| 摘要 |
<p>A VOLTAGE CONTROLLED OSCILLATOR CIRCUIT This disclosure relates to a transistorized voltage controlled oscillator circuit for an automatic train operating system. The voltage controlled oscillator circuit includes an operational amplifier having a first and a second input terminal and an output terminal. A first resistor is connected between the first input terminal and a reference potential, and a current limiting resistor is connected between the second input terminal and an input signal voltage. A charging capacitor is connected between one end of the first resistor and the second input terminal. A series connected diode and capacitor are connected between the other end of the first resistor and the reference potential, and a feedback resistor is connected between the output terminal and the second input terminal. A solid state output amplifier has an input and an output circuit. The output terminal of the operational amplifier is coupled to the input circuit of the solid state amplifier, and the output circuit of the solid state amplifier is resistively coupled to the junction of the series connected diode and capacitor. A series connected diode and resistor are connected between the output circuit of the solid state amplifier and the charging capacitor whereby a dead band zone occurs until the input signal voltage on the second input terminal reaches a predetermined value for toggling the operational amplifier and for producing output signals having a frequency proportional to the amplitude of the input signal voltage.</p> |
