"Micro Cooling Fan" driving DC power supply is necessary! Voltage DC power supply used must be marked on the fan operating voltage of the same. Battery is a DC power supply, if using it to drive the DC fans, in addition to the charge depends on the battery voltage outside the operating voltage of the fan are the same. If not necessary to use DC / DC converter of the voltage becomes the same. "Micro Cooling Fan" tachometer signal is generally output from the three-wire plug, three leads, yellow and black, respectively + 12V power and ground, another color of the line is the line speed signal output. It should be noted that some three-lead of a third wire DC fans are not speed signal output line, but the speed control signal line speed control signal input through which the "Micro Cooling Fan" motor.