"Cooling Fan Manufacturer" We have much to understand, in fact, DC cooling fan has a lot of equipment above the signal line, here we introduce some of the output signal of DC cooling fan.
Fan cooling fan device dimensions are available with FG or RD signal lines. "Cooling Fan Manufacturer" There are two lines, three lines, four lines. Two lines just positive and negative, in addition to the positive and negative than three poles in addition to the signal line and the signal line, there are two: one is FG, that is, the speed signal is a square wave signal, usually the signal frequency quad rupole fan * actual speed 30 = fan, there will be real slow speed argument. Another is the RD signal, its function is to output low fan operation, the fan does not turn the output high, CPU detects this signal can be learned through the fan is running.
Four-wire "Cooling Fan Manufacturer", in addition to a positive sign and FG, typically PWM another line, from the line input of the PWM signal duty cycle to adjust the fan speed, the speed change of the duty cycle is substantially linear generally at the high end did not change significantly. Change curve and cooling fan design of the internal circuit, can achieve different adjustment range.