Advanced laboratory practice in electricity and magnetism (1922)
Terry, Earle Melvin, 1879-1929 · New York, McGraw-Hill · leaf 169
rdinary way by a tele-phone transformer. Any stray soundwill cause a variation in the microphonecurrent which produces a sound in thereceiver. This sound is fed back tothe microphone which again produces asound in the receiver and the action isthus continuous, the energy being supplied by the… … Fig. 86.—Microphonehummer. DETECTING DEVICES 155 secondary or receiver circuit. If the resistance of this circuit isnot too large, it may be made oscillatory by the introduction of acondenser as indicated in the diagram. By giving suitable valuesto the capacitance of this condenser a large range of…
Electricity · Magnetism
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