How to distinguish the positive and negative poles of a cigarette lighter?

[McHaven]

The center contact of a car cigarette lighter is the positive pole, while the outer contact plate is the negative pole. Below is relevant information about car cigarette lighters: 1. Working principle: In addition to lighting cigarettes, a car cigarette lighter can also be equipped with a vehicle inverter, which converts 12V, 24V, or 48V DC power from the car into 220V/50Hz AC power for use with ordinary electrical appliances. For example, it can charge mobile electronic devices. It is best to use a split-type vehicle inverter, with the power of the electrical appliance limited to below 150W, ensuring the output current does not exceed the battery current. 2. The power voltage of the cigarette lighter is 12 volts, consistent with the vehicle's battery voltage. Typically, the cigarette lighter has a separate power line connected to it and does not share circuits with other lines, thus having a separate fuse. The correct method of use is to insert and remove it vertically without shaking, as frequent shaking during removal can cause looseness and short circuits, burning out the fuse and external devices.