Speed Controller Educates DC Fans

The MC642 PWM fan-speed controller converts any standard two-wire brushless dc fan into an intelligent fan by providing temperature-proportional speed control. With on-board fault-detection circuitry, the device monitors and controls fans of any current or voltage. The required control voltage of 1.25 to 2.65V for 0% to 100% PWM duty cycle is supplied by a thermistor connected to the voltage input. An integrated start-up timer ensures that the fan starts and operates coming out of shutdown mode or following a transient fault. Pricing is $1.34 each/10,000.