TUNING VOLTAGE GENERATING CIRCUIT FOR ELECTRONIC TUNING CIRCUIT

• Main Author: KONDOU MINORU
• Format: Patent
• Language: English
• Published: 22.03.1983
• Subjects: BASIC ELECTRONIC CIRCUITRY; ELECTRICITY; SELECTING RESONANT CIRCUITS; TUNING RESONANT CIRCUITS

PURPOSE:To obtain a tuning voltage with high accuracy, by using a monostable multivibrator and controlling the time constant with a variable capacitor interlocking with a tuning dial. CONSTITUTION:An oscillator 1 generates a rectangular wave of a specified frequency, a monostable multivibrator MMV2 is triggered in response to the leading or trailing of the rectangular wave and a pulse train signal with a pulse width determined with the time constant is outputted. This output is inputted to an integrator 4 via an inverter 3 to detect a DC component of this pulse train signal. This DC component is applied to an operational amplifier OP. A variable capaitor C1 interlocked with a tuning dial is used for the time constant circuit of the MMV2. The capacitor C1 is changed in response to the tuning operation, the time constant of the MMV2 is controlled and the pulse width of the pulse train signal is changed.