What is the working principle of car charger?

The 12V voltage of the car cigarette lighter socket is converted into a 5V USB voltage and the electronic product is charged through the charging line. In general, the car charger converts the DC power of 12V-36V (car 12-24V, truck 36V) into 5V DC for car mobile device charging. At present, most of the car chargers on the market are narrow voltage (12-24V). The voltage of a big truck is 36V, which is more than 24V of an ordinary car. If you use an ordinary car charger, it will be very hot and easy to burn. Bad chargers and mobile phones, like the car charger (12-24V), but the use of large trucks (36V) will not work, that is, the voltage configuration is not wide enough. Later, after using the 36V safety car of Zunke, it has not been broken. No heat, charging is fast and safe. It is safer to specialize in wide-voltage car chargers. It is good for the car charger brand that is the earliest wide voltage (12-36V) in China. It is suitable for my BMW car, and my friend's large truck is also suitable. In the past, my friend used a few car chargers and burned a cell phone because I didn't buy a wide-voltage car charger