How to build a 5V Regulated Power Supply Circuit with IC 7805

Introduction

‘5V Regulated Power Supply‘ assembling as our first project work in our blog is our hot discussion today. In this post, we intend to discuss the assembly of  ‘5V Regulated Power Supply Circuit’ in depth, so that the readers, novices and electronics enthusiasts would like to sharpen their skills and experience the building of this versatile power supply circuit as a DIY project.

In electronics, for any circuit to function properly, a proper and appropriate power supply is always needed. Poor and substandard power supply systems may produce low performance of the function, and be unsafe for the circuit design. The circuit elements may get damaged or break down if the quality of the power supply is not standard. A well-regulated power supply will deliver optimum performance of the circuit.

This is absolutely correct and highly necessary in operating digital electronics logic circuits. In the electronics mart, a variety of power supply systems are available for the operation of digital circuits. There are circuit designs starting from a half-wave rectifier to versatile SMPS power sources available. An ordinary power supply should not be used for digital circuits.

Do you know what the vital power supply is needed to operate the digital electronics logic gate ICs?. Mostly, 5V regulated power supply is essential and can be easily obtained from a well-designed power supply. In olden days, a regulated DC supply was obtained using discrete power transistors. Nowadays, the design has been simplified and more specifically well-regulated and safe power supply systems can be built using regulated ICs. We too require such regulated efficient power supply as our lab bench power supply to test and do experiment with digital logic gate IC circuits.

Salient features of the 5V regulated power supply

1. 5V regulated power supply as DC output
2. Constant current supply
3. Safe for operation
4. Economical and affordable to build and use
5. A beginner-friendly circuit design

In the electronics mart, a variety of regulated power supply circuits are made available. Though one can procure one and use it. However, the quality of the design and longer lasting for continued operation is doubtful apart from exorbitant cost of such power supplies. You will find power supply systems, some use half-wave rectifiers with low quality filtration and smoothing. This may be harmful for the digital ICs and results poor performance. As such one can build your own well regulated power supply by procuring quality components at affordable cost.

Assembling 5V regulated power supply circuit is not as difficult as we think off and I am explaining here a simple, easy to assemble circuit design using an IC for our practical tests in the experimental section. It is described as DIY project. It is cost effective, reliable and beginner-friendly.

IC 7805 Voltage Regulator

Pin configuration : Pin 1 = Input, Pin2 = Ground, Pin3 = Output. 

Voltage regulator IC 7805 is a 3-pin package and it can be used straight away in the power supply circuit. It is easily available and affordable to buy. It is easily accessible for hobbyists and professionals alike.
The regulator IC gives reliable performance: The IC provides stable voltage regulation, with built-in protection features like thermal shutdown and short-circuit protection.

The Input Voltage Range is wide. The 7805 can accept a broad range of input voltages, typically from 7V to 35V, making it versatile in various applications. The output is 5V regulated power supply. The power IC dissipates excess energy as heat. This can be inefficient, especially when the difference between input and output voltage is large. A heatsink may be required for higher current applications.

Circuit schematic

A simple and at the same time versatile 5V regulated Power supply circuit giving steady 5V for efficient use of digital circuit is given here. Full wave rectification of AC supply ensures capable of delivering nearly 1A power is utilised. Even after smoothing the DC supply, it has been specifically regulated to 5V DC output with the help of the famous voltage regulator IC 7805. It is a simple 3 pin IC voltage regulator easy to handle and assemble on PCBs.  The full circuit schematic is given for your appreciation and assembling. 

Working of the circuit

Now we will discuss how the 5V regulated power supply circuit is functioning. PT is the power transformer that reduces 230 V AC to 8 V AC in its secondary, which is potentially rectified to a DC voltage by the full-wave rectifier diodes D1-D4. One may use a bridge rectifier also in place of 4 nos. of individual diodes. The pulsating DC is smoothed by C1 and fed to pin 1 of the Voltage Regulator IC 7805. The IC delivers a constant +5V regulated DC supply at its output pin 3, which is further filtered by C2. Pin 2 is grounded and is connected to the -ve power supply.

Parts List

Very few components are used in the 5V regulated power supply circuit. The details of the parts are given below.

Item Number	Item	Quantity
U1	IC 7805	1
D1, D2, D3, D4	IN 4002 Rectifier Dodes	4
PT	230 V to 8 V AC Step Down Power Transformer	1
C1	2200 MFD/25V Electrolytic Capacitor	1
C2	220 MFD/16V Electrolytic Capacitor	1

Read also : ‘Circuit Elements for successful project building.’

Assembling 

Since the associated components are very minimal, the 5V regulated power supply circuit can be easily assembled on a general-purpose PCB. However, if one wishes to build the circuit on a ready-made PCB, the PCB design may be made by oneself or can be procured from the market. Ready-made PCBs are available. It is noteworthy to note that the power supply PCB can be fitted to any gadgets that require a regulated 5V power supply. One can easily assemble this PCB with the help of the circuit as a DIY project. The assembling cost may be minimal if procured as a kit form from electronics shops from your town. 

Ready made PCB Pattern 

An illustrative PCB pattern is shown in the figure.

The PCB design can be traced and one can etch a copper clad board for self use. The technique is simple one and can be ascertained from videos available in You tube.  

Conclusion

The versatile 5V regulated power supply is very handy for electronics enthusiasts like hobbyists, prototype builders, experimenters, electronics students and even professionals. This voltage regulator is very essential for our digital electronics lab experiments. Hence, please build your own 5V regulated power supply unit for your digital electronics projects as well as to experiment Logic Gates, which I am going to be discussed in this blog step by step. It will be an added advantage to learn digital electronics with confidence. Kindly express your comments here, so that the peoples’ requirements can be ascertained and act accordingly.