Ziatech Corporation ZT 8809A, Руководство по эксплуатации

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Theory of Operation
To detect AC power failure, the ZT 8809A may use any AC converter
that provides transformer isolated AC voltage of no more than
30 VAC from the same source that provides power to the STD
system. The detection circuitry on board the ZT 8809A is calibrated
at the factory to generate an interrupt at 95 VAC RMS with the
optional transformer available from Ziatech. If you use a different
wall transformer,
the following calibration sequence must be
followed.
1. Turn off power to the ZT 8809A.
2. Connect an oscilloscope or logic probe to the W1 jumper post
closest to the capacitor C1 at the card ejector.
3. Connect the wall transformer (maximum 30 VAC) to the AC
input of the ZT 8809A at connector J5 and the output of a
variable AC power supply (Variac).
4. Turn on the Variac and adjust the output voltage to 95 VAC.
5. Turn on the ZT 8809A and adjust the potentiometer R1, located
just next to jumper W1, clockwise until the oscilloscope or logic
probe measures a logical 1.
6. Adjust potentiometer R1 counterclockwise until the oscilloscope
or logic probe measures a change from the logical 1 to the
logical 0 state.
7. Increase the output voltage of the Variac to 115 VAC.
8. Decrease the output voltage of the Variac to the point that the
oscilloscope or logic probe measures a change from a logical 1
to a logical 0. At this point the output of the Variac should be
95 VAC. Repeat the above procedure if the voltage is off by
more than
±
2 V.
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