12v and 5v Dual Power Supply

We power most electronic circuits and devices by using 12 volt or 5 volt Regulated DC supply, Hence we designed basic 12v and 5v Dual Power Supply with easily available components, and this circuit can used as general purpose regulator power supply source.




Here we have used 1 Amps step down transformer you can use up to your specifications and need. This circuit has two LEDs to indicate output power supply for both 12V and 5V.

Circuit Diagram

Components Required

  1. Step down transformer (0-15V) AC – 1
  2. Bridge Rectifier module – 1
  3. Regulator IC L7812 – 1
  4. Regulator IC L7805 – 1
  5. Capacitors 1000µF, 0.1µF, 100µF, 0.1µF – each 1
  6. Resistors 2KΩ, 1KΩ – each 1
  7. LED Yellow, Green 5mm – each 1

Construction & Working

First step in this voltage Regulator circuit is to step down the input AC power supply from 110V, 230V AC to 15V AC for this process we have used 1 Amps step down transformer. Then step downed AC supply is directly applied to the Bridge Rectifier module, here the AC supply is converted into DC supply.

The output DC supply from Bridge Rectifier module will have AC ripples and some voltage fluctuations as appear in input AC supply. DC supply from Bridge rectifier is applied to Filter capacitor C1 here most AC ripples are removed and then IC L7812 Regulated input unregulated DC and gives Regulated 12 V DC at output pin then C2 capacitor performs high frequency ripple filtering. Output 12 V is taken from this point. LED 1 indicates the 12V DC supply presence.

12 Volt DC again filtered by C3 capacitor and then regulated by IC L7805 regulator, at output of 7805 we can obtain 5 Volt Regulated supply. Capacitor C4 performs high frequency ac ripple filtering and LED 2 indicates presence of 5V output. Common Ground (GND) is used for both 12 V and 5 V DC outputs. You can construct this circuit on common pcb or freely available DC power supply PCB.




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