Stable 5V power supplies are necessary in many electronic applications to power sensors, microcontrollers, and other digital components.
Using the well-known LM7805 voltage regulator IC in a 12V to 5V converter circuit is one efficient method to do this.
Your gadgets will run consistently thanks to this circuit, which takes an AC voltage input of 230V and lowers it down to a reasonable DC output of 5V.
A transformer, a bridge rectifier, filter capacitors, resistors, and indicator LEDs are some of the circuits essential parts.
The transformer lowers the AC voltage 0–12V from the high voltage AC input 230V.
The filter capacitors, one rated at 100µF/25V and another at 0.01µF, smooth out the pulsing DC that the bridge rectifier converts from the AC voltage to provide a consistent output.
This DC voltage is controlled by the LM7805 to produce a constant 5V output that can power attached devices.
Two 330Ω resistors are added into the circuit to restrict current, specifically for the red and green indication LEDs.
These LEDs provide instant input on the power status and function as visual indicators of the circuit’s performance.
Over all, this 12V to 5V converter circuit offers a simple design and dependable operation, making it an excellent choice for a variety of electrical applications.
Below we will go through three ways of 12V to 5V Converter Circuit using IC LM7805 with circuit working, formulas and its circuit construction.
Circuit Working:
Parts List:
| Component Type | Description | Quantity |
|---|---|---|
| Resistors | 330Ω 1/4 watt | 2 |
| Resistors | 1k 1/4 watt | 2 |
| Capacitors | Electrolytic 100µF/25V,10µF 16V, 10µF 16V | 1 each |
| Ceramic 0.01µF | 1 | |
| Semiconductors | IC LM7805 | 1 |
| Transformer | 230V to 0-12V AC | 1 |
| Bridge Rectifier | Bridge Rectifier Module 1N4007 | 4 |
| LEDs | Red 5mm 20mA | 1 |
| Green 5mm 20mA | 1 |
The IC 7805 is available in several package formats, making it suitable for usage in any prototype or PCB board.
Now lets build a 5V DC regulator from beginning.
It is dependable to use the Positive Voltage Regulator 7805, which has a 1.5A maximum current restriction, when you have a 12V to 35V DC source and require 5V.
Three pins make up this integrated circuit: one is used for input, one for ground, and one for output.
Use the appropriate capacitors to connect the IC 7805 so that the input and output are stabilized.
Heat sinks are frequently employed to release extra heat produced during voltage control.
The identical task is completed by all three circuits.
The first circuit is connected between a 5V DC required component and a 12V DC supply.
When voltage is present, it is shown by the second circuit.
An AC to DC 5V regulated power supply, which may function as a stand-alone 5V DC power source, is the third circuit.
Formulas:
The formulas for each of the three LM7805 circuit configurations are listed below.
LM7805 Circuit with LEDs:
LED Current Calculation:
The current flowing through the LEDs may be computed using ohms law.
With a forward voltage drop of about 2V for a red LED Vf and 2.2V for a green LED, assumed the following formulas is used to calculate the current I flowing through each LED circuit:
For Red LED: IR1 = Vin − Vf / R1
For Green LED: IR2 = Vout − Vf / R2
In the circuit design, every element and formula has a distinct function that helps with voltage control, noise reduction, visual cues and overall circuit stability.
It is essential to comprehend these responsibilities in order to design and execute circuits successfully.
How to Build:
3 Ways to Build a12V to 5V Converter Circuit using IC LM7805 follow the below mentioned steps:
- Gather all the components as shown in the above circuit diagrams.
- In the first circuit diagram connect the input pin of IC 7805 with +12V DC input, connect the GND pin of IC 7805 to GND, connect output pin of IC 7805 to +5V DC output.
- In the first circuit diagram connect a capacitor C1 4.7uF from positive supply of +12V DC input to GND, connect capacitor C2 10uF from positive supply of +5V output to GND.
- In the second circuit diagram every thing will remain the same as the first diagram, you just need to connect a resistor R1 1k and LED red in series from positive supply of +12V DC input and GND, and connect resistor R2 1k and LED green in series from positive supply of +5V DC output and GND.
- In the third circuit diagram connect a resistor R1 330Ω and red LED1 in series from positive supply of +12V DC input and GND, and connect resistor R2 330Ω and green LED2 in series from positive supply of +5V DC output and GND.
- Connect a capacitor C1 100uF positive leg to positive supply of +12V DC input and negative leg to GND.
- Connect capacitor C2 0.01uF from positive supply of +5V DC output and GND.
- Connect the positive terminal of bridge rectifier with the input supply line of the 7805 IC, connect the negative of the bridge rectifier to the GND line, connect the AC terminals of bridge rectifier with the secondary 12V wires of the transformer
Conclusion:
In conclusion, because it works with a variety of PCB designs and package types, the IC 7805 is a flexible component that is perfect for building a 5V DC regulator in a variety of applications.
It plays crucial functions in powering electronic components, displaying voltage presence, and supplying independent power sources by efficiently converting a 12V to 35V DC supply to a steady 5V output.
Its performance is further improved by the addition of suitable heat sinks and capacitors, guaranteeing dependable operation in a variety of electrical projects.