Station selecting apparatus

摘要

A station selecting apparatus comprises a preset signal generating circuit comprising a charging/discharging circuit including a parallel connection of a variable resistor and a capacitor and being adapted to generate a pulsive preset signal having a pulse width determined as a function of a discharging time constant of the above described charging/discharging circuit. A semifixed resistor is connected between the variable resistor of the preset signal generating circuit and the ground for the purpose of defining the minimum pulse width of the preset signal and a further semifixed resistor is connected in parallel with the variable resistor for the purpose of defining the maximum pulse width of the preset signal.