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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 .
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The LM78XX series typically has the ability to drive current up to 1A. For application requirements up to 150mA, 78LXX can be used. LM7805 has three legs: Input leg which can hold up to 36VDC Common leg (GND) and an output leg with the regulator's voltage. For maximum voltage regulation, adding a capacitor in parallel between the common leg and the output is usually recommended. Typically a 10uF & 100nF capacitor is used. This eliminates any high frequency AC voltage that could otherwise combine with the output voltage. See below circuit diagram which represents a typical use of a voltage regulator.
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 three 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.
Part list
LM7805
1000uF
10uF
100nF
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