Automobile White LED Light

A simple and safe white LED driver circuit has been designed for use in 12V automobiles, allowing for the efficient operation of standard high-efficiency white LED modules powered by automotive battery systems. The circuit utilizes a fixed voltage regulator IC (7805) to maintain a stable output voltage of 5V across capacitor C2. Resistor R1 regulates the current flowing through the white LED D1 (rated at 3.6V and 350mA) with the assistance of transistors T1 and T2, ensuring a constant current supply to D1. It is advisable to attach a suitable heat sink to T1. This LED driver maintains a consistent light output for input voltages ranging from 8 to 18 volts.

The circuit operates efficiently by leveraging the 12V battery supply typical in automotive applications. The use of the 7805 voltage regulator ensures that the output voltage remains stable at 5V, providing the necessary conditions for the white LED to function optimally. The inclusion of capacitor C2 helps to filter any voltage fluctuations, enhancing the stability of the circuit.

Resistor R1 plays a critical role in current limiting; it is calculated based on the desired forward current through the LED. The transistors T1 and T2 are configured to act as a current regulator, allowing the circuit to adjust the current flowing through the LED based on the input voltage. This configuration is essential for maintaining the LED's brightness and preventing damage from overcurrent conditions.

The recommended heat sink for T1 is necessary due to the power dissipation that occurs when regulating the voltage and current. Without adequate thermal management, T1 may overheat, leading to potential circuit failure.

Overall, this white LED driver circuit is designed for robustness and reliability, making it suitable for automotive applications where varying input voltages can occur. The ability to function effectively across a range of input voltages from 8V to 18V ensures that the LED maintains a constant light output, contributing to the safety and visibility of the vehicle.Without any dedicated buck converter/white LED driver IC, you can safely drive many standard Hi-efficient white LED modules using the battery power available in automobiles. Here is a safe and simple white LED driver designed for 12V automobiles. In the Automobile White LED Light circuit, fixed voltage regulator IC1 (7805) provides a steady voltage of 5V across C2.

Resistors R1 limits the current flow through the white LED D1 (3v6/350mA) with the help of transistor T1 (and T2), ie components R1, T1 (and T2) provide a constant current to D1. Use a good heat sink for T1. This LED unit gives a constant light output for input voltages ranging from 8 to 18 volts! 🔗 External reference