| 摘要 |
PURPOSE:To obtain stable operation output without being influenced by drift by providing a tracking circuit that receives tracking signal and output of a polarity inverting circuit, inputs the output to an analog integration circuit and constitutes a closed loop. CONSTITUTION:A digital processing section 1a receives signals from a process input, operation output and coefficient setting circuit and makes PID operation in digital and outputs integrated value converted to analog value, proportional term and differential term. It is provided with an analog adder circuit 9 that receives integration output and proportional term and differential output from a processing section 1a at the time of automatic setting A, and adding them and takes out operation output. A manual operating circuit 7 outputs manual operation voltage responding to operation of a manual operation M, and gives output of the circuit 7 to the circuit 9 through an analog integration holding circuit 4a. A polarity inverting circuit 10 is connected to output terminal of the circuit 4a and a tracking circuit B that receives output of the circuit 10 and tracking signal, inputs the output to the circuit 4a and forms a closed circuit. |
