Electronically programmable universal brushless DC fan with integral tracking and locked rotor protection
First Claim
1. In a brushless DC motor driven, equipment cooling fan having a permanent magnet rotor in an impeller, a centrally mounted stator wound with windings, ends of the windings being electrically connected to a winding supply circuit centrally mounted with the stator, a commutation and switching circuit centrally mounted with the stator and the energization circuit, the impeller having blades supported thereon radially outward of the stator;
- the improvement comprising a voltage regulator having thermal protection mounted internally in the winding supply circuit and connected in current conducting relation to the windings, means connected between the voltage regulator and the windings to provide, in cooperation with the voltage regulator, current limiting of the current to the windings, voltage setting means connected to the voltage regulator to set the output voltage thereof and establish a desired fan speed, the commutation and switching circuit having input connection means for supplying current thereto independently of the voltage regulator connected in current conducting relation to the windings.
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Accused Products
Abstract
A brushless DC fan with a winding supply circuit having an internal voltage regulator can afford current limiting and thermal protection and provide various desired fan speeds without alteration of the basic fan circuit, the windings, or other manufacturing items. A voltage setting circuit element can set fan speed externally and can be used to establish various fan speeds. An internal voltage establishing circuit element sets the maximum speed. The regulator replaces the fan'"'"'s protective thermistor to shut down the voltage to the windings when locked rotor occurs. Bringing out a lead for the purpose of connecting a speed controlling resistor, thermistor, or active programming means to the internal circuitry enables the fan'"'"'s end user to alter operation as needed.
105 Citations
16 Claims
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1. In a brushless DC motor driven, equipment cooling fan having a permanent magnet rotor in an impeller, a centrally mounted stator wound with windings, ends of the windings being electrically connected to a winding supply circuit centrally mounted with the stator, a commutation and switching circuit centrally mounted with the stator and the energization circuit, the impeller having blades supported thereon radially outward of the stator;
- the improvement comprising a voltage regulator having thermal protection mounted internally in the winding supply circuit and connected in current conducting relation to the windings, means connected between the voltage regulator and the windings to provide, in cooperation with the voltage regulator, current limiting of the current to the windings, voltage setting means connected to the voltage regulator to set the output voltage thereof and establish a desired fan speed, the commutation and switching circuit having input connection means for supplying current thereto independently of the voltage regulator connected in current conducting relation to the windings.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
- 10. A brushless DC motor driven fan including a permanent magnet rotor in an impeller, a stator wound with windings to form at least one coil, fan housing means, fan circuitry housed in the fan housing means including a winding supply circuit and a commutation and switching circuit, the commutation and switching circuit including switching means for directing DC current to windings of the stator and commutation controlling means responsive to the position of the rotor to control the timing of energization of the windings of the stator, the winding supply circuit housed in the fan further including a voltage regulator integrated circuit having an output connection coupled in current conducting relation to the windings of the stator for conducting current thereto under control of the energization circuit, the voltage regulator integrated circuit having an output voltage controlling circuit element connection external of the housing of the fan for establishing the output voltage provided across the windings by the internal voltage regulator integrated circuit, whereby the voltage regulator and a selected circuit element connected externally of the fan to said circuit element connection set the fan speed.
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16. A method of programming fan speed in a brushless DC motor driven fan including the steps of:
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(a) providing a brushless DC fan having a stator wound with windings, ends of the windings being electrically connected to a winding supply circuit mounted internally of the fan, a commutation and switching circuit mounted internally of the fan and including an internal voltage regulator connected in current conducting relation to the windings; (b) connecting a conductor to an output voltage controlling connection point of the voltage regulator; (c) directing the conductor to a location external of the fan; and (d) controlling fan speed by connecting an external circuit element to the conductor in output voltage controlling relation to the voltage regulator.
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Specification