AUDIO FREQUENCY ANALYSIS USING MICROCOMPUTER

摘要

An adder (2) and a frequency selector (3) to which a voltage controlling wave generator circuit (4) connected to OP amp (OP2) is connected are connected to a first and a second ports of an interface circuit (1). A third port of the interface circuit is connected to output terminal (out) of an A/D converter (5). A filter circuit (6) including OP amps (OP3-6) is connected to an A/D converter input terminal. The amplifier to be measured is connected between the Op amp (OP2) output terminal and the filter circuit.