Figure 2-2.--Wind indicator.

the vane, the rotor on the synchro (directly coupled to

the vane) moves angularly a like amount. The angular

position of the type 18CX4 synchro is sent electrically

to a 18CT4 synchro in the direction assembly of the

transmitter and/or to computers.

Windspeed is determined by the speed of the rotor

assembly. The rotor assembly is held directly into the

wind by the vane assembly. Speed of rotation of the rotor

assembly is proportional to the speed of the wind

striking the blades.

Transmitter

The transmitter consists of two plug-in assemblies,

a direction assembly and a speed assembly. The assem-

blies are housed in a common, dripproof case designed

for bulkhead mounting.

The direction assembly is essentially a servo-

amplifier circuit using a type 18CT4 synchro control

transformer as a receiver for angular displacement sig-

nals representing the position of the vane. The purpose

of the direction assembly is to receive a 400-Hz signal

equivalent to a change in the position of the vane as sent

by the detector and to send this change at a pre-

determined rate, in the form of 60-Hz and 400-Hz

Figure 2-2.--Wind indicator.

synchro signals, to the indicators and/or recorders.

with the exception of their graduated dials, and are

The speed assembly consists of a servo-amplifier

housed in a watertight case, therefore eliminating con-

circuit and a roller disc-type integrator. The servo amp

sideration of the elements when determining location.

lifier uses a type 18CT4 synchro control transformer as

a receiver for signals from the detector representing the

The design of the wind indicating equipment, type

rotating speed of the rotor assembly. The purpose of the

F, allows for the use of a type B indicator with the system

speed assembly is to receive a signal equivalent to a

if so desired. The mounting for both types of indicators

change in rotational speed of the rotor assembly as sent

are basically the same. The selected indicator should be

by the detector, to amplify the signal, and to transmit

mounted on a bulkhead or stationary surface, according

this change at a linear rate, in the form of 60-Hz and

to the applicable dimensions. The location selected will

400-Hz synchro signals, to indicators and/or recorders.

depend upon the intended use of the indicator and the

convenience for wiring and servicing.

The direction assembly and the speed assembly are

basically a servo unit made up of a synchro control

The assemblies mount on individual baseplates. The

transformer, a followup motor, and a synchro

assemblies and baseplates are enclosed in a metal hous-

transmitter.

ing to form a complete wind direction and speed

indicator unit.

The transmitter should be mounted in a location that

is convenient for wiring and servicing. Consideration

The direction synchro receiver receives the angular

for protection from the elements is important, as the case

displacements from the synchro transmitter in the

is dripproof but not waterproof. Ensure the case is

direction assembly of the transmitter unit and indicates

grounded

these displacements on the direction dial. The direction

dial is graduated in 10 intervals from 0 to 360.

Indicator

The speed synchro receiver receives the angular

displacements from the synchro transmitter in the speed

The wind direction and speed indicator (fig. 2-2) is

assembly of the transmitter unit and indicates these

a dual unit consisting of a wind direction assembly and

displacements on the speed dial. The dial is graduated

a windspeed assembly. The two assemblies are the same,

2-3