[The cooling fan] without polarity protection will burn if the polarity is reversed?
Some cooling fans do not have terminals that prevent reverse polarity insertion, that is, two wires are endless and use wire bonding. Then, if we weld the cooling fan and the polarity is reversed, will it be burned right away? This mainly depends on the chip 1. Some chips have shock resistance, even if the polarity is reversed, they will not burn instantly, but the current will be much higher than normal, which will increase the temperature of the motor, and the temperature will rise to a certain level, which will cause Chip thermal breakdown burn-in 2. Some chips have no protective effect. Once they are connected reversely, the chip will smoke immediately, causing burn-in. When using this type of IC, the cooling fan manufacturer will generally tell the customer to add as much as possible If the terminal is inserted reversely, it will not be inserted into the terminal block to prevent burning.