INDEX

NEGATIVE VOLTAGE REGULATORS
Mostly available -ve voltage regulators are of 79xx family. You will use -ve voltage if you use IC741. For IC741 +12v and -12v will be enough, even though in most circuits we use +15v and -15v. You can get more information about 7905 from the following link.
http://www.national.com/ds/LM/LM7905.pdf
http://cache.national.com/ds/LM/LM7905.pdf
7805 gives fixed -5V DC voltage if input voltage is in (-7V,-20V)

The mainly available 79xx IC's are 7905,7912 1.5A output current,short circuit protection,ripple rejection are the other features of 79xx and 78xx IC's