Patent ID: 8299735

Claim:
A fan system, comprising: a motor with a coil module having a first connection terminal and a second connection terminal; a storage unit electrically coupling with a voltage source, storing electrical energy when the voltage source is available, and releasing the stored electrical energy to carry out a brake operation when the voltage source is unavailable; a driver electrically coupling with the first and second connection terminals of the coil module to control a direction of an inductor current passing through the coil module, wherein the driver is a full bridge driver having an upper switch module and a lower switch module, with each of the upper and lower switch modules being constructed by two electronic power switches; a buffer circuit electrically coupling with the coil module; a control unit electrically coupling with the driver; and a brake circuit electrically coupling with the control unit, with the brake circuit having two electronic power switches, with each of the two electronic power switches of the brake circuit having an output terminal, and with the two output terminals respectively coupling with the electronic power switches of the lower switch module through input terminals thereof, wherein, in the brake operation, the buffer circuit operates to form a transient potential between the first and second connection terminals of the coil module and to consume electrical energy of the inductor current, for gradually stopping the motor in a buffering time period.