DIY - CHEAP POWER SUPPLY (Without Transformer)




Posted in TechnologyElectronics

Introduction: DIY - CHEAP POWER SUPPLY (Without Transformer)

About: I Make Simple.

Please it's very lethal . You can't handle this without care if you do you will die i make sure !

Hi, this i time i came up with a very cheap power supply it's NOT for beginners!. They used to make simple things like some lights or any moving thing with motors they cause use this power supply in complex circuit as well cause it's quiet safe but not much so careful. You will need some simple components like capacitors and diodes. They will cost you around 10 to 20 dollars or around 80 rupees. You can make it at home !

Step 1: Fetching Parts!

You need a couple of components which you can get at a nearby electrical workshop or from radioshack. These are listed below :

1. One ceramic capacitor of 250 volts and 1 micro-farrad . The value of the capacitor should be 105.

2. Five IN4007 diodes . You need to make a diode bridge using four of them and one should be used for another purpose.

3. One Zener diode with the zener voltage o 5 volts.

4. One LED as indicator.

5. One resistor . the value should be around 500 OHMS.

6. One Electrolytic Capacitor of value 470 micro-farrad and of voltage 5volts.

7. One 400k resistor.

Step 2: The Main Circuit

Here's the main circuit. All assembled with no errors . It don't get hot even when you make it work for 10 hours or more.

Step 3: The Finished Product.

Here is the complete assembled circuit with low dc voltage out!



    • Microcontroller Contest

      Microcontroller Contest
    • Make it Move Contest

      Make it Move Contest
    • Casting Contest

      Casting Contest

    We have a be nice policy.
    Please be positive and constructive.




    India has one of the worst standards for safety...please dont build this.

    5 replies

    Bad to say you're right but we also produce the best Appliances with the best security standards and even the governmental factory just near my home it produces one of safest appliances in the world with no errors ! yup, no problem here.

    This is the way anyone cannot do see the man's mind that in over 1000 wires he is repairing his wire's connection and see his bravery it's dangerous but it's the work of braves! and think think how many wires he has to sort out of this it's not a work of intelligent but i can only by an intelligent!

    I'm sorry, I don't understand what you are trying to say. All I can say is that unsafe practices are never intelligent or a good idea.

    Perhaps it's right and i can't refuse it but there are still some places in which you can find best security measures other than in any parallel or our "universe".


    "I got this circuit from and chinese led lamp" -- not the place to be learning how to correctly and safely build a mains power supply.

    All other worries aside, the 250v capacitor is underrated, you don't actually think that a 250v supply only has 250v there? The peak voltage is higher, never mind all the spikes from devices switching on and off. 400v capacitor maybe. And not some cheap ceramic disc scavenged from a project.

    Power supplies like this are fine IF designed correctly (this one isn't), AND entirely enclosed (it's not) AND the output isn't connected to anything "outside the box".

    3 replies

    But i've correctly metioned it's cheap! I build it cause it's pretty cheaper to me i am not going to buy one transformer insted of that i should prefer to buy one capacitor!

    But i've correctly metioned it's cheap! I build it cause it's pretty cheaper to me i am not going to buy one transformer insted of that i should prefer to buy one capacitor!


    And when C1 does eventually short out, C2 will turn firecracker ...

    Well, some things look dangerous but they aren't. I made many water heaters using two 220 V electrodes (carbon or stainless steel) partially covered by a plastic net. I used them for many years, I put even my fingers into the water to demonstrate it is safe, but many persons are scandalized.

    Also you have to take into account the voices of alarm are very CONTAGIOUS.

    2 replies

    Yah! you are right i also use you method but i didn't dared to put mu fingers in!

    Even you can use a metal container for the water. In this case maybe you could feel a little "tickle" touching it, but never you feel a shock, provided that none of the electrodes touch the metal. The key is to do the heater well isolated.

    My turn.

    Direct coupled mains (power) devices such as this are very dangerous. It must be fitted in an electrically isolated enclosure (plastic, perhaps). No external contact should be possible. Also heat build-up in the device should be considered. However, the concept is not wrong as it almost directly copies such mains powered devices. Correctly, the most concerning aspect the author has made (other than originally describing it as a "beginners" device) is to make it all physically accessible. Devices of this nature really should be made so that you cannot touch any part of it. A transformer would be so much simpler and would not require high voltage rated parts which, for long term reliability, are somewhat expensive. If you do decide to build this device, be very careful. Electric shock is rather painful and electrocution would most likely be worse (can't comment from experience as whilst I have received shocks, I am still alive - not electrocuted). Also to Rimar:; Please be careful with electricity. I value you & your insights. I would grieve if something happened to you. That applies to everyone here.

    oh well, we tried to warn him, but he seems hell bent on winning a darwin award.

    Sorry Samaddon, but as you are 15, I dont think you are in a position to advise on electrical safety.

    and Rimar, stop encouraging him, thats naughty ! Sure your water heater would work, and may be safe ish if you happened to put your fingers near the ground electrode, but what happens if you put them near the live one, with your other hand touching earth potential ? hurts a lot doesnt it ? :)

    We all need to learn, and i dont want to put samaddon off his experiments, but sometimes serious errors have to be pointed out before a very avoidable tradgedy happens.

    1 reply

    Do you know in my country (INDIA) there are million of house who are using the power supply for general low voltage power supplies. I got this circuit from and chinese led lamb for emergency . there are millions of those lams sold freely in india!

    Only one thing to say NO! DON"T !!!!!!!!!!
    Never do this ,safe power supplies are too cheap to risk life !
    I have worked in electronics for over 40 years & I wouldn't build this ...

    Now all of you are satisfied!
    Thank you for warning me but i was using this power supply for years since i was 6only and now i am 15!

    It has already be noted that this is dangerous, it is so dangerous that I will repeat the warning. This is not a good idea for almost anyone. It also is not a very good supply even ignoring the dangers. I would recommend that the author remove it entirely. Trying to be as nice as I can, but safety requires some honesty here, sorry.

    I really want to say something nice, but this is really lethal, theres no mains isolation, and if C1 goes short it will fry anyone and anything that is connected.

    you say its cheap - yes although the component cost if new is about the same a a ready built (safe) 5V PSU on ebay. You also say its good - sorry it just isnt !