CHAPTER 2. OPERATING INSTRUCTIONS - TM-55-4920-415-13-P0008

TM 55-4920-415-13&P

CHAPTER 2

OPERATING INSTRUCTIONS

SECTION I. INSTRUMENTS AND CONTROLS

2-8. Leveling Pad. Four leveling pads (3, Figure 1-1)

2-1. General. Information relative to the location and

located on the base (16) are used to level the tester.

function of the controls and instruments necessary to

operate the gyro tester is contained in this section. A

close-up picture of the control panel (29) is shown in

2-9. Circular Level. Two circular levels (4, Figure 1-1)

Figure 2-1.

and (9) are used as visual aids in leveling the unit.

2-2. Rotation Switch. This is a three position toggle-

2-10. Indicator Light.

type switch located on the control panel (22, Figure 2-1)

which energizes, de-energizes or reverses the direction

a. When ac power has been applied to the unit

of the drive motor (10, Figure 1-1).

indicator light (27, Figure 2-1) glows.

b. When ac power has been applied to the vibrator

2-3. Rotational Rate Switch. This four position rotary

motor through application of toggle switch (25,

switch located on the control panel (26, Figure 2-1)

Figure 2-1), indicator light (23, Figure 2-1)

applies ac power to the gyro tester, and at the same

glows.

time, selects the rotational rate for the gimbal ring-fork

assembly in steps of 10, 15, or 20 degrees per second.

2-11. Rotation Rate Adjust Control.

2-4. Vibrator Motor Switch . This two position toggle-

type switch (25, Figure 2-1) located on the control panel

a. Potentiometer (19, Figure 2-1) is used to set the

turns the vibrator motor (8, Figure 1-1) "ON" or "OFF".

20 degrees per second rotational rate of the

gimbal ring-fork assembly.

2-5. Cradle Index Knob. This knob (17, Figure 1-1)

b. Potentiometer (20, Figure 2-1) is used to set the

mounted on the base is used to lock the cradle (15,

15 degrees per second rotational rate.

Figure 1-1) in the horizontal or vertical position.

c. Potentiometer (21, Figure 2-1) is used to set the

2-6. Gimbal Index Knob. This knob (1, Figure 1-1)

10 degrees per second rotational rate.

located on the fork (7) locks the gimbal ring (6) in a

plane either parallel to, or at a right angle to the fork.

2-12. Fuse Holder.

2-7. Fork Index Knob. This knob (14, Figure 1-1) is

a. A 5 ampere fuse in location (28, Figure 2-1)

mounted on the fork and in the engaged position locks

provides electrical protection for the unit from

the gimbal ring-fork assembly in either the 0 degree or

the incoming ac power.

360 degree positions (after one full turn). By pulling the

knob and twisting it one-quarter turn clockwise or

b. A 1 ampere fuse in location (24, Figure 2-1)

counterclockwise, it disengages allowing the fork to turn

provides electrical protection for the vibrator

continuously.

motor.

Figure 2-1. Control Panel.

2-1