×

Signal summing non-microphonic differential microphone

  • US 5,335,282 A
  • Filed: 07/22/1992
  • Issued: 08/02/1994
  • Est. Priority Date: 07/22/1992
  • Status: Expired due to Term
First Claim
Patent Images

1. A microphone for converting sound pressure variations to electrical signals having a positive phase when acted upon by a force in a first direction and a negative phase when acted upon by a force in the opposite direction, said microphone comprising:

  • at least a first pressure transducer acoustically coupled to the environment and having an electrical output of a first phase,at least a second pressure transducer oriented oppositely to said first pressure transducer and acoustically coupled to said first pressure transducer to produce an electrical output of the same phase as said first pressure transducer, andcircuit means combining the electrical output of said first pressure transducer and the electrical output of the said second pressure transducer,said circuit means comprising a number of field-effect or bipolar transistors having their respective gates connected to their respective transducer outputs of the same number as the transistor, the sources and drains of said transistors being so connected that the amplified signal outputs of the transducers are superimposed in series,whereby an acoustic signal directed to both the first and second transducers produces output phases that are additive, and a randomly directed pressure impulse produces both positive and negative output phases which electrically cancel the oppositely oriented transducers, and the outputs of the transducers are combined to increase the output level of the microphone in relation to the number of transducers.

View all claims
  • 0 Assignments
Timeline View
Assignment View
    ×
    ×