12V & 5V Dual power supply Circuit

12v-5v-dc-circuit-dual-power-supply-circuit
Dual power Supply Circuit

Power supply form the basic building block of any electronic circuits and therefore its important to familiarize the DC power supply circuit construction. The above given circuit illustrates a simple approach to construct a dual DC power supply of 5V and 12V from the 230V AC mains supply. The Voltage ranges 5V and 12V are widely used in all kinds of simple electronic circuits, so its meaningful to learn this simple construction. 

WORKING OF DUAL POWER SUPPLY CIRCUIT:

The above circuit obtains power from a 230V AC mains supply voltage and fed into a step down  transformer for transforming higher voltage supply to lower one. The transformer TR1 can be of 230V primary ,15V secondary and 1A step down transformer. The stepped down voltage can be fed into the bridge rectifier made of four 1N4004 diodes for the conversion of AC supply to DC one. 

78xx-pin-pinout-diagram
IC regulator pinout

The output from the bridge rectifier was filtered by the capacitor C1 and C2 to offer a steady DC level to the input pins of the regulators used in the above circuit. The DC voltage is then fed in to the IC 7805 which is a 5V regulator and also to the IC 7812 which was a 12V regulator. The output obtained from the 7805 & 7012 are 5V and 12V respectively. A LED D5 was connected through the current limiting resistor R1 for indicate the state of the device.

This kind of circuits are highly useful where two dual range of DC voltages are used to power the operation of a circuit. Varying the voltage regulator IC ‘s 7805 or 7812 with 7806 and 7808 to obtain 6V and 8V as output. But each IC have minimum and maximum voltage requirements, so make sure you build in such a way to meet the requirements. 

PCB LAYOUT EXCLUDING TRANSFORMER:

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Frank Donald

Frank Donald

Junior Network Engineer at Tata Communications
Frank Donald is an Electronics and Communication Engineer who loves building stuff in his free time. Video games, blogging and programming are the things he loves most

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43 Comments on "12V & 5V Dual power supply Circuit"

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Akash
Guest

i made this circuit but, the problem is when i connect the load to the 5v output supply i get only 6V from the 12V outpit pin.

Kartik Sikka
Guest

Hi Frank
You have done an awesome work by providing us the schematic with PCB Design . Thank for that !!

There is one thing , I want to ask that can i add 7809 in b/w 7812 & 7809 , as i want to make Power Supply which could deliver all three outputs 12V,9V,5V

Sommy
Guest

Please can I use a 230-12v 500mA transformer instead

yie
Guest

i’am ask to my supervisor our project,he say the circuit is false,can u explain to me sir??

Reyna
Guest

Will it be okay if i used LM317 instead of IC 7812?

Ammara
Guest

can this supply feed 2A load?

Stephanie
Guest

I have an 18V 2A transformer. will it be ok?

ponynamas
Guest

hello, i want to connect a dc motor of 12V,300mA as the load and i have 1A transformer, how can I control the current from 1A to 300mA?

kamal arunashanthi
Guest

Hi there I have made this regulator .But I can have very descant 5 v supply but I cant get 12 v with at least 200 ma what is the problem Please advice me.

Clariza
Guest

Hi.. Can I removed C1,C3, 7805,. And can still be functioned?

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