公开(公告)号：US06528987B1

公开(公告)日：2003-03-04

申请号：US09595953

申请日：2000-06-19

申请人： John Blake ,  David Hanrahan ,  Kohji Yoshida

发明人： John Blake ,  David Hanrahan ,  Kohji Yoshida

IPC分类号： G01P3489

CPC分类号： H05K7/20209 ,  G01P3/489 ,  G06F1/206

摘要： An operating circuit (1) for controlling the speed of a cooling fan motor (3) for computer cabinetry (7), and for determining an under-speed condition in the fan motor (3) comprises a control circuit (15) which controls a variable output signal generator circuit (18) for outputting a pulse width modulated signal corresponding to the desired fan speed for switching a switching circuit (8) in a power supply circuit of the fan motor (3) for pulse width modulating the power supply to the fan motor (3). A monitoring resistor (R1), a capacitor (C1) and a circuit (12) provides a tachometer signal to the operating circuit (1). A gate circuit (22) gates the second and fourth pulses of the tachometer signal to a counter (20) which counts clock pulses from a clock signal generating circuit (19) between the rising edges of the second and fourth pulses which are in turn stored in a register (23) for comparison with a reference count by a comparator (25). The comparator (25) outputs an alert signal in the event of the count in the register (23) exceeding the reference count indicating under-speed of the fan. The control circuit (15) controls the signal generator circuit (18) for holding the pulse width modulated signal outputted to the switching circuit (8) on during a duty cycle between the rising edges of the second and fourth pulses of the tachometer signal so that the tachometer signal remains available until the fan speed has been determined.

摘要翻译： 一种用于控制计算机橱柜（7）的冷却风扇马达（3）的速度并用于确定风扇马达（3）中的低速状况的操作电路（1），包括控制电路（15） 可变输出信号发生器电路（18），用于输出对应于期望的风扇速度的脉宽调制信号，用于切换风扇电动机（3）的电源电路中的开关电路（8），用于将电源的脉冲宽度调制到 风扇电机（3）。 监视电阻器（R1），电容器（C1）和电路（12）向操作电路（1）提供转速计信号。 门电路（22）将转速计信号的第二和第四脉冲门控到计数器（20），该计数器（20）在时钟信号产生电路（19）的时钟脉冲之间计数第二和第四脉冲的上升沿之间， 在用于与比较器（25）的参考计数进行比较的寄存器（23）中。 比较器（25）在寄存器（23）中的计数超过表示风扇低速的参考计数的情况下输出报警信号。 控制电路（15）控制信号发生器电路（18），用于在转速计信号的第二和第四脉冲的上升沿之间的占空比期间保持输出到开关电路（8）的脉冲宽度调制信号，使得 转速计信号保持可用，直到确定风扇速度。

公开(公告)号：US06727689B1

公开(公告)日：2004-04-27

申请号：US10631850

申请日：2003-07-24

申请人： Greg R. Furlong ,  Joel D. Stolfus ,  Jason M. Chilcote ,  Scott L. Bunyer

发明人： Greg R. Furlong ,  Joel D. Stolfus ,  Jason M. Chilcote ,  Scott L. Bunyer

IPC分类号： G01P3489

CPC分类号： G01D5/2448 ,  G01P3/4802 ,  G01P3/488 ,  G01P3/489

摘要： An apparatus and method for detecting gear features is provided. The apparatus includes a magnetic-sensing element, a thresholding module, and an output module. The magnetic-sensing element may provide a sensor-output signal indicative of the presence of a gear feature. The thresholding module may (i) transform the sensor-output signal into a characteristic waveform, which is also indicative of the presence of the gear feature; (ii) detect a first difference between the characteristic waveform and a reference signal, and responsively provide a tracking signal that tracks this difference; and (iii) detect a second difference between the tracking and reference signals, and responsively adjust the sensor-output signal. Adjustment may be performed (i) as a function of the second difference when it falls below a given threshold and (ii) by a predetermined amount when the second difference satisfies the given threshold. The output module may produce an output signal as a function of the characteristic waveform and the reference signals.

摘要翻译： 提供一种用于检测齿轮特征的装置和方法。 该装置包括磁感元件，阈值模块和输出模块。 磁传感元件可以提供指示齿轮特征存在的传感器输出信号。阈值模块可以（i）将传感器输出信号转换成特征波形，其也指示齿轮特征的存在 ; （ii）检测特征波形和参考信号之间的第一差异，并且响应地提供跟踪该差异的跟踪信号; 并且（iii）检测跟踪信号和参考信号之间的第二差异，并且响应地调整传感器输出信号。调整可以在（i）当其低于给定阈值时作为第二差异的函数执行（ii） 当第二差异满足给定阈值时的预定量。 输出模块可以产生作为特征波形和参考信号的函数的输出信号。

公开(公告)号：US06262549B1

公开(公告)日：2001-07-17

申请号：US09607024

申请日：2000-06-29

申请人： Ta-yung Yang ,  Jenn-yu G. Lin ,  Cheng-chi Hsueh

发明人： Ta-yung Yang ,  Jenn-yu G. Lin ,  Cheng-chi Hsueh

IPC分类号： G01P3489

CPC分类号： G01P3/489 ,  G01P3/481 ,  Y10S388/912

摘要： A fan speed pulse filter is used for a PWM fan. The filter comprises a comparator, a latch circuit and a synchronizer. The fan unit, including a tachometer pulse output, is controlled by a PWM signal for determining the fan speed. By comparing the PWM signal with a reference voltage, the comparator generates a reset signal. The latch circuit, coupled to the comparator and the fan unit, receives the reset signal and the tachometer pulse and outputs a filtered tachometer pulse containing no phantom pulses. Furthermore, a synchronizer generates an output signal without interruption when the PWM signal is switched off.

摘要翻译： 风扇转速脉冲滤波器用于PWM风扇。 滤波器包括比较器，锁存电路和同步器。 包括转速计脉冲输出的风扇单元由用于确定风扇速度的PWM信号控制。 通过将PWM信号与参考电压进行比较，比较器产生复位信号。 耦合到比较器和风扇单元的锁存电路接收复位信号和转速计脉冲，并输出不含幻影脉冲的滤波转速计脉冲。 此外，当PWM信号关闭时，同步器产生输出信号而不中断。