TM 55-4920-429-13
Table 2-1. Test Set Controls and Indicators — Continued
CONTROL/INDICATOR
DESCRIPTION
DISPLAY BRIGHT/DIM switch S8
Switch, toggle, 2-position.
Selects BRIGHT or DIM illumination of VDC, VAC, K-OHMS,
STATUS A, and STATUS B indicators and the digital display.
HI and LO terminals TP1, TP2
Binding Posts. Enable connection of external meter to test set for checkout
purposes. Also enable connection of test voltages for testing DISCRETE
SIGNAL MONITOR group and ILCA drive group.
CONTINUITY Group
Four switches used in conjunction with CONTINUITY position of
METER SOURCE switch. Connects various test points of the helicopter to
.
the meter for a continuity measurement.
A SELECT TENS switch S26
Switch, rotary, 1 l-position.
Used in conjunction with the A SELECT UNITS switch to select a test
point in the helicopter and connect it to the high side of the meter.
A SELECT UNITS switch S27
Switch, rotary, 10-position.
Used in conjunction with the A SELECT TENS switch to select a test
point in the helicopter and connect it to the high side of the meter.
B SELECT TENS switch S28
Switch, rotary, 1 l-position.
Used in conjunction with the B SELECT UNITS switch to select a test
point in the helicopter and connect it to the low side of the meter.
B SELECT UNITS switch S29
Switch, rotary, 10-position.
Used in conjunction with the B SELECT TENS switch to select a test
point in the helicopter and connect it to the low side of the meter.
ACTUATOR DRIVE Group
Six switches used in conjunction with ACTUATOR DRIVE position of
METER SOURCE switch.
CCDA switch S3
Switch, momentary.
Selects cw or ccw rotation of CCDA servo motor.
CW. Switch applies 2.5 vat, 400 Hz, 90° lagging (with respect to 115
vac input voltage) to servo motor.
CCW, Switch applies 2.5 vat, 400 Hz, 90° leading, to servo motor.
OFF. Voltage disconnected from servo motor.
DASH switch S4
LCT switch S5
Switch, momentary.
Selects voltage to extend or retract actuator.
EXT. Applies 28 vdc HI to actuator.
RETR. Applies 28 vdc LO to actuator.
OFF. Voltage disconnected from actuator.
Switch, momentary.
Selects extend or retract actuator voltage.
EXT. Applies cyclic trim 28 vdc to actuator extend winding.
RETR. Applies cyclic trim 28 vdc to actuator retract winding.
OFF. Voltage is disconnected.
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