TM
11-6625-3041-30/TO
33A1-8-908-12
1-28. MULTI VDC (A1) FAULT SENSING
General
Each of the four main DC Supplies (+12, +5, -5, and -12v) is
monitored by two sensors, one for a low condition and one for
a high condition. Each sensor operates in the same manner.
Reference
A Reference circuit provides each sensor with a fixed reference
voltage. The circuit consists of a voltage regulator (R91 and
VR12), which provides a constant 5.1V; and a voltage divider
(R34-R35-R36-R37) , which provides the three different reference
voltages applied to the sensor.
Sensors
the reference voltage. The-other input is a voltage derived
from the voltage being sensed. The thresholds are as follows:
*Actual voltage sensed is +1OV for which low threshold is
+7.6 to +9.OV and high threshold +11.2 to +12.6V.
Normally the output from each sensor is high. An out-of-
tolerance voltage input causes the sensor output to go low.