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.
1 Pay monthly and business customers â 191 free from a Vodafone mobile or +44 7836 191 191 from any other phone (international call charges apply). 2  Pay as you go customers â 191 from a Vodafone mobile (calls cost 25p) or +44 7836 191 919 from any other phone (international call charges apply).