公开(公告)号：US3664744A

公开(公告)日：1972-05-23

申请号：US3664744D

申请日：1969-09-02

Applicant: SMITH KLINE INSTR

Inventor： LISTON MAX D

IPC: G01J1/16 ,  G01N35/00 ,  G01N35/04 ,  H03M1/00 ,  G01J3/42 ,  G01J1/10 ,  G01N21/20

CPC classification number: G01J1/16 ,  H03M1/58

Abstract: A RATIO METR FOR GIVING THE LOG OF THE RATIO OF TWO VOLTAGES. AN RC CIRCUIT IS CHARGED AND ALLOWED TO EXPONENTIALLY DISCHARGE. COMPARATOR MEANS RECEIVE THE TWO VOLTAGES AND THE VOLTAGE OF THE RC CIRCUIT AND PROVIDE OUT PUT SIGNALS WHEN EACH OF THE TWO VOLTAGES IS EQUAL TO THE VOLTAGE OF THE RC CIRCUIT. THE TIME LAPSE BETWEEN SAID TWO SIGNALS CORRESPONDS TO THE LOG OF THE RATIO OF THE TWO VOLTAGES.