9V/5A regulated Power Supply units (PSU) are a common but important part of everyday electronics. They commonly serve with test equipment in general & industrial applications. So, in this project, we are going to build a 9V/5A regulated Power Supply Using LM7809 Voltage Regulator IC.
LM7809 regulator IC is a common but an important part of much 9V power supply circuit. LM7809 is a 9V Voltage Regulator that restricts the voltage output to 9V and draws 9V regulated power supply. The LM7809 is the most common, as its regulated 9-volt supply provides a convenient power source for most TTL components. It offers features such as internal current limiting, thermal shut-down, and safe area protection, making it essentially indestructible.
Hardware Required
You will need the following parts to build this project
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Stepdown Transformer | 230V/12V 5A 50Hz | 3 |
| 2. | Regulator IC | LM7809 | 3 |
| 3. | PNP Power transistor | TIP2955 | 1 |
| 4. | 10A Bridge Rectifier | 50V PIV | 3 |
| 5. | Capacitors | 3300uF/50V, 0.33uF, 10uF | – |
| 6. | Resistor | 10hm/2W | 1 |
| 7. | Breadboard | – | 1 |
| 8. | Connecting Wires | – | – |
| Pin No. | Pin Name | Description |
| 1 | IN | A positive voltage is given as input to this pin. |
| 2 | GND | Common to both Input and Output. |
| 3 | OUT | Output regulated 9V is taken at this pin of the IC. |
Circuit Diagram
Working Explanation
An input voltage of 230V is applied at the primary of the transformer which steps it down to 12V 5A through mutual induction of the primary & secondary windings while maintaining the frequency at 50Hz. After which the 12V AC signal goes through a 10A bridge rectifier which converts the AC signal into a rippling DC signal.
The DC signal then passes through smoothing capacitors C1 (3300uF) before passing on to an LM7809 voltage regulator IC which produces a constant 9V/5A DC signal at the output. Here, the TIP2955 transistor boosts the output voltage of the LM7809 IC. The output DC signal passes through a smoothing capacitor C2 (10uF) before moving on towards the output.
Applications
- DC power supplies are widely in use in low voltage applications such as charging batteries & automotive applications.
- It also serves in places such as aircraft and other places with low voltage, low current applications.
