What is Linear Solenoid

What is Linear Solenoid

• A linear solenoid is a module that transform the electric signal into mechanical force that works in a linear path.
• This solenoid comprises windings that wound on the cylindrical tube constructed by iron and windings are also attached with a plunger that can easily move in the loop of the windings.

• This module is usually employed for on and off the doors electrically, in different machines they close and open the valves.
•  When at the core of the solenoid electrical supply is give it produces the magnetic field and this cylindrical core becomes an electromagnet due to this field current also starts to flow through the windings.
• Due to this current windings also behave like an electromagnet that has its own north and south poles.
• The intensity of the field at the windings can be varied by the changing the strength of the current or it can also be done by varying the numbers of turns in windings loop.
• As after current implementation windings are known like an electromagnet so due to flux of this magnet plunger will move toward the central part of the loop, this movement will apply force on the spring connected with the plunger.
• The force on the plunger is depended on the strength of the flux produced by the windings loops.

Rotary Solenoids

• Mostly selonoids are available that shows linear working phenomena but with these solenoids rotating selonoids are also exits that produce circular motion during their working.
• Their motion direction can be clockwise, counterclockwise or both.
• With the invention of these solenoids, the usage of the direct current and stepper motors has been decreased in smaller motion detection schemes.
• These solenoids can rotate at different angle like twenty-five, thirty-five, forty-five, sixty and ninety degrees.
• Rotation is produced in these motors when their terminals are connected with input supply or removed from supply, with the variation in the polarity of supply rotation is also produced.

• The structure of these attenuators is very simple they consist of a core that is manufactured with the steel and conductive windings are wound around it and with the windings shaft is connected.
• These solenoids are mostly used in vending machines (these are such automated machines that provide tickets, cigarettes, beverage, etc), shutter of the camera is also used these attenuators, typewriter, etc.

Solenoid Switching Circuit

• Normally both solenoids that we study above either rotating or linear are used in such circuits where direct current is used but it can also use for such circuitry where alternating current is used.
• For this purpose, rectification is need of the alternating current.
• Such solenoids that used less value of the direct currents can be regulated by the transistor switching circuitry.
• As we discussed earlier that linear solenoid consists of the inductive coil so there is some protection is required to control the back emf effect during its working.
• For this process, Zener diode or less value resistances are used. In given diagram circuit of solenoid is shown.

  

Reduction of Power Loss in Solenoid

• The main drawback of the linear solenoid is copper losses that occur at the windings of the solenoid.
• Due to this power loss occur heating produced at the windings wound on the core of the device.
• With the passage of the time if a solenoid is remain joined with the input supply it will cause to increase the power losses across the windings and increase the temperature.
• To minimize these power losses there are 2 ways first one is the to decrease the current passing through the coil or cut off supply after some interval of time.

• The simplest way to reduce voltage is to increase the value of the voltage at input so current will minimize and copper losses will decrease.
• There is another method that is mostly used is to connect a series resistance with windings of selenoid this structure is shown in a given figure.
• This resistance will control the amount of the current passing through the solenoid by lossing some power across it.

Applications of Linear Solenoid

• These are some applications of seloneiod that are described with detailed. Let's discuss them.
• Due to different features of coil it mostly used in different medical instruments, locking networks, instrumentation, robotics.
• This module also implemented for the on and off valve electrically.
• It used in different security circuits for locking and antilocking of doors.
• In electronic devices like computer, laptops, fuel injectors gears of cars also consists of solenoids.
• The main feature that makes more effective for different circuits is its quick response for electricity.