Electrical transmission or interconnection systems – Personnel safety or limit control features – Interlock
Patent
1985-10-21
1986-12-16
Miller, Stanley D.
Electrical transmission or interconnection systems
Personnel safety or limit control features
Interlock
307540, 307572, 307564, H03K 333, H03K 508, H03K 17687
Patent
active
046299106
ABSTRACT:
An integrated circuit amplifier for a high impedance microphone (100) of the capacitance type is disclosed. The subject amplifier circuit permits the further miniaturization of an electret microphone as it is capable of providing an input impedance simulating a resistor value of hundreds of megohms. The circuit particularly comprises duplicate coupling circuits (101a and 101b), a source of reference direct current voltage (103), and a gain providing circuit (102). The coupling circuits (101a and 101b) comprise a first pair of diodes (Q1 and Q2) symmetrically placed about one input terminal (IN1) of the microphone (100). Outputs of the reference voltage source (103) are provided to coupling circuits (101a and 101b) and through the coupling circuits to gain providing circuit 102. Such an arrangement facilitates power supply noise rejection and automatic canceling of direct current voltage drifts.
REFERENCES:
patent: Re27804 (1973-10-01), Treadway
patent: 3262065 (1966-07-01), Fredrickson
patent: 3365546 (1968-01-01), Kemper
patent: 3458828 (1969-07-01), Salman
patent: 3541350 (1970-11-01), Luetze
patent: 3846696 (1974-11-01), Ahmed
patent: 4029974 (1977-06-01), Brokaw
patent: 4166564 (1979-09-01), Ahmed
patent: 4251742 (1981-02-01), Beelitz
Early Scott H.
Minear Roger L.
AT&T Bell Laboratories
Davis B. P.
Miller Stanley D.
Newman Harry L.
Williamson Samuel R.
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