Transformer

Transformer pptx, type ,uses, working, construction

1. transformer

2. Introdution Principle Contruction Types Uses

3. transformer Transformer is a device used for changing low alteration voltage at high current. It changes the alteration voltage without the loss of energy

4. principle It works on the principle of electromagnetic mutual ELECTROMAGNETIC MUTUAL INDUCTION- When the current is provided to the primary winding it behaves as electromagnet due to this, the EMF induced in the area having magnetic field lines to primary winding. V s = N s .d ɸ /dt V s = secondary winding voltage N s = secondary winding turns

5. construction Laminated core – Core are designed not to have current in it. But still there is a leakages current or the eddy current in it to minimize these current the cores are laminated. Winding – Made up of copper or aluminum coated with very thin layer of insulation. Tank – The main function of conserstor tank of transformer is to provide adequate space for expansion of oil inside the transformer. It is usually cylindrical or cubicl

6. ISOLATION – It is provided by using synthetic oil between core and tank. BREATHER – When the temperature changes occurs in transformer insulation oil, the oil expands or contracts and there an exchange of air also occurs when transformer is fully loaded. When transformer gets cooled the oil level goes down and air gets absorbed within.

7. Types of transformer The transformer are divided into three types- a. Static transformer b. Variable transformer c. Auto transformer

8. 1. static transformer The static transformer is based on the principle of electromagnetic induction and is used to alter voltage of an alternating current and to render the current Earth free. Construction – It consist of two coils of insulated wire, the primary and the secondary coils, wound on a laminated soft iron core, the iron coil are completely insulated from each other and one usually contains more turns of wire than the other. The frame is often rectangular in the shape and the coils may be wound on opposite bars of the frame or one on top of the other on a central bar.

9. Working of the static transformer An alternating current is passed through the primary coil and sets up a varying magnetic field which cuts the secondary coil and induced on EMF in it is essential that the primary varies in intensity otherwise there is no movement of the magnetic field relative to the conductor and no EMF is induced in the secondary coil. There is no electrical conduction between the primary and the secondary coils, the energy being transmitted from one to the other by electromagnetic field and is made of soft iron as thin material is easily magnetized and demagnetized. It is laminated to prevent eddy current.

10. Types of static transformer Step-up transformer Step-down transformer Even ratio transformer

11. Step-up transformer If the number of turns in the secondary are more than that the as the primary, the voltage developed in the secondary will be increased or stepped up such a device is called as step-up transformer.

12. step-down transformer If the secondary coil has fewer turns than the primary then the EMF or voltage in the secondary will be less than in the primary.

13. Even ratio transformer If the number of turns in the primary and secondary coils is the same as that of the secondary such as the device is called even ratio transformer.

14. Variable transformer It consist of primary and secondary coil, but is constructed so that one of them can be altered in length. The primary coil has a number of tapings taken from it and a movable contact can be made on any one of these by turning a knob the effect of decreasing the number of turns in the primary coil relative to the secondary is to cause a step-up voltage in the secondary coil. In this way a very crude control of voltage is obtained.

15. Auto transformer An auto transformer consist of a single coil of wire found contact points coming from it can be used as a step-up or step-down transformer. When used as the step-up, CD is the primary coil and AB is the secondary coil. When the step-down, AB is the primary and CD is the secondary coil. Although the autotransformers works on the disadvantage that, it allows only a small step-up and does not render the current Earth free. It is used in the starter circuit of ultraviolet lamp to strike the arc in the lamp.

16. uses In most cases appliances are manufactured to work under some specific voltage. Transformer are used to adjust the voltage to a proper level. The transformer are the basic components for the transmission of electricity. Transformer is used to increase the voltage at the power generating station (step-up) and used to decrease the voltage (step-down) for house hold purpose By increasing the voltage the loss of electricity in the transmission purpose is minimized.

17. Thank you