| 摘要 |
PROBLEM TO BE SOLVED: To eliminate error factors, and to improve time accuracy by providing two sets of crystal oscillators and oscillation circuits for forming a heterodyne system. SOLUTION: An electronic clock is provided with a crystal oscillator 1, an oscillation circuit 2, an additional crystal oscillator 7, an additional oscillation circuit 8, a mixing circuit 6, a filter 9, a frequency-dividing circuit 3, and the like. Frequencies f1 and f2 from the crystal oscillator 1, oscillation circuit 2, additional crystal oscillator 7, and additional oscillation circuit 8 are mixed by the mixing circuit 6. For an output signal from the mixing circuit 6, a frequency obtained by subtracting the frequency f2 from the frequency f1 is obtained by the filter 9. An output signal from the filter 9 is divided by the frequency-dividing circuit 3. The output signal of the dividing circuit 3 is counted by a counting circuit 4 and is displayed by a display circuit 5, and as a result error components are canceled, and accuracy is improved. |
