Gurley Precision Instruments VJ, Руководство пользователя

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There 7700 read head and disk should be installed according to their manual. It may be
necessary to slightly adjust the alignment of the readhead to get the signals in proper
phase shown in Figure 5. The Index signal should be at its minimum or maximum level
when the cosine signal is at it minimum. The simplest ( but not the best way) to make the
adjustment is to slightly move readhead until the LED D1 remains lit without blinking,
when slowly rotating the disk. A better method is to monitor the voltage on Testpoint U
and adjust the read head position until this voltage is at maximum. This pin will be at a
high voltage ( about 3.3V) when Index transitions occur /- 45 degrees of
optimum. You can also observe the signals shown in Figure 5 on an oscilloscope while
adjusting the head.
FIGURE 4: Read head and disk.
FIGURE 5: Analog test point signals. C,S,I, and R. (Reverse Direction show)