LM338 Power Supply 4-30V 20A

This is a regulated and adjustable power supply that can deliver up to 20A with an adjustable voltage range between 4V and 30V. It is straightforward to construct and utilizes the LM338 voltage regulator.

The adjustable power supply circuit based on the LM338 voltage regulator is designed to provide a stable output voltage that can be fine-tuned according to the requirements of various electronic applications. The LM338 is a three-terminal adjustable linear voltage regulator capable of delivering output currents up to 5A, but with proper heat sinking and additional components, the circuit can be configured to handle up to 20A.

The circuit typically includes the following components: the LM338 voltage regulator, a heat sink to dissipate heat, input and output capacitors for stability, and resistors to set the output voltage. The input voltage should be sufficiently higher than the desired output voltage to ensure proper regulation. A transformer or an AC to DC adapter can be used as the input power source.

To achieve the adjustable output voltage, a pair of resistors is employed in a voltage divider configuration connected to the adjustment pin of the LM338. The output voltage (Vout) can be calculated using the formula:

Vout = 1.25V * (1 + R2/R1) + Iadj * R2

Where:
- R1 is the resistor connected between the output and the adjustment pin.
- R2 is the resistor connected between the adjustment pin and ground.
- Iadj is the adjustment pin current, typically negligible for most applications.

For enhanced performance, it is advisable to include a large electrolytic capacitor at the output to smooth out any voltage fluctuations and provide additional current during transient loads. A fuse should also be incorporated in the circuit to protect against overcurrent situations.

The final assembly should be housed in a suitable enclosure to protect the components and ensure safety during operation. Proper wiring and layout should be maintained to minimize noise and interference, ensuring reliable performance of the power supply in various electronic projects.This is a regulated and adjustable power supply which can deliver up to 20A and adjustable voltage between 4 and 30V. It is easy to build and uses LM338 an.. 🔗 External reference