Fan motor speed detecting device for use between motor and portable computer, has speed output module making speed output terminal to output speed signal to computer in response to speed of fan motor

摘要

The device has input terminals (331, 332) electrically connected to a constant voltage source and a ground potential respectively. A third input terminal (333) receives a pulse width modulation signal from a portable computer (30) to control the speed of a fan motor (31). A speed output module (32) makes a speed output terminal (334) to output a speed signal to the computer in response to the speed of the fan motor. An independent claim is also included for a motor speed control method in a motor speed detecting device between a motor and a portable computer.