Voltage Regulators 78XX

Voltage regulators are used in the circuits to provide a constant required voltage and to avoid major fluctuations in the voltage to the circuit.

The most common voltage regulators used are
1.7805
2.7809
3.7812

7805 voltage regulator:

It has 3 pins. The input pin,ground pin and the output pin. The input voltage must be within the range of 5V to 30V. So the volage regulator regulates the voltage to 5V.
The connections are shown as;

So the regulated voltage is now used to any electronic circuits,

i.e. Light sensor,dark sensor circuits,etc,.

Voltage Regulator 7905:

The differences in 7905 from 7805 is that the output voltage is negative and the pins are changed.

The picture shows the differences between the 78XX and 79XX regulators

some other voltage regulators ,which has different output voltages are

7812: output voltage is 12V

7809: output voltage is 9V

So that's the basic informations of the most widely used voltage regulators.