A solenoid is an electrical device that is composed of coils of wires and a metal core; when electricity runs through a solenoid, an electromagnetic current is generated. Ideally, a solenoid is an electromagnet. With various designs, solenoids are used in everyday applications. Here are some of the basic facts about solenoids, such as ac laminated solenoids, that hobbyists should know.
How it Works -- When electrical current hits a solenoid, a magnetic field is created because of conversion of electric energy into magnetic energy and vice versa. The electric and magnetic forces come together to cause a solenoid to perform essential functions like shutting and opening valves and electric doors. The principle ensures that a magnetic field is distributed equally throughout the device, allowing it to perform complicated tasks that would require high amounts of energy when completed manually. Solenoids are used in different applications for locking systems, automobiles, gas, and water control.
Loudspeakers -- Electrical energy is transformed into sound inside a speaker because of the electromagnet that is hooked to the speaker cone. Electrical current from an amplifier often changes direction, causing the magnetic field around a solenoid to change too. The changes allow the solenoid to move back and forth, and so does the speaker cone attached to the solenoid. The movement of the cone is what forms sound waves, which you can hear when you plug in your stereo or smartphone.
Circuit Breaker -- When there is an electrical surge that pushes excess current into your home electrical circuit system, a circuit breaker comes in handy to interrupt the current and protect damage of appliances and property. You might have seen a circuit breaker before; however, do you know that at the heart of this device is a solenoid? As current hits a solenoid, the electromagnet creates a pulling force that is directly proportional to the amount of current. When the system detects excess current beyond the handling capacity of the solenoid, a latch mechanism is triggered. The lock prevents excess electrical current from bypassing the circuit breaker. After the high voltage dissipates, the magnetic circuit breaker enables the contacts to close and complete the circuit.
Electrical Doorbell -- The inner workings of a doorbell is complex, yet the device appears simple to an ordinary person. The doorbell is used multiple times a day, but few people know how electromagnetism helps the machine to chime. When a visitor pushes the doorbell button, electrical current travels through the solenoid. However, the current is surplus for a small device like a doorbell, and thus, an internal transformer steps down the current to a practical voltage, often 10-20 volts. The voltage generates an electromagnetic field around the solenoid, which leads to the sound mechanism depending on the type of bell installed such as the buzzer, bell, or chime.