US Patent 10495096 Heat dissipation system and fan driving circuit

A heat dissipation system includes a control module, a first fan module and a second fan module. The first fan module is electrically connected to the control module to provide a speed signal to the control module. The second fan module is electrically connected to the control module and the first fan module. The control module provides at least one control signal to control the rotation of the first fan module and the second fan module respectively. The first fan module transmits a first trigger signal to the second fan module, and the second fan module starts to rotate or stops rotating together with the first fan module according to the first trigger signal.