+12V,-12V power supply using LM7812,LM7912

Here is circuit Power Regulator +12V,-12V. Use IC –LM7812 for +12V and IC LM7912 for -12V. This is circuit for Preamplifier play nice Music.Detail See in circuit.

I plan to show you, with an interesting concept.When I was make pre-amplifier circuit is small. I did not plan on the power supply. It requires low supply current is only 100mA. But the need for dual voltage. Or 3 line is +12 V,-12V and Ground. At that time, I have not the least knowledge and a few equipments. The regulator ICs I use IC7812 and IC7912 (hard to bought). I make this circuit. It works great.
notice point
In circuit I use diodes D1, D2, only both because I’d forgotten to add, and this is a low current, using a half-wave diode rectifier enough. and The transformer is 300mA -15V CT 15V that cheap than other sizes.
-IC1-IC2 do not need to hold the heat sinks because the very low currents.
-LED1 is indicator to Power ON that R1 is the current limiter of LED1.
-C1,C2,C3,C4 are first filter that time I has them many so place various 2200uF.

Click to read information

How to built.
This project I put them in peforated board, it easy to use, and so cheap. But at time I put wrong pin capacitor, when entering the power supply, causing it to burst. I was shocked very much.But I do not Discontinued this project.
All my experience, when I was young. About building electronic circuits.
Thank you for reading the poor English story.

Power Regulator +12V_-12V by 7812 , 7912

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4 thoughts on “+12V,-12V power supply using LM7812,LM7912”

  1. Appreciable!!!
    But u dint explained the design nicely…How u have calucalated the value for capacitor?? And working of circuit also..??

  2. Dear Team,
    I have 2V/500Ah cells (24nos) in a place for running a equipment and for auto generation of DG I am keeping 12V/120A battery, I want to avoid this DG battery (12v/120Ah) need circuit for this.

  3. dear sir

    one project develop my self is 3.2 volt series led light ( power led used). 29 nos.
    and transformer less power supply for 225 k/4oo polyester capacitor circuit developed.
    but led is does not continuous working.
    its only 480 hrs. runing and led circuit problem
    so please suggest to me. any idia for circuit


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