| 摘要 |
PURPOSE:To shorten the rise time of the crystal oscilltor and to reduce its cost by connecting a heating element to a preheating power source through a switch which can be switched to the power source of the crystal oscillator, and providing a current limiting means which limits a preheating current to the heating element between the switch and the preheating power source. CONSTITUTION:Electric power is applied to a preheating power source terminal 102 and the preheating current is held below a specific value through a current limiting resistance 24. Consequently, when the switch 201 is switched from a side (a) to a side (b), the heating element heats up enough, so the crystal oscillator 51 starts oscillating speedily. Actually, the time when the temperature is stabilized after power-on operation is about 10sec and shortened by preheating. |
