Figure 9-6.--IC/B3S4 bell.

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Figure 9-6.--IC/B3S4 bell.

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Figure 9-8.--IC/Z1D4 buzzer.

resonating projections to give the sound a distinctive

frequency characteristic. The resonated horn is

designed in a variety of types, differing as to

intensity, frequency, or power supply. Figure 9-9 is

an illustration of a resonated horn.

Motor-operated horns (types IC/H8D3, IC/H8D4,

and IC/H8S3 use electric motors to actuate the

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Figure 9-7.--IC/B2D4 bell.

Horns

There are three types of horns used with the

alarm, safety, and warning systems. They are (1)

non-resonated horns, (2) resonated horns, and (3)

motor-operated horns.

Nonresonated horns (types IC/H1D4, IC/H4D2,

and IC/H4D3) use a diaphragm actuated by a

vibrating armature to produce sound of the required

intensity.

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Resonated horns (types IC/H2S4 and IC/H2D4)

Figure 9-9.--Resonated horn.

also use diaphragms and, in addition, have

9-9