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Why are relays used in cars?
Relays are switches controlled by electrical power, like another switch, computer or control module. The purpose of an automotive relay is to automate this power to switch electrical circuits on and off at particular times.
Why are relays still used?
Relays are used wherever it is necessary to control a high power or high voltage circuit with a low power circuit, especially when galvanic isolation is desirable. High-voltage or high-current devices can be controlled with small, low voltage wiring and pilots switches.
Are relays still used?
For reasons such as these, the relay has long been a contender for implementing simple, but safety critical, logic functions in industrial control systems. Even today, the technology is fending off competition from semiconductor based solid state alternatives. Small signal relays may be used to pass very low currents.
Why are relays used in an electric car?
Recently I did some work on my car electric circuits. I see many relays are used in car circuits. These relays are used for simple switching, and I wonder why these circuits are based on relays and not on transistors or other electronic components usable for switching purposes.
Why are relays used in transistor based circuits?
Relays also offer galvanic isolation, which effectively confines faults. Common failures like short circuits usually damage only one relay, whereas in transistor-based circuits several devices along the way would be affected. I bet people still want their car’s motor running even when the air conditioner or a window lifter dies.
Why do we use a relay instead of a switch?
World renowned cardiologist explains how with at home trick. A relay is a fault sensing device it will sense the fault and send signals to the circuit breaker which is automated and will break the circuit. Whereas a switch will ned human interference to break the circuit.
Why are transistor circuits used in a car?
The environment of a car is a harsh place both electrically and thermally and designing transistor circuits to survive it requires a fair bit of extra work. They provide isolation. While the grounds in a car do all eventually come together isolation is still useful to keep control of where exactly returnc currents flow.