5V regulated powersupply
this circuit is based on the common and well known 7805 voltage regulator the 7805 can supply requlated +5V supply and 1A current, most digital circuits need +5V regulated supply so this circuit is ideal. the input to this circuit must be atleast +7V to get +5V out, this circuit will not work if you put 5V,6V, to input because these 78XX requires 2V greater voltage than output voltage, for example : you have a 6V powersupply and want to get 5V out of it and you want to use 7805 for this purpose! But you will not make it possible!! Because it needs 7V input to output 5V. u can input upto 30-35V in input pin and you will get regulated +5V output.
The last two digits indicate the output value. As an example 78″05” indicates that it can output max 5V and “7808” can output max 8V And “7812” can output max 12V. And capacitor value depends on the voltage you give to input, You must use 25V capacitor in input if you want to input +12V, and always choose the value(voltage rating) of capacitors greater than input voltage. You can directly replace 7805 with any 78XX Series iCs but input voltage should be greater according to the value of output.