Variable Power Supply

9,333

Circuit Image

Using the versatile L200 voltage regulator, this power supply has independent voltage and current limits. The mains transformer has a 12volt, 2 amp rated secondary, the primary winding should equal the electricity supply in your country, which is 240V here in the UK. The 10k control adjusts voltage output from about 3 to 15 volts, and the 47 ohm control is the current limit. This is 10mA minimum and 2 amp maximum. Reaching the current limit will reduce the output voltage to zero.

The circuit utilizes the L200 voltage regulator, which is known for its ability to provide both adjustable voltage and current regulation. The L200 is capable of delivering an output voltage ranging from approximately 3V to 15V, making it suitable for various applications. The adjustment of the output voltage is facilitated by a 10k ohm potentiometer, which allows for fine-tuning based on the requirements of the load.

The power supply design incorporates a mains transformer with a secondary winding rated at 12V and 2A. This transformer is crucial as it steps down the mains voltage (typically 240V in the UK) to a lower, usable voltage level. The primary winding of the transformer is connected to the mains, while the secondary winding provides the necessary voltage to the L200 regulator.

In addition to voltage regulation, the circuit also features a current limiting mechanism, implemented through a 47 ohm resistor. This resistor sets the maximum current output to 2A, while allowing a minimum current of 10mA. The current limiting function is critical for protecting both the power supply and the connected load from excessive current draw, which could lead to overheating or damage.

An important characteristic of this power supply is that when the current limit is reached, the output voltage will drop to zero. This feature ensures that the load does not draw more current than the specified limit, thereby maintaining safe operation.

Overall, this power supply circuit is designed for versatility and safety, providing adjustable voltage and current outputs suitable for a wide range of electronic applications. Proper component selection and configuration ensure reliable performance while adhering to electrical safety standards.Using the versatile L200 voltage regulator, this power supply has independent voltage and current limits. The mains transformer has a 12volt, 2 amp rated secondary, the primary winding should equal the electricity supply in your country, which is 240V here in the UK.

The 10k control is adjusts voltage output from about 3 to 15 volts, and the 47 ohm control is the current limit. This is 10mA minimum and 2 amp maximum. Reaching the current limit will reduce the output voltage to zero. 🔗 External reference