Simplified Block Analysis

TM 9-1270-212-14&P

construction cannot remove all amplitude and phase

represent the errors in azimuth and elevation between the

variations caused by fluctuations in temperature, especially

helmet line of sight (LOS) and the TSU line of sight or

the copper losses which occur as temperature rises,

turret gun line. The four resolvers accomplish this

T h e r e f o r e , t h e r e s o l v e r s i n t h e linkages are

conversion by measuring the elevation and azimuth angular

winding-compensated resolvers. AS compared to a standard

position of the steel fastener on the end of the tubular arm

resolver, a winding-compensated resolver contains an

in relation to the helicopter armament-system axes.

auxiliary winding compensator inserted within the stator

slots. This winding, similar to the stator winding, effectively

(3) The resolvers in the linkage arm gimbals measure

adjusts output voltage so that it is almost in phase with

the azimuth angle and the elevation angle at each end of the

rotor voltage. Because primary copper-loss effects are

arm. The rails must be properly aligned to the

reflected equally to both compensator and rotor windings,

armament-system axes.

the complementary compensator-winding voltage remains

in phase despite frequency and temperature changes. In the

b. Simplified Block Analysis (fig. 1-8).

HSS, the compensator windings supply feedback voltages to

a dual-channel buffer amplifier. Unity gain from amplifier

(1) The diagmm shows a linkage (either one)

input to resolver output is achieved by selection of two

connected to the TSU and the turret. A pair of resolvers in

external resistors for each resolver. These resistors, located

the TSU and the turret, one attached to the elevation gear

in the linkage connector, are factory selected and must not

train and the other attached to the azimuth gear train,

be interchanged. Because compensator and rotor voltages

provide a three-signaI indication of where the TSU or turret

vary simiIarly when temperature and frequency change, the

is pointing. A 10-volt rms signal provides the resolver

feedback loops automatically adjust to compensate for

excitation reference. The three signals, which represent

these variations.

elevation and azimuth coordinates, are connected to

elevation resolver B1 and azimuth resoiver B2, both of

(2) A dual-channel buffer amplifier is associated with

which are on the carriage end of the linkage arm. The

each winding-compensated resolver, so that there are four

signals are transformed by this pair of resolvers and

buffer amplifiers for each linkage. The eight buffer

connected to azimuth resolver B3 and elevation resolver B4,

amplifiers are located in the EIA. (Refer to foldout FO-4 or

both of which are on the helmet end of the arm. The signals

FO-5, sheet 2.) Buffer amplifier A1, A3, A5, and A7 are

are again transformed by this pair of resolvers. The total

associated with the resolvers in the pilot linkage, and buffer

transformation is dependent on the positions of the four

ampiifiers A2, A4, A6, and A8, with the resolvers in the

resolvers. The original three-signal inputs, plus the

gunner linkage. The eight buffer amplifiers are identical and

arm-resolver transformations, produce three signals that

interchangeable. The pilot linkage is connected to EIA

represent the difference (or error) between the linkage

external connector J3, and the gunner linkage, through the

position and the turret or TSU position. These error signals

extension cable, to EIA external connector J4. Connectors

are directed back to the turret or TSU elevation and

J5 through J12 and XA9 through XA13 are internal to the

azimuth drive amplifiers, where the signals cause elevation

EIA.

and azimuth movement until the error signals from the

linkage are nulled.

NOTE

(2) The range component from a linkage connected.

The theory and connections provided in

to the TSU, which is available at winding R2 of resolver B4,

iS terminated in a 200K resistor, since the TSU is a

paragraphs (3), (4), and (5) apply to the pilot

linkages. Use the connector, pin designator, and

line-of-sight device. The range component from a linkage

reference designator to the right of each slash

c o n n e c t e d to the turret i S terminated in a 200K

potentiometer, from which the gunner can select three

(/) in foldout FO-1 and apply the same theory

for the gunner linkages, omitting paragraph (5).

outputs, representing ranges of 500, 1000, and 1500

meters. The selected signal is routed to the turret elevation

drive circuit as a range correction signal.

(3) Refer to the linkage and EIA functional block

diagram (foldout FO-1) and read the notes. The position

inputs to J1-A, -B, and -C can be from the turret or the

c. Functional Block Analysis.

TSU. This discussion assumes the inputs are from the

turret. The three 400-Hz signals between 0 and 10 volts rms

(1) To obtain system accuracy, the transformation

ratio within the resolvers of the linkages must be kept

that represent the position of the turret are designated k, i,

uniform over the wide range of temperatures encountered

and j. The k signal represents the vertical, or elevation,

in military operating environments. Resolver design and

component; the j signal represents the wing, or left and

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