US 2008/0165020 A1 · FAN FAILURE ALARM DEVICE

Abstract

A fan failure alarm device includes a first digital-analog converting circuit (200), a first diode (D11), a switching circuit (260), an input-output (I/O) controller (U11), and an alarm circuit (270). The first digital-analog converting circuit receives a digital pulse signal from a first fan, and outputs a direct current (DC) voltage signal at an output terminal. The first diode with a cathode coupled to the output terminal of the first digital-analog converting circuit, the first diode turns on when the first fan stops rotating. The switching circuit with an input terminal coupled to an anode of the first diode, outputs a first control signal when the fan rotates normally and outputs a second control signal when the fan stops rotating. The input-output (I/O) controller receives the first and second control signals from the switching circuit, and outputs an alarm signal when receives the second control signal. The alarm circuit receives the alarm signal from the I/O controller, and activates an alarm.

Claims10

Dependent claims

A fan failure alarm device comprising:

a first digital-analog converting circuit configured for receiving a digital pulse signal from a first fan, and outputting a direct current (DC) voltage signal at an output terminal;
a first diode with a cathode coupled to the output terminal of the first digital-analog converting circuit, the first diode turning on when the first fan stops rotating;
a switching circuit with an input terminal coupled to an anode of the first diode, and outputting a first control signal when the fan rotates normally and outputting a second control signal when the fan stops rotating;
an input-output (I/O) controller with an input terminal receiving the first and second control signals from the switching circuit, and an output terminal outputting an alarm signal when receives the second control signal;
and
an alarm circuit configured for receiving the alarm signal from the I/O controller, and activating an alarm to indicate a failure of the fan.

3 more elements

An alarm device comprising:

a first digital-analog converting circuit configured to electrically couple to a first fan to receive a digital pulse signal from the first fan when the first fan rotates normally, and output a direct current (DC) voltage signal in response to the digital pulse signal at an output terminal;
a first diode with a cathode coupled to the output terminal of the first digital-analog converting circuit, the first diode turning off when the first fan rotates normally and turning on when the first fan stops rotating;
a second digital-analog converting circuit configured to electrically couple to a second fan to receive a digital pulse signal from the second fan when the second fan rotates normally, and output a direct current (DC) voltage signal in response to the digital pulse signal at an output terminal;
a second diode with a cathode coupled to the output terminal of the second digital-analog converting circuit, the second diode turning off when the second fan rotates normally and turning on when the second fan stops rotating;
a switching circuit with an input terminal coupled to anodes of the first and second diodes, and an output terminal outputting a control signal when one or more of the first and second fans stops rotating;
an input-output (I/O) controller coupled to the output terminal of the switching circuit for receiving the control signal and outputting an alarm signal;
and
an alarm circuit configured to receive the alarm signal from the I/O controller, and activate an alarm to indicate a failure of said one or more of the first and second fans.

5 more elements

Dependencies are inferred from the claim text.

Fan failure alarm device

Life of this patent

Fan failure alarm device

Life of this patent

Abstract

Claims10