US 6,054,823 AGranted

Verification of fan operation

AssigneeTelCom Semiconductor, Inc.

InventorsJerry Collings, Chuong Nguyen, Joseph James Judkins, III, Donald E. Alfano, Ali Tasdighi, Quoi V. Huynh, Sang T. Ngo

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Abstract

An apparatus for sensing the rotation of a brushless DC fan includes the fan and a sense/driver circuit and a capacitance. The sense/driver circuit is coupled to the fan to receive a sense input signal including a fluctuating electrical effect caused by fan commutation events. The sense/driver circuit processes the sense input signal to generate a sense output signal indicative of fan operation. The sense/driver circuit includes an integrated circuit. The integrated circuit includes a sense input pin, a ground return pin, a driver circuit, an integrated filter portion, a filter pin and a level detecting circuit. The capacitance is coupled to the filter pin to provide a filter with the integrated filter portion. The driver circuit includes a control terminal, a first current handling terminal coupled to the sense input pin and a second current handling terminal coupled to provide a ground return pat. The integrated filter portion includes a filter input coupled to at least one of the first and second current handling terminals of the driver circuit, and a filter output for providing a filter output signal to the level detecting circuit. The level detecting circuit generates the sense output signal from the filter output signal. The filter derives the filter output signal indicative of the fan commutation events responsive to receiving a signal at the sense input pin.

Claims27

Dependent claims

An apparatus for sensing the rotation of a brushless DC fan motor, the apparatus comprising:

a fan;
a sense/driver circuit coupled to the fan to receive a sense input signal, the sense input signal including a fluctuating electrical effect caused by fan commutation events, the sense/driver circuit processing the sense input signal to generate a sense output signal from the electrical effect, the sense output signal being indicative of fan operation, the sense/driver circuit including an integrated circuit, the integrated circuit including
a sense input pin, the sense input pin being coupled to receive the sense input signal;
a ground return pin, the ground return pin being coupled to a ground reference potential;
a driver circuit, the driver circuit opening and closing a circuit to connect and disconnect power to the fan, the driver circuit including a control terminal and first and second current handling terminals, the first current handling terminal being coupled to the sense input pin, the second current handling terminal being coupled to provide a ground return path via the ground return pin;
an integrated filter portion, the integrated filter portion including a filter input coupled to one of the first and second current handling terminals of the driver circuit, the integrated filter portion including a filter output for providing a filter output signal;
a filter pin coupled to the integrated filter portion;
and
a level detecting circuit, the level detecting circuit having an input coupled to receive the filter output signal, the level detecting circuit generating the sense output signal from the filter output signal;
and
a capacitance, the capacitance coupled to the filter pin, the integrated filter portion and the capacitance comprising a filter, the filter deriving the filter output signal responsive to receiving a signal at the sense input pin, the filter output signal being indicative of the fan commutation events.

8 more elements

An apparatus for sensing the rotation of a brushless DC fan motor, the apparatus comprising:

a sense circuit coupled to receive a sense input signal, the sense input signal including a fluctuating electrical effect caused by fan commutation events, the sense circuit processing the sense input signal to generate a sense output signal from the electric,l effect, the sense output signal being indicative of fan operation, the sense circuit including
an integrated circuit, the integrated circuit including
a sense input pin, the sense input pin being coupled to receive the sense input signal;
an integrated filter portion, the integrated filter portion being coupled to the sense input pin, the integrated filter portion having a filter output for providing a filter output signal;
a filter pin coupled to the integrated filter portion;
and
a level detecting circuit, the level detecting circuit having an input coupled to receive the filter output signal, the level detecting circuit generating the sense output signal from the filter output signal;
wherein
the filter pin of the integrated circuit is for coupling to a discrete capacitor, the integrated filter portion and the capacitance comprising a filter when the capacitor is coupled to the filter pin, the filter deriving the filter output signal responsive to receiving a signal at the sense input pin, the filter output signal being indicative of the fan commutation events.

6 more elements

Dependencies are inferred from the claim text.