Contents
What can be used instead of relays?
A transistor is an electronic device that can work as a switch. It allows control of a large current by a smaller current as does a relay. Unlike a relay, however, a transistor is not mechanical, and can operate much faster than a relay.
Should I use a relay or contactor?
Contactor: It is a device which is used for repeatedly establishing and interrupting an electric circuit under normal conditions. Control Relay is more commonly used in control circuits which are single phase circuits. Contactors are typically built for switching 3-phase load.
What’s the difference between a relay in a contactor?
A contactor joins 2 poles together, without a common circuit between them, while a relay has a common contact that connects to a neutral position. Additionally, contactors are commonly rated for up to 1000V, while relays are usually rated to only 250V.
How are contactors used in a relay circuit?
All About Contactors. The auxiliary contact is often used in a relay logic circuit, or for some other part of the motor control scheme, typically switching 120 Volt AC power instead of the motor voltage. One contactor may have several auxiliary contacts, either normally-open or normally-closed if required.
Is there an alternative to an electromechanical relay?
A solid state relay (SSR) is an alternative, but SSR modules tend to be expensive. For low currents (~1A) there are affordable SSRs, however, this one costs USD 1.38. An SSR for minimum 5A will already cost you three times as much, so there the electromechanical relay is pretty much the cheapest solution.
Is there an alternative to a 5A relay?
This can switch 5A @ 250V AC, but you may have to derate it if your load is reactive (capacitive or inductive). A solid state relay (SSR) is an alternative, but SSR modules tend to be expensive. For low currents (~1A) there are affordable SSRs, however, this one costs USD 1.38.
How is an auxiliary contact used in a contactor?
The auxiliary contact is often used in a relay logic circuit, or for some other part of the motor control scheme, typically switching 120 Volt AC power instead of the motor voltage. One contactor may have several auxiliary contacts, either normally-open or normally-closed, if required.