Siren for the model. Scheme, description

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ENCYCLOPEDIA OF RADIO ELECTRONICS AND ELECTRICAL ENGINEERING
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Siren for the model. Encyclopedia of radio electronics and electrical engineering

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Encyclopedia of radio electronics and electrical engineering / Calls and audio simulators

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The English magazine "Practical Viles" published a relatively simple siren circuit for models and toys. The sound generator is made on two semiconductor devices VT1, VT2, connected according to the unijunction transistor circuit. Sound vibrations are amplified by a double emitter follower on transistors VT3, VT4. An ordinary telephone capsule with a resistance of 32-64 ohms was used as a loudspeaker. By manipulating the SA1 switch, the generator mode is changed: when the capacitor C2 is charged and discharged, the siren tone either rises or falls.

Siren for model
Fig. 1

As VT1, you can try to use the transistor KT3107 or KT361, the rest of the transistors can be KT3102, KT315. All semiconductor devices - with any letter indexes.

Literature

Modeller-Constructor №1, 1991, p.44

Publication: cxem.net

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