摘要 |
PURPOSE:To actuate normal oscillation in a short time by operating an oscillation frequency control part after operating an oscillation part. CONSTITUTION:The oscillation frequency control part 19 is variable capacitance equivalently and a DC signal impressed to the base of a transistor (TR) 23 is varied to vary the oscillation frequency of the oscillation part 10. When an oscillation stop switch 29 is turned on, the base of a TR13 is grounded and the oscillation part 10 stops oscillating. At the same time, the base of the TR23 is also grounded and the control part 19 also stops oscillating. When a switch 29 is turned off for restarting the oscillation, the discharging of a capacitor 31 starts. Then, a TR39 turns off after a TR36 turns off. Therefore, the oscillation part 10 starts free-run oscillation immediately, and then control part 19 starts operating, so no unnecessary current flows through an oscillator 18, speeding up the start. |