| 摘要 |
PURPOSE:To execute quickly an image receiving test in the manufacturing process of a tuner by automating a tuning operation in case when an electronic tuner is installed to a television set and inspected. CONSTITUTION:A tuning voltage generating circuit and a supplying and applying circuit are provided in order to apply the tuning voltage to an electronic tuner 2 used for a tuner device of a television 1. The tuning voltage generating circuit is constituted of a control device 3 for generating the preset voltage, a CR discharging circuit 4 and a tuning maintaining circuit 5. An electric power source 7 is charged with the preset voltage corresponding to each channel set by a voltage setting means 6. In case of executing the automatic tuning, charging voltage is discharged through a resistance 9 by depressing a push-button switch 8 corresponding to the channel, charging a capacitor from the corresponding electric power source 7, and subsequently, opening the switch 8. In this discharging process, when AFT signal voltage passes through a singular point of an f-V characteristic curve, a switch 12 is changed over to a contact 16 of the AFT loop side by the control device 3. |
