How does a basic relay work?
Relays control one electrical circuit by opening and closing contacts in another circuit. When a relay contact is Normally Closed (NC), there is a closed contact when the relay is not energized. In either case, applying electrical current to the contacts will change their state.
What are the basic relay?
A relay is an electromagnetic switch that opens and closes circuits electromechanically or electronically. A relatively small electric current that can turn on or off a much larger electric current operates a relay. Even if the relay contact is normally closed or normally open, they are not energized.
What is a general purpose relay used for?
General purpose relays are mainly used as a control circuit (relay sequence) for control circuits of automated machines used at various production sites, and for various control systems such as lighting, air conditioning, and water treatment of buildings.
How do you create a relay circuit?
Step 2: Relay Switch Circuit Using NPN Transistor So if a large enough positive current is now driven into the Base to saturate the NPN transistor, the current flowing from Base to Emitter (B to E) controls the larger relay coil current flowing through the transistor from the Collector to Emitter.
What is a relay and how does it work?
What is a Relay and How Does it Work? A relay is an electrically operated switch. They commonly use an electromagnet (coil) to operate their internal mechanical switching mechanism (contacts). When a relay contact is open, this will switch power ON for a circuit when the coil is activated.
Which is an example of an open relay?
Example 1. 4 pin (normally open) relay with the switch on the positive side of the control circuit. Example 2. 4 pin (normally open) relay with the switch on the negative side of the control circuit. Note: These circuits have been simplified to illustrate the function of a relay and therefore exclude fuse protection that would be required.
What kind of relays have only one output contact?
Solid-state relays, however, normally have only one output contact. Solid State Relays, like the one pictured above, are capable of switching high voltages up to 600 VACrms. These relays are designed to switch various loads such as heating elements, motors, and transformers.
What kind of power does a machine tool relay use?
The coil will be operated from the 480VAC line voltage, while the operator controls are operated from 120VAC or 24VDC for safety purposes. A machine tool relay, with contacts rated to 600VAC, can be employed to operate the starter coil from the 480V power source used for the motor power.