Change the Output Voltage of SMPS

ABOUT THE TUTORIAL:-

In this tutorial I am going to show you how we can convert a 12V SMPS into A 5V one. So Let's get started!

WARNING ! "The circuits showcased in this tutorial are powered by Mains 230V/50Hz mishandling of such a high voltage can lead to fatal injuries."

NECESSARY TOOLS & EQUIPMENTS:- in order to learn something new by this tutorial we need the following hardware-

- 12V-2A SMPS(switch mode power supply)

- Screw driver

- Soldering Iron

- solder wick or desolder pump

- soldering wire

- 10K quarter watt resistor - 2

- 1K resistor - 1

- 180 ohm resistor - 1

- 100 ohm resistor - 1

- Digital multimeter

FOLLOW THE STEPS PATIENTLY:-

Step - 1

first of all power the 12V SMPS by Mains Voltage (230V/50Hz In INDIA). and then measure the voltage across on Vref pin of TL431 in my case the value of Vref is around 2.493V(2.5V)and also measure the voltage across 2K resistor. In my case the voltage across the 2K resistor is 1.026V so we have to select new value of resistors in such a way that when we get an output voltage of 5.012V , the voltage on the Vref pin Must be the same as before and also the voltage across the PC817 optocoupler must be the same as before. the value of resistors for 5V output has been given in the the one of the pictures of this tutorial. but if your SMPS has a different output voltage then you have to calculate the accurate values of the the components using ohm's and kirchhoff's voltage rule if you are not familiar with these two basic rules of electronics & electrical engineering then first you need to study these rules carefully.

Step - 2

In second step we will remove the flyback transformer from the SMPS circuit with the help of sodering iron and solder wick. when you remove the flyback transformer first chekout that your circuit must be disconnected from mains supply and all the high voltage capacitor must be discharged otherwise you may get an electric shock. after successfully removing of the flyback transformer. now it is the time to remove the ferrite core of the transformer but first thing that is need to keep in your mind is that core of the the flyback transformer gets broke with a small force. to remove the core carefully you can heat the core of the transformer by bringing the tip of your soldering iron in contact with the core so the core temperature will increase and glue of the the core will loose and then you can remove the core by pulling the each side of core with a cloth. and when you are done here follow the next step.

Step - 3

In third step we remove the secondary winding of the copper wire and after removing the secondary winging we will rewind the secondary winding using the same wire but this time we have to calculate the number of turns for secondary winding to get the output voltage of 5V. you can see my calculations in the pictures of this tutorial. Step - 4

In step 4th will reconnect the ferrite core with the former of the transformer and also use glue to stick the ferrite core.

Step - 5

This is the last step of this tutorial and in this step we have to solder the newly winded flyback transformer and after soldering you are done here.

now it is the time to test our new SMPS. and then connect it again to mains and also measure the output voltage with a digital multimeter and if your multimeter gives the voltage value 5V then your aim is achieved by you and now it's time to connect a load to your SMPS in my case the load is a 12V/25W Bulb

PURCHASE THE ELECTRONIC COMPONENTS:-

Quartz Components:-

10k resistor -

https://quartzcomponents.com/products/10k-ohm-1-4-...

100 ohm resistor-

https://quartzcomponents.com/products/100-ohm-1-4-...

1K resistor -

https://quartzcomponents.com/products/1k-ohm-1-4-w...

180 ohm resistor -

Amazon:-

12V-2A SMPS -

https://www.amazon.in/SunRobotics-Industrial-Appli...