Top Power supply circuit diagram

You are looking for many power supply circuit diagrams, right? Because the various electronic projects need to use them as an energy source.

These listings below may help you choose the type to match your usage, also most of them are cheap and easy to build. But most importantly is the ideas you could get out of them.

Learn Top Power supply circuit diagram on

3 Power Source for Electronic Devices

Let’s look at the three most used types of Power Supplies.

Types 1# Battery

A lot of circuits use a little power. So, it can be powered by batteries. The battery is small and easy to use anywhere. But normally they are low voltage. Thus, they are the best uses for low current loads.

But for a heavier load, what should we do?

Rechargeable batteries are a better answer. Can be reused many times to save a lot of money. I like having my children use them.

Type 2# Solar

We can use the solar cell to power our circuit directly. But usually, we like to use it as a battery charger for a rechargeable battery. For example, a battery charger inside a solar light, etc.

Type 3# AC Line

The AC line we currently used is the main source. Often through an AC Adapter as a power supply. They are more compact and easy to use than the battery.

We can adjust its output to various voltage and currents.

When we are at home. We should use them instead of batteries and solar. Because it will save our money replacing our batteries when it is dead and convenient, no need to wait for sunlight when using a solar cell.


We must use it carefully. It is many useful but also can kill you! Safety first!

Why should we use a linear power supply?

There are many kinds of power supply circuits. But they can all be put into two groups.

  • Linear Power supply
  • Switching mode power supply

How does the linear power supply work?

The AC voltage that goes through a power transformer will be raised or lower depending on the type of the transformer, and then converted to DC voltage. Next, the voltage will go through the regulator circuit system to keep the voltage and current stable for a load.

The explanation above is oversimplified if you want in-depth information. Click here

How does the Switch-Mode Power Supply work

It does not contain a big-size transformer instead it directly converts the AC power into a DC voltage. Then, this DC voltage is converted back into an AC signal with a higher frequency than before.
And, the regulator circuit inside will produce DC voltage and current as desired.

The difference between linear and switch-mode power supply

The table below compares various parameters of linear and switching forms.

Linear VS Switching DC Power Supplies

Thanks: Tekpower 30V 5A Supply

30V 5A Linear Power Supply

I love the linear power supply. Why?

They are:

  • Easy to understand a circuit diagram
  • Quiet
  • High stable, durable and heavy-duty
  • Low noise, ripple, delay, and EMI

The switching type is all but just the opposite.

UPDATE: But now I also love it. Because it is better than the linear for its higher efficiency, cheaper, smaller, etc. Causing it to be more popular than before. You may love it with me.

Still curious? Click here to find out: Basic AC-DC Power Supplies

Power Supply circuit Expalintion

If you are a beginner, I know that you do not want to waste time learning principles, and want to create a power supply circuit quickly.

But you should learn its working principles at least once. To reduce mistakes and select the circuit appropriately for your usage. It will make your life easier.

Step 1. Principle of Unregulated Power Supply

Unregulated power supply circuit

Almost all circuits are based on this principle. So, you should read it beforehand.

Step 2. Principle of Fixed Voltage Regulator

Even though we do not like complexity. But every project needs good stability. So, this is necessary!

Step 3. Overload and short circuit protection

Let’s learn about the transistor series voltage regulator with short circuits and overload protection. And how it reduces ripple.

Step 4. How 741 Op-Amp Power supply Circuit works

Learn an error voltage sensor using transistors circuit work inside of variable voltage regulator using 741 and 2N3055.

Step 5. How to increase current using transistor

Learn how to increase/boost up current of 7805 (or 78xx) regulators with helping the 2N3055 and others transistors.

12V 5A DC Power Supply design

Top 8 power supply circuits

On our site have a lot of power supply circuits. We can not show it all to you. Thus, for saving you time see the lists below.

Top 100 power supply circuit

1# My First Variable DC Power Supply

LM317 Power supply circuit 1.2 to 30V 1A

You can adjust an output voltage from 1.25V to 30V at 1.5A.  I like this one.  Because… It is easy and cheap. For example,  You can use it instead of a 1.5V battery. 

Let’s create your first power: LM317 Power supply

Read also: LM317 pinout and how to use, Calculator Datasheet

2# Simple Fixed voltage DC regulator

TransistSeries Voltage Regulator circuit

We often found this circuit in many appliances. They are quite old circuits but still have many uses.

It is very simple with just one transistor, Zener diode, and resistor. The output voltage depends on the Zener diode. For example, if we want a 12V output, then use a 12V Zener diode.

Let’s Create Simplified Transistor Series Fixed Voltage Regulator

3# 78xx voltage regulator

Many Fixed Regulator Circuits 5V,6V,9V,10V,12V 1A using IC-78xx series

78xx is a popular 1A fixed DC Regulator. Because of easy to use and cheap. And the output depends on the IC. If you need a 6V 1A output for a digital circuit, then the LM7806 is your pick.

Also Learn: 7805 voltage regulator circuit, pinout, and more

4# 3A Adjustable Regulator using LM350

LM350 Voltage regulator datasheet
LM350 adjustable voltage Regulator

I sometimes need to use 3A variable voltage source.


LM317 cannot help me, easily.

In a short time, we use the LM350 Variable regulator.

It is the best linear IC@3A. The output is 1.25V to 25V.

5# 0-30V, 3A Adjustable DC Supply

0-30V Variable Supply at 3A

We seldom use 3A Current that can adjust 0V to 30V output. This is a better choice.

It uses LM723 as the famous regulator IC and Power transistor, TIP3055

And here is a modern design circuit, full protection than LM350T.  

6# 0-50V Variable supply @3A

0-50V 3A Variable supply

If you need to use the output voltage over 30V or adjustable from 0V to 50V. It has a key component of LM723 but for the higher voltage, the 2SC5200 transistor is also needed. With full overload protection.

7# Build 12V 2A power supply with a hammer

Creating a simple 12 volts supply with hammer

If you hurry up and have no PCB. This idea may good. You can build a 12V 2A adapter easily and cheaply.

By using a hammer and snail on the wood board.   Also, to learn more. 

8# 15V Dual supply for Preamplifier

Dual 15V Power Supply circuits With PCB, +15V -15V 1A

If you need to use many circuits using OP-AMP. For example, Preamplifier with tone control and more. They need to use +/- 15V regulated supply. We have 3 circuits using 7815-7915 and transistors 


Other Linear Power Supply Circuit Diagram

Fixed Volts regulator:

Adjustable Power Supply Circuit

What is a variable power supply?

Simply said it is a power supply that can adjust the output voltage or current. But it still has the same characteristics as a fixed regulated circuit. It will keep a stable voltage when it has any load.

Start with: Simple Variable power supply circuits

  • 0-70 volts 2 Amps DC variable —look at Here
  • Cheap DC adjustable 0-30V 2A Laboratory —look at Here

Switching Mode Power Supply circuits

These are DC switching power supplies. To are ideas on building the projects or tools. Because they have a small size and are cheaper than the linear version.

What is switching power supply how does it work

Learn more: 

My site begins to have many circuits. Until friends said that difficult to see circuits or projects as he wants.

A particular DC switching power supply is very useful. The list below is idea to build a great power supply that is small and saves money. For application or learning.

So, I collect these circuits for ease of accessing the projects that I am interested in. Also, they may be useful for you, too.

Switching Mode regulator

DC to DC converter



I always try to make Electronics Learning Easy.

Get Ebook: Simple Electronics Vol.4

15 thoughts on “Top Power supply circuit diagram”

  1. I am lost, I need 1.5 volt battery P.S to light two 1.5 v miniature lights for my Buddy L trucks.The lights I have are 1.5 v, .3 amp. these could be wrong. Is there a better choice. HELP ?

  2. PS, USB 5vto 1.5v step down converter circuit, I think this one will work, I require 1.5 v battery source PS to light two 1.5 v miniature lights for my Buddy L. Do I purchase everything from you how does it work ?

      • i MADE A MISTAKE PLEASE READ 2022 and not 1022
        I need the diagram of this power supply to repait my unit. This power supply is formy TX/RX radio, i need 13.8 volts 20 Amps, According advertisement i have bought a new one (Nissei PS30SWII) quite cheap 95€, but I want to get the old one repaired and to use in in my workshop.

  3. hello sir,
    i have to make an led strip driver of 12v 5amps 60w please help me to make it with smps transformer
    please help me

  4. Hello, I own an internet tower and I want a multi-volt electronic circuit to be an alternative to the inverter and use transformers. I want an electronic circuit to convert from 12 volts to fixed multiple voltages 9v, 12v and 24v and the main voltage source is the use of a battery

    • Hello Hussain,
      I glad that you are interested in these circuits. You should probably use a DC to DC converter as a Switching mode power supply circuit. I’m also interested in learning about this kind of circuit. In the future, I will publish it on the web.

      Ah… What is the current size of the load? If the load uses less current We choose a simpler circuit. and smaller.


  5. I’m always burning the me in lm317 .I use the transformers of 220 ac/24ac . And it keep connection it right according the schematic I use just like in the example this

    • Hi,
      The maximum input voltage for the LM317 is 40V. Yes, you can use 24VAC transformer. When it changes DC voltage, the voltage level must not exceed 40V. In my experience, transformers with voltages that are too high. Until the problem mentioned in the article occurred.

      You may encounter the same problem as me, or in another case, you may encounter a low-quality LM317 that cannot handle voltages as high as 35V. I used to use an LM317 that couldn’t handle voltages above 30V. It would get very hot.


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