At present, mechanical transmissions are mostly powered by electric motors. In the absence of power, it is necessary to create a device that relies on potential energy, including springs and gravity. For example, the solar receiver's automatic tracking of the sun mechanism requires a small, lightweight and accurately automatic control device. We use an alarm clock and an unconventional gearbox to make a clock-controlled transmission that controls the operation of the solar cooktop. It is called the “time control device†(referred to as the time controller) and is used on the flat solar cooker. It has passed the municipal technical appraisal and confirmed to be a new mechanical transmission mode.