Abstract: An assembly includes a fan housing that includes a casing and a stator disposed radially inward of the casing and adapted to receive a rotor assembly. Struts attach the stator to the casing. One or more of the struts may define a channel for routing one or more electrical wires. A fan guard helps prevent accidental contacting of the fan blades. The fan guard may be mounted to the struts and may be flush with the housing, and/or may be adapted to cover at least a portion of the channel, thereby trapping the electrical wire(s) in the channel.

Abstract: A control circuit is provided for regulating the rotational speed of a brushless DC motor by pulse width modulating at least one power transistor to pass a motor supply signal to the motor armature. A voltage averaging circuit generates an averaged signal indicative of the average voltage level being supplied to the motor. The averaged voltage signal is compared against a reference voltage to determine motor speed error in order to maintain the rotational speed of the motor at a generally constant level. A sawtooth or other periodic ramp signal is added to a motor current signal, and this composite signal is monitored by a comparator until it overcomes the motor speed error signal. The pwm circuit thereby modulates the power supply to regulate motor speed while maintaining a symmetrical motor armature current waveform.

Abstract: A fan assembly has a fan housing defining mounting apertures, a sheet metal mounting member for mounting the fan housing thereon, mounting tabs extending outwardly of the mounting member and received within the mounting apertures of the fan housing, and threaded fasteners received within the mounting apertures of the fan housing and engaging both the mounting tabs and the fan housing to secure the fan housing to the mounting member. Each mounting tab is formed by piercing the sheet metal mounting member with a forming tool, and moving the forming tool through the pierced mounting member to thereby move the pierced metal in the shape of the tab outwardly of the mounting member. The mounting tabs are received within the mounting apertures of the fan housing, and self-tapping fastener are inserted into the mounting apertures of the fan housing and engage both the fan housing and the mounting tabs to secure the fan housing to the mounting member.

Abstract: A control circuit is provided for regulating the rotational speed of a brushless DC motor by pulse width modulating at least one power transistor to pass a motor supply signal to the motor armature. A voltage averaging circuit generates an averaged signal indicative of the average voltage level being supplied to the motor. The averaged voltage signal is compared against a reference voltage to determine motor speed error in order to maintain the rotational speed of the motor at a generally constant level. A sawtooth or other periodic ramp signal is added to a motor current signal, and this composite signal is monitored by a comparator until it overcomes the motor speed error signal. The pwm circuit thereby modulates the power supply to regulate motor speed while maintaining a symmetrical motor armature current waveform.

Abstract: A control circuit for a pulse width modulation (PWM) driven electric motor is provided for operating a fan or motor at a full duty cycle in the event that the PWM input signal should malfunction or fail. The control circuit includes a pulse width modulation (PWM) source having an output; a switch having a control and being coupled between a voltage source and the motor; a capacitor having an input coupled to the PWM output and an output coupled to the switch control, and a diode coupled between the PWM output and the switch control for maintaining the output of the capacitor at a predetermined minimum voltage level. In response to a substantially direct voltage level at the PWM output indicative of a failure of the PWM source, the capacitor maintains at its output a voltage level sufficient to cause the switch control to connect the voltage source to an input of the electric motor and drive the electric motor at a full duty-cycle. The diode provides d.c.

Abstract: A blank formed from electrically conductive sheet material defines a continuous conductive path which includes two terminal ends and at least three loops disposed along the path. The blank is foldable at preselected folding locations on the path to position the loops in overlying relation to one another, and the blank is preferably formed with the loops disposed along the conductive path in substantially the same plane. The blank is used to form a multi-turn planar winding for a magnetic device such as, for example, an inductor or transformer which may be incorporated into electrical circuits such as power supplies. The planar magnetic device provides a low overall volume and profile, as well as a substantially higher volume or surface area of conductive material per turn of the winding compared to conventional wire or etched windings to provide a higher current carrying capacity and fewer turns compared to conventional windings.

Abstract: A blank formed from electrically conductive sheet material defines a continuous conductive path which includes two terminal ends and at least three loops disposed along the path. The blank is foldable at preselected folding locations on the path to position the loops in overlying relation to one another, and the blank is preferably formed with the loops disposed along the conductive path in substantially the same plane. The blank is used to form a multi-turn planar winding for a magnetic device such as, for example, an inductor or transformer which may be incorporated into electrical circuits such as power supplies. The planar magnetic device provides a low overall volume and profile, as well as a substantially higher volume or surface area of conductive material per turn of the winding compared to conventional wire or etched windings to provide a higher current carrying capacity and fewer turns compared to conventional windings.

Abstract: A control circuit for regulating the rotational speed of a DC brushless motor includes an electrical conduction switch having an input, an output and a control terminal for passing a motor supply signal to a DC brushless motor. A voltage averaging circuit generates an averaged signal indicative of the average voltage level being supplied to the motor. The averaging circuit informs an error amplifier to modulate the motor supply signal to compensate for changes in the voltage level of the motor supply signal in order to maintain the rotational speed of the motor at a generally constant rpm. The control circuit takes advantage of the motor windings and rotor mass as a filter circuit to smooth changes in current drawn by the motor, and to further maintain the rotational speed of the motor.

Abstract: The invention provides a motor and a bearing support and motor housing assembly, wherein the bearing support is detachably mounted to the housing with a flexible fastener, such as a snap ring. A resilient member, such as a spring washer, is seated between the fastener and either the housing or the bearing support to apply a biasing force against the fastener.

Abstract: In a low-profile printed circuit device, a first substrate is provided with a planar magnetic transformer and a planar magnetic inductor. The transformer and the inductor each have a primary winding defining spiral conductive patterns disposed on opposite sides of the first substrate relative to each other, and an inductive core extending through a respective inner aperture formed through the first substrate and surrounded by the respective primary winding. A second substrate is also provided, having a secondary transformer winding and a secondary inductor winding. Each secondary winding defines respective spiral conductive patterns disposed on opposite sides of the second substrate, and surrounding respective inner apertures extending through the second substrate.