The light inside your car that glows up when you open the door of your car is known as the interior light or the doom light. It is an inside cabin light with a dome-shaped cover associated with the roof of a vehicle, vehicle, or car ceiling. In a vehicle it is viewed as a security feature, however, generally fits as standard.
Your doom light enlightens the interior cabin of the vehicle, making it simpler to peruse, and helps to affix your safety belt at dark and discover anything you may have dropped. Your doom light additionally illuminates and indicates your entryways or doors are opened, in this manner telling you or warning you whenever your entryways or doors and luggage cabin aren’t shut appropriately.
This car doom light circuit can be utilized in any vehicle that utilizes a 12V battery. The circuit uses 12 LEDs with a blend of resistors and capacitors. Additionally, the entire circuit is controlled by utilizing LM2940CT-12 a voltage regulator IC to manage the brightness of LED irrespective of engine activity.
Hardware Components
The following components are required to make a Car Doom Light Circuit
| S.no | Components | Value | Qty |
| 1. | Voltage Regulator IC | LM2940CT–12 | 1 |
| 2. | Electrolytic Capacitor | 100µF, 33µF | 1 |
| 3. | Battery | 12V | 1 |
| 4. | Resistor | 120R | 4 |
| 5. | LEDs | – | 12 |
LM2940-12 Pinout
For a detailed description of pinout, dimension features, and specifications download the datasheet of LM2940CT-12
Car Doom Light Circuit
Working Explanation
The core of this retrofit circuit is LM2940CT-12 IC. The LM2940CT – 12 is a positive voltage regulator IC. It can furnish 1A of output current with a dropout voltage of ordinarily 0.5V and a limit of 1V over the whole temperature.
It utilizes twelve 25mA very brilliant white or blue LEDs. The circuit is likewise a battery saver in contrast with the ordinary light utilized in cars. The vehicle battery voltage increments to 14V when the engine is running and tumbles to 12. 6V when the engine isn’t running, this makes the LEDs become extra bright when the engine is running and gets diminished when the engine is off. To dispose of this issue an LM2940CT-12 voltage regulator IC is utilized in this circuit. The IC gives steady and precise 12 volts to the LEDs in the bot operations because of which the LEDs won’t become extra splendid or diminish with engine operation.
Applications and Uses
- Dome lights intend to enlighten driver and passenger compartments including the storage and trunk areas.
- They can likewise be utilized to control windows and sunroofs just as emergency call buttons.
- It likewise shows whether your vehicle’s entryways or doors are appropriately closed or not.
