Automotive relay contact selection and performance optimization

In automotive circuits, relays play a vital role as control elements. They can not only isolate and protect the main circuit, but also realize automatic control and remote operation of the circuit. Among the many parameters of the relay, the contact load capacity, contact form and number of groups, and the choice of contact materials directly determine the applicability and reliability of the relay in the automotive circuit.

Contact load: the limit of the control circuit
The contact load capacity is an important indicator to measure the maximum current and voltage of the circuit that the relay can control. In automotive circuits, different loads (such as light bulbs, motors, solenoid valves, etc.) require different currents and voltages. Therefore, when selecting a relay, it is necessary to ensure that the contact load capacity of the relay is greater than the actual load current in the automotive circuit to prevent overheating, welding or ablation of the contacts, thereby ensuring the stable operation of the circuit.

It is worth noting that the contact load capacity depends not only on the size of the current and voltage, but also on the type of load (such as resistive, inductive or capacitive load). Different types of loads have different current shocks and arc phenomena when they are connected and disconnected, and the degree of damage to the contacts is also different. Therefore, when selecting a relay, you also need to consider the type of load to select the appropriate relay model.

Contact form and number of groups: adapt to diverse needs
The control requirements in automotive circuits are diverse. Therefore, when selecting relays, you also need to select the appropriate contact form (such as normally open, normally closed, conversion, etc.) and number of groups according to actual needs.

Normally open contacts are in an open state when the relay is not powered on, and closed after power is supplied; normally closed contacts are the opposite, closed when the relay is not powered on, and open after power is supplied. Conversion contacts can switch between two circuits when the relay is powered on. These different contact forms can meet different control requirements in automotive circuits.

At the same time, according to the complexity of circuit control, relays with multiple contacts can also be selected. Multi-contact relays can realize synchronous control of multiple circuits, simplify circuit structure, and improve control efficiency.

Contact material: the key to determining the life of relays
The performance of contact materials directly affects the electrical life and mechanical life of automotive relays. High-quality contact materials should have low and stable contact resistance, excellent corrosion resistance and anti-adhesion properties.

Contact resistance is an important indicator to measure the contact performance of contacts. Low and stable contact resistance can ensure that the circuit will not produce excessive voltage drop and heat loss when it is connected, thereby ensuring the stability and reliability of the circuit.

Corrosion resistance refers to the ability of contact materials to maintain their stable performance in harsh environments such as humid and corrosive atmospheres. Anti-adhesion refers to the ability of contacts to separate quickly when disconnected without adhesion, thereby ensuring reliable disconnection of the circuit.

In order to obtain better contact performance, many relay manufacturers use high-performance contact materials such as silver alloys and copper alloys. These materials not only have excellent conductivity and corrosion resistance, but also can withstand higher current shocks and arc erosion, thereby extending the service life of the relay.

Contact load capacity, contact form and number of groups, and contact material selection are important factors that cannot be ignored in the selection process of automotive relays. Only by comprehensively considering these factors can the stable and reliable operation of relays in automotive circuits be ensured, thereby ensuring the overall performance and safety of the vehicle.