Designer's Corner 4-20-98Designer's Corner 4-20-98

April 20, 1998 Design News

Designer's corner

Useful technology for your idea file

UV/filtration pitcher

Most travelers have heard the advice: Don't drink the water when traveling overseas. But, what can you do when the spirits run out? Buy bottled water or a filter. The challenge arises when deciding which filter or bottled water to choose.

This device processes approximately 16 ounces of water in about 2.5 minutes. Simply turn the unit on and fill the top reservoir with water. While flowing through a silver-activated carbon filter and into the base reservoir, the water charge receives a 187,000 mW-sec/cm² UV dose.

A power converter or an external battery pack (holding eight C-size batteries) provides power to the high-intensity lamp. One battery pack will process about 75 oz/day for two weeks before the batteries need replacing. Testing for Giardia and Cryptosporidium are still in the works.

John Ferlin, Tri-H₂O Co., 100 North Hill Dr., Unit #1, Brisbane, CA 94005; FAX: (415) 468-2756.

Universal linear luge

Designers installing linear motors, usually add position feedback and a bearing structure to guide the coil over the magnets. Lack of a universal-mounting structure, makes application complex.

Most linear motors quickly bolt into the luge? slide for easy installation. High accuracy crossed-roller bearings ensure precise movements over long travel lengths.

Non-contact encoder, mounted close to the motor, reduces frictional drag and hysteresis. Available for both epoxy and iron core motors, the system handles accelerations to 8 g.

Alan Feinstein, Bayside Motion Group, 135 Ricefield Lane, Hauppauge, NY 11788; (516) 484-5482.

Multi-axis force sensor

Crack propagation from stress concentrations in strain-gauge elements, result in poor performance. Advanced screen-printing technology and high tolerance resistance trimming, eliminating laser contact to reduce cracking, and yield a more robust design.

A ceramic-cross strain gauge senses two or three axes of user input. Sensing elements, screen printed on the mounting substrate, interface with IBM Track Point^TM cursor-control code and the new Philips TPM microprocessor.

Z-axis sensing element uses dedicated half-bridge to deliver output proportional to force. Available in PS2 or RS232 output, with unlimited customization options.

Boris Kamentser, Bokam Engineering Inc., 9552 Smoke Tree Ave., Fountain Valley, CA 92708; (714) 513-2204.