Raytheon SNV-12, Инструкция по установке и эксплуатации

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SNV-12 Operations Manual
3-101
3.13.4 Parallel Control Outputs
The following applies to all SNV-12 parallel control outputs. See the schematic representations
below.
When an output becomes active, the open-drain transistor is turned on; current flows through
the transistor drain to ground, pulling the output low. The maximum voltage that can be
applied to the drain of the transistor at the output connection is +60 VDC. The maximum
continuous current drain for the SVM-1 and CIM-1 is 100 mA, for the CIM-2‟s outputs, the
maximum drain is 50 mA. These outputs are not intended for connection to negative voltages.
The transistors include a parasitic diode; damage may occur if the applied voltage goes
negative by a diode drop and is not current-limited to approx. 10 mA.
For Contact Closure Outputs: The digital outputs consist of an open-channel transistor and are
pulled up to +5 VDC by an internal 47k ohm resistor. These outputs are capable of creating a
“contact closure” indication for positive voltage inputs up to +60 VDC. Unless the internal
pull-up resistor is removed, there will be some current draw through the 47k ohm pull-up for
input logic level above +5 VDC. Alternatively, the output transistor can be used to control an
external relay. Be sure to add a back-biased diode to prevent any reverse EMF problems when
the relay is de-energized. The lower schematic shows the internal relay circuit of the CIM-2.
Figure 3-28 SNV-12 Control Output