Telephone circuit with two operational amplifiers serving as differential amplifiers
摘要
Telephone circuit with two operational amplifiers serving as differential amplifiers amplifies voltage applied to earpiece via telephone line for operator's telephone appts.
申请公布号
DE4317181(A1)
申请公布日期
1993.12.02
申请号
DE19934317181
申请日期
1993.05.22
申请人
AKG AKUSTISCHE U. KINO-GERAETE GES.M.B.H., WIEN, AT
