Cooling Pump; Suction Valve; Amplitude Control - Valleylab CUSA EXcel-8 Service Manual

Machine Control Board
Cooling Pump
Cooling pump control results from the same kind of operation as
irrigation and suction pump control. The 3-bit D/A output signal range
for the cooling pump is approximately 0 to 5.1V DC. The following table
shows the cooling steps:
Table 7-3.
Cooling pump voltage steps cool step +5v_x= 5.6v
desired voltage setpoint theoret v
1 0.73
2 1.46
default 2.208 3 2.19
4 2.94
5 3.67
6 4.40
max 5.152 7 5.13
Suction Valve
Optically isolated digital circuits control the suction valve. When current
moves through an internal LED, the output open collector transistor is
saturated. The pull-up resistors and the controlling hardware reside on |
the destination board.
Amplitude Control
The handpiece amplitude control circuit, a 4-bit D/A output signal range
for the handpiece control, operates from approximately 0 to 10V DC. The
op amp maximum supply voltage is 15V, so two diode drops prevent the
op amp from seeing the full 15V from the supply. The following table
shows the handpiece amplitude control steps:
Table 7-4.
Handpiece amplitude control amp step desired voltage D/A code theoret v
voltages
1 1.00
è 2.01
2.208 3 3.01
4 4.04
7-6
ud