9V Power Supply units (PSU) are a common but important part of everyday electronics. They are commonly used with test equipment in academic & industrial applications. So in this project, we are going to build a 9V Power Supply Using L78S09 Voltage Regulator IC.
L78S09 regulators can provide local on-card regulation, eliminating the distribution problems associated with single-point regulation. It embeds internal current limiting, thermal shut-down, and safe area protection, making it essentially indestructible. If adequate heat sinking is provided, they can deliver over 2A of output current. Although designed primarily as fixed voltage regulators, they can also work with external components to obtain adjustable voltages and currents.
Hardware Components
The following components are required to make a 9V Power Supply Circuit
| S.no | Component | Value | Qty |
|---|---|---|---|
| 1. | Voltage Regulator IC | LM7809 | 1 |
| 2. | Diode | 1N5400 | 1 |
| 3. | DC Supply Input | 12-35V | 1 |
| 4. | Electrolytic Capacitor | 220uF, 47uF | 1,1 |
| 5. | Heat Sink | – | 1 |
| 6. | Breadboard | – | 1 |
| 7. | Connecting Wires | – | 1 |
LM7809 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of LM7809
9V Power Supply Circuit
Working Explanation
The working of this circuit is pretty simple. The heart of this circuit is an L78S09 IC. A 12-35V DC input is taken from a supply that enters the L78S09 Voltage Regulator IC, The circuit will work without the extra components, but for reverse polarity protection a 1N5400 diode is present at the input, and residual noise is removed by Capacitor C1 (200uF).
The L78S09 IC produces a constant 9V DC output. The output from the IC goes through the smoothing capacitor C2 (47uF) to cancel any extra noise, before moving on towards the output.
Applications
- A DC power supply can serve in applications such as applying a variable voltage to DC fans.
- Commonly used in the testing of small electronic projects such as small DIY projects.
