Patents
Patents for H04R 13 - Transducers having an acoustic diaphragm of magnetisable material directly co-acting with electromagnet (404)
05/1978
05/16/1978US4090041 Electromagnetic sonic generator for an alarm
02/1978
02/21/1978US4075437 Chromium, cobalt, iron, zirconium, aluminum niobium, and/or titanium
04/1977
04/05/1977US4016376 Concave diaphragm for electro-acoustic transducer
03/1977
03/29/1977US4015227 Electromagnetic transducer
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