| 摘要 |
PURPOSE:To attain strong exciting processing by leading out leads to the outside of a case so as to short-circuit a part of a feedback resistor of an oscillating circuit externally from the case. CONSTITUTION:A crystal oscillating circuit consists of a crystal oscillator 1, feedback resistors 2, 3, capacitors 6-9, resistors 10-13, and a chip formed amplifier 14 or the like. The circuit is formed on one board, which is sealed in a sealing case 15. Then, the feedback resistor 3 is short-circuited by short-circuiting externally terminals 4, 5 at the outside of the sealing case. In short-circuiting the resistor 3, the oscillator 1 is excited strongly. In opening both ends of the resistor 3, the resistance of the feedback resistor is formed by a series resistance comprising the resistors 3 and 2 and an exciting level suitable to the application is obtained as a conventional crystal oscillator. |
