A voltage regulator is used to produce a constant linear output
voltage. It’s generally used with AC to DC power supply. And also it can
be used as well as a DC to DC voltage converter
. To regulating low voltage, most used device is one single IC. 7805,
7812, 7905 etc. 78xx series are design for positive and 79xx series are
for Negative voltage regulator.
7805 is a three terminal +5v voltage regulator IC from 78XX chips family. See 7805 pinout
below. LM78XX series are from National Semiconductor. They are linear
positive voltage regulator IC; used to produce a fixed linear stable
output voltage. National Semiconductor has also negative voltage
regulator chips family, they indicate with LM 79XX. 78xx is used more
than 79xx because negative voltage has a few usability purposes as we
see.
I was previously posted a 5v regulated power supply circuit using 7805 IC, that circuit and this 7805 voltage regulator circuit is almost the same.
I was previously posted a 5v regulated power supply circuit using 7805 IC, that circuit and this 7805 voltage regulator circuit is almost the same.
Its output voltage is +5V DC that we need. You can supply any voltage in
input; the output voltage will be always regulated +5V. But my
recommendation is, don’t supply more than 18V or less than 8V in input.
There used two capacitors in this voltage regulator circuit, they aren’t
mandatory to use. But it will be best if you use them. They helped to
produce a smooth regulated voltage at output. Use electrolyte capacitor
instead of ceramic capacitor.
One limitation of 7805 I have found that is its output current 1A maximum. Otherwise it is a good voltage regulator if you are happy with 1A. But if you need over 400mA current in output then you should use a Heat Sink with IC LM7805. Otherwise it may fall damage for overheating.Link
