Introduction - If you have any usage issues, please Google them yourself
The design of a digital electronic clock can report time on time and has the function of timing.
Clock function: use digital tube to display the accumulated time, 24 hours as the cycle.
Timing function: it can quickly calibrate the functions of "hour", "minute" and "second".
Timing function: it is specifically required to call 5 times of bass (500 Hz) before the whole point, another high tone (about 1000 Hz) at the whole point, 6 resonance calls, and the interval between two calls is 0.5 s. (optional)
Timing accuracy: the timing error shall not exceed 10 s every day.