TM 11-5820-890-30-4
2-5.
POWER SUPPLY (1A3). Continued
The power supply outputs are over-current protected.
If an output is shorted to ground, the power supply will
shut down.
CAUTION
The power supply will not be damaged if an output is shorted. However, other modules in the RT
may be damaged if this occurs.
Exercise caution when troubleshooting the RT.
The power supply will also shut down if 6 V dc is applied to pin E. This is used by the two-wire interface to turn the
RT off during remote operation.
The other modules in the RT use the output voltages as listed in table 2-2.
Table 2-2. Power Supply Output Destinations
Voltage (V dc)
Destinations (module-pin)
6.75
1A1-A, 1A2-R, 1A4-8, 1A5-H, 1A6-X, 1A7-77, 1A8-P, 1A9-F, 1A10-J,
1A11-X, 1A12-47, J1-KK, J2-E, 1A15-71 , 1A16-14
10.0
3.0
60
-10.0
1A5-B, 1A6-T, 1A7-76, 1A8-Q, 1A9-C, 1A10-F, 1A11-F, 1A12-41, J2-D
1A1-M, 1A9-B,
1A1-Q, 1A11-R
1A5-D, 1A6-Z, 1A7-72, 1A8-O, 1A9-A, 1A10-H, 1A11-D, 1A12-57, J2-A
2-6.
RT CHASSIS (1A17).
The RT chassis includes the front panel, backplane assembly (parent board), and frame. The controls and
connectors on the front panel are used to direct the operation of the RT. The keyboard and SIG displays provide
feedback to the operator. The parent board has 16 sockets for the plug-in modules (1A1 through 1A16). It also
has three connectors that mate with the front panel connectors. It provides most of the module interconnections.
The terminals (E fields) are used as solder points for wires and the flexible circuits that interconnect it to the
system and chassis mounted connectors.
Figure 2-8 identifies the external connectors.
The frame provides physical support for the modules.
The covers must be properly installed and the screws
torqued to provide the required environmental protection.
There is an interlock switch present on the RT chassis.
It protects the COMSEC variable. It is connected to the
COMSEC module at pin 31 through E28. If an RT cover is removed, the switch grounds E28. This will cause the
COMSEC module to zeroize the COMSEC variable. When troubleshooting an RT with its cover removed, the
interlock switch levers must be fully extended to use the CT mode.
2-10
