InventorsUS Classes417/326, Including means for selectively varying motor speed or rotary motor direction318/471Responsive to thermal conditionsAttorney, Agent or FirmForeign DocumentsInternational Classes F04B 17/00 H02P 7/00 Issued Patent Number:8157536
Abstract textA rotating speed adjustment circuit for a heat dissipation fan includes a first node, a second node, a reception end for receiving a first control signal, a first resistor coupled to a voltage source and the first node, a second resistor coupled to the first node and the second node, a third resistor coupled to the second node and a ground end, a capacitor coupled to the first node and the ground end, a transistor coupled to the reception end, the second node and the ground end, an oscillator for generating an oscillating signal, and a comparator for comparing a signal of the first node and the oscillating signal, so as to output a second control signal to control a rotating speed of the heat dissipation fan. | 
