At present, the electric heaters of split heating and cooling air conditioners on the market are basically made of ceramic PTC electric heating elements. Ceramic PTC will have an inrush current at the moment of starting. In order to ensure the safety and reliability of the control circuit, the existing control method uses two electromagnetic relays with the same rated current value and greater than the inrush current value in the control circuit for synchronous control. Due to the short duration of the impulse current and the small steady-state current, a new type of "time-sharing control technology" was proposed to reduce the capacity of one of the relays, so as to reduce the cost on the premise of ensuring the electrical safety of the control circuit.
