One practical and cheaper approach to reduce ripple voltage is to use an off the shelf
3
-
terminal IC voltage regulator, such as a
LM78xx
(where "xx" stands for the output voltage
rating) for a positive output voltage or its inverse equivalent the
LM79xx
fo
r a negative
output voltage which can reduce the ripple by more than 70dB (see datasheet) while
delivering a constant output current of over 1 A.
Figure
4
depicts picture, pin diagram, and a
typical circuit of a
12V 3
-
terminal IC voltage regulator
in TO220
case style
.