| 摘要 |
PURPOSE:To make the usage of a clock easy, by generating an alarm sound at a correct minute of a normal time, even if the set of the alarm time is shifted from the correct minute, through the generation of alarm sound with the detection of the position of pointer within one minute. CONSTITUTION:To a counter of a main count circuit 10, a difference between an alarm set time and a normal time is stored. This difference is counted up or down with a signal in 1/20Hz or the like, AND gates 16, 18 and 19 are controlled, and when the normal time is within 20sec of the alarm set time, an FF17 is set and an AND gate 20 is closed. On the other hand, a pointer position detecting circuit 7 detecting the position of pointer within one minute counts the 1/20Hz signal and when the count value reaches 3, a correct minute output is generated via a counter to be reset. This output controls the generation of alarm sound via the gate 20. Thus, even if the setting of the alarm time is shifted by 20sec or the like from the correct minute, the alarm sound is generated at the correct minute of the normal time. Then, a pointer type alarm clock with ease of use can be obtained without mis-judgement as out of order due to to the shift in the set time. |
