A standard cooling fan is essentially a bladed DC motor. By varying the voltage input across the acceptable range for a fan, the speed of the fan will increase (to added voltage) and decrease (to reduced voltage); a faster fan means more air moved and thus a higher heat exchange rate.
Contact them toll-free from a Vodacom cellphone by dialing 111. Contact them toll-free from a Telkom phone by dialing 0800-111-234. Note: Telkom toll-free numbers are generally NOT toll-free when dialed from a MTN/Vodacom cellphone.
We found an interesting page about how to contact SBC customer service. The page was dedicated to SBC Internet service. The phone numbers listed for were AT&T customer service. Wireless Billing and Technical: 1-800-331-0500. AT&T U-Verse Support: 1-800-288-2020.