| 摘要 |
PURPOSE: To provide a luminescent clock attaining a proper visual effect. CONSTITUTION: An EL element 1 shows the luminescent color corresponding to the frequency of the drive AC voltage generated by a driving circuit 2. The driving circuit 2 is constituted of an astable multivibrator 3 generating the oscillation output corresponding to a connected resistance value and a transformer L fed with electrical power from a transistor to driven by the oscillation output. The frequency of the driving AC voltage generated by the secondary coil 12 of the transformer L coincides with the frequency of the oscillation output of the astable multivibrator 3. The resistance value is periodically switched by a resistance changing circuit 4 to change the oscillation frequency, and the luminescent color is also switched. The dazzling and bothering impression caused when the brightness of the EL element 1 is excessively switched is not given to a user. The switching cycle is accelerated by a selecting circuit 7 as the present time counted by a time control circuit 8 approaches the alarm time, and a sufficient visual effect is obtained.
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