Electro-mechanical vibration exciter with a frequency dependent mechanical vibration system

摘要

899,208. Reciprocating motors and generators. AVERY Ltd., W. & T. Sept. 5, 1960 [Sept. 10, 1959], No. 30481/60. Class 35. [Also in Group XXXVIII] An amplifier 8 feeds a coil 6, which vibrates in the field of a permanent magnet 5 and is connected by a spring 7 to a member 4 gripping a test piece 2. Voltages produced by mechanical vibrations of the coil 6 are fed back to the amplifier 8.