Table of Contents
Advertisement
Model 5501A
Maintenance
Table 4-5. Module Adjustment Requirements
A1 Connector Board
Module Replaced
A2 High Voltage
Power Supply
Adjustment Required
A3 Laser Tube Assembly
A4 Beam Splitter Assembly
A5 Lock Reference Board
A6 PZT Power Supply
Laser Current Adj.
Laser Current Adj.
Laser Current Adj.
Reference Threshold Adj.
Reference Threshold Adj.
Reference Threshold Adj.
Photodiode Off-set Adj.
Reference Threshold Adj.
4-17.
ADJUSTMENT PROCEDURES
4-18. The Lock Reference Board Assembly (05501-60204) and theconnector Board Assembly (05501-60201)
are the only 5501A field-adjustable modules. Perform the adjustment procedures either a s a trouble-
shooting check or when certain modules are replaced. Table4-5 lists the 5501A modules and theadjustment
requirements that result from replacement of these modules.
4-19.
Lock
Reference Board Adjustments
4-20. Two adjustments are performed on the A5 Lock Reference Board Assembly: the reference thregold
adjustment; 2nd the photodiode offset adjustment.
4-21.
REFERENCETHRESHOLD ADJUSTMENT. Perform the reference threshold adjustment when trouble-
shooting the laser head or when any of the following assemblies are replaced:
A3 Laser Tube Assembly
A4 Beam Splitter Assembly
A5 Lock Reference Board Assembly
A6 PZT Power Supply Assembly
4-22. The recommended test equipment is:
HP 1707 Oscilloscope or equivalent (ac noise measurments)
HP 5300/5306 Multimeter/Counter (dc voltage measurements)
NOTE
Since the laser head covers are removed, the connector board
safety switch, AlS2, must be closed for the laser head to operate.
4-23.
Make the adjustment according to the following procedure (refer to Figure 4-4):
a.
Block laser beam a s shown in Figure 4-5.
b. Measure peak-to-peak ambient noise at A5TP3 with oscilloscope.
c.
Divide this peak-to-peak value by two.
d. Measure static dc level at A5TP7 with oscilloscope or voltmeter.
e. Record the larger of the values obtained in steps c and d.
f.
Monitor A5TP8 with a DVM or oscilloscope, and adjust the threshold potentiometer,A5R42,for adc
voltage equal to twice the value recorded in step e (see Figure 4-4).
Advertisement
Table of Contents
