Abstract
We put global radio time signal "Cal.U600" on the market in June, 2007. The performance of the high sensitivity that can be the electric wave reception in the North America continent is installed in this watch. "Cal.U600" is achieved operativeness and the visibility by installing of the combinations display, the winding stem and the pushbuttons. This wristwatch has the function that is called "Impact detection function". This function puts the electromagnetic brake on the motor when the impact is detected. As a result, it has the display means of high reliability to the impact in this wristwatch. Moreover, the sensor is not needed because the impact has been detected with the stepping motor.
