ACCELERATION TYPE MICROPHONE FOR PHONOCARDIOGRAPH

摘要

PURPOSE:To decrease remarkably defective microphone for phonocardiograph by allowing a magnetic force by means of a magnet having a large magnetic energy product to couple ceramic beam and weight and a support base so as to protect the ceramic by means of the attaching and detaching operation of the magnet against a shock more than required value. CONSTITUTION:Electrode faces at both ends in the lengthwise direction of a paper-tablet form ceramic beam 1 are bonded by a ceramic support iron piece 2 with an adhesives or the like and the bonded parts are inserted to the inside of a cylindrical aluminum enclosure 3. The said ceramic beam 1 is attracted and supported by an attracting force of a ceramic support magnet 5 fixed to an aluminum-made ceramic fixed base 4 in matching with the support iron piece 2. The center of the ceramic beam 1 is bonded to the weight 7 by a weight/ceramic bonding column 6 through a hold at the center of the ceramic fixed base 4. The said weight/ceramic bonding column 6 is a phosphorous bronz spring rod, its one end is bonded to a copper-made frame clipping the ceramic nearly in the U-form and the other end is bonded to an iron post 9 attracted mutually with a weight attaching/detaching magnet 8 fitted to the center of the weight 7.