| 摘要 |
PURPOSE:To obtain a stable characteristic, by applying a voltage to a diaphragm formed with a synthetic resin having elasticity mixed with carbon particles and changing electric signals flowing to the diaphragm via the change in the resistance value of the diaphragm through the compression and expansion of the diaphragm. CONSTITUTION:Sound waves from a sound source drive a condencer microphone unit 18 arranged in front of a protector 16 to output an audio current to the primary winding T1 of a transformer T. Further, the sound waves from the sound source enter a case 11 through a hole 17 and oscillate an oscillation electrode 12. When the oscillation electrode 12 is oscillated, a conductive elastic body 15 of a coil spring fitting one end to an external electrode 14 is compressed and expanded. Since the conductive elastic substance 15 is formed by mixing carbon particles to silicon rubber, it has a good elasticity and a resistance value between both ends of the conductive elastic substance 15 is changed through the expansion and compression, and a current flowing between the external electrodes 13, 14 is changed according to the sound waves. As a result, the audio current flowing between the external electrodes 13, 14 flows to the primary winding T1 of the transformer T. |
