces to the solenoid valves, pumps, and the
ultrasonic drive circuitry. This description presents the Machine Control
schematic. Refer to the Schematics Supplement.
Irrigation Pump
A resistor divider and operational amplifier network establishes control for the
irrigation pump. The programmable logic device (PLD) sets the levels. The
signals are optically isolated and sent as inputs to a quad analog switch. The
analog switch selects gain resistors for an op amp, which is amplifying a dc level.
The op amps output drives a pump speed controller (off board) which has a
greater than 10k ohm input resistance.
The 5-bit output signal range for the irrigation pump is approximately
0 to 5V DC. The following table shows the irrigation steps:
irrigation step
display
desired voltage
1
2
3
4
5
6
7
8
9
10
ff max
Suction Pump
CUSA EXcel Ultrasonic Surgical Aspiration System Service Manual
setpoint
0.28
2
0.45
3
0.61
4
0.78
5
0.93
6
1.1
7
1.3
8
1.45
9
1.6
10
1.75
11
5
16
5v_x = 5.6v
theoret v
0.32
0.47
0.63
0.79
0.95
1.11
1.27
1.43
1.59
1.75
4.98