Appliance Design - January 2008 - (Page 39)

MOTORS size than conventional BLDC alternatives. Despite the simplified three-step drive, this system delivers equivalent performance in most applications. One example is a 1-Watt, cooling-fan motor (4), shown in Fig. 5. As seen on the circuit board, using SingleSense eliminates five components used in the conventional fan’s board. The drive system for this fan, shown in Fig. 6, uses an IC from USM-III, called Pecos. The 3-phase SingleSense type controller doubled the efficiency of the fan, compared to the traditional single-phase controller, without increasing the price. Another example is an evaporator fan motor for a refrigerator. Most motors in such applications have typically been a shaded-pole design to achieve the lowest cost. However, the efficiency of shadedpole is generally accepted as poor. With the growing interest in improving energy efficiency, appliance makers have been gradually moving to 2-phase and 3-phase BLDC technology at 12 VDC. In this particular refrigerator application, the reduced motor diameter dimension permits improved airflow. (See Fig. 7.) The Powder Keg motor has a diameter of 42 mm. The conventional radial motor has a face area of 61 mm x 75 mm, which restricts the airflow. (See Fig. 7A.) By contrast, the Powder Keg® motor does not interfere with airflow. (See Fig. 7B.) When all the aspects are weighed together, it has been shown that a motor system combining Powder Keg, BUD, and SingleSense technologies can deliver a lower cost brushless motor solution than the other available alternatives, while at the same time, capable of delivering equivalent performance in many applications. In addition, a SingleSense integrated control technology and Powder Keg motor system can even be price competitive with brush type DC motor systems in certain applications. The motor system cost savings for a Powder Keg motor with BUD/SingleSense control can be as high as 60 percent when compared to a conventional 3-phase, bipolar-driven, laminated motor. At higher power (greater 100 W power output) the Powder Keg motor can be used with conventional 3-phase bipolar control technology and still result in a system cost reduction. Also, the resulting motor system is typically smaller and lighter. QSI has built Powder Keg motors covering the power output range of 2 W to more than 500 W. The technology is currently being licensed to motor and semiconductor manufacturers and others. < For more information, enter . . . . . . . . . . . . . . . . . . 303 Or email: Brad Marshall at bradusm3@aol .com, or Christian C . Petersen at cpetersen@quadrantsi .com 1 . SingleSense® is a registered trademark name of Petersen Technology Corp . U .S . patent # 6,891,343, 7,026,773 assigned to Petersen Technology Corp . 2 . BUD™ a trademarked name of Petersen Technology Corp . U .S . patent #’s 7,166,948, 7,202,620 assigned Petersen Technology Corp . 3 . Powder Keg® Patent is a registered trademark name of Petersen Technology Corp . U .S . patent #’s 6,617,747, 6,707,224, and others assigned to Petersen Technology Corp . 4 . “Motor Technology Upgrades Cooling Fans,” Marshall, Petersen, Hodohara, Power Electronics Magazine, August 2007 . 5 . SMC material such as Hoganas’ Somaloy™ 700 6 . “Powder Keg Motors with BUD and Single Sense Control in Automotive Applications,” Christian Petersen, 11-12 June 2007, UK Magnetics Seminar, Helsingborg, Sweden . 7 . AKM data sheet . 8 . Cost study by major systems supplier, private communication . 9 . “Novel System Design for Drive, Commutation and Magnetics,” Marshall, Petersen, Power Electronics, Conference Dallas TX October 2007 . Richco’s new break-away bumper features a removable mounting tab that provides for easy installation. Features • Easy pull-through assembly • Break-away mounting tab • Shock absorbing Silicone rubber • Temperature resistant to 482°F (250°C) Benefits • Absorbs shock • Saves space • Anti-skid/anti-marking • Maintains aesthetics on chassis • No adhesives Richco World Headquarters • 8145 River Drive • Morton Grove, IL 60053 For more Information Enter 114 AD09074Rich1.indd 1 www.applianceDESIGN.com www.richco-inc.com 8/7/07 2008 39 January 11:58:41 AM applianceDESIGN http://www.richco-inc.com http://www.richco-inc.com http://www.appliancedesign.com

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Appliance Design - January 2008 Contents Editorial Shipments/Forecasts News Watch Makers of Commercial Refrigeration Equipment Turn to Variable-Speed Motors to Improve Energy Efficiency. New Motor Design and Control Scheme Makes Brushless Motors More Economically Feasible for a Wider Range of Applications. External Gas Molding, a Relatively New Technique, Solves Many of the Challenges Associated with the Injection Molding of Large Plastic Parts. Plastic Housings Offer Many Benefits: EMI Protection Isn't One of Them. But, New Materials and Techniques are Solving that Problem. Choosing the Optimal Strategy for Effective EMI Shielding Depends on Both Mechanical and Electrical Requirements Ethernet-Enabled Microcontroller Makes Networking Schemes Easier and More Cost Effective to Implement The Ever-Changing Array of Microcontroller Memory Options Makes it Imperative to Keep Abreast of What's Available to Determine the Optimal Choice for an Application. A Vast Range of Components and Finished Products will be Exhibited at the Country's Preeminent HVAC/R Show, AHR Expo, which is Scheduled for Jan. 22-24 in New York. Advertiser's Index Association Report: PRBA

Appliance Design - January 2008

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