The design and application of the relay is relatively simple, and it is generally not a problem to use it according to past experience and the recommendation of the relay supplier. The foundation of power distribution technology based on semiconductor devices In fact, MOSFET-based HSD chips (High side switch) have long been widely used in the control of light loads, relay wire packs and other vehicles with low current loads, but they are limited by HSD chips. Due to the cost and speed of technological development, traditional relays are still used for on-board high-current load control.