| 摘要 |
PURPOSE:To correct the variance of the oscillation frequency to a temperature change by controlling the generation data of a CPU stored in a pair with the temperature data after applying the generation data to a reference oscillator with D/A conversion. CONSTITUTION:When the data to be stored to a RAM8 is produced within a range of applied temperatures, an antenna 1 is connected to a receiver 2 to receive a known radio wave having an accurate frequency such as a standard radio wave, etc. Then coincidence is obtained between the display frequency of the receiver 2 and a known frequency. While the output 54 of a reference oscillator 5 is given to the receiver 2 as a standard for setting and display of the reception frequency. A voltage control variable capacity diode 53 is connected to a crystal oscillator 52 which decides an oscillation frequency. Then the control voltage 41 to be applied to the diode 53 is varied to perform the fine control of the oscillation frequency. This compensates the variance of the oscillation frequency due to a temperature change and secures a fixed frequency. |
