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Uses of Transformers range from conventional power circuits, doorbells, and toy electric trains to electric generators, etc. Transformer is an electrical device used to “step up” or “step down” the voltage levels between circuits. The use of transformers is to transfer current between circuits without any physical contact between them and without changing the frequency or phase. Transformers work on the principle of electromagnetic induction and mutual induction.
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Key Terms: Power Transformers, Alternating Current, Circuits, Generators, Voltage, Transformers, Electromagnetic induction, Current, Electrolysis, Electroplating
Uses of Transformers
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The following are some common uses of transformers:
- In chemical engineering processes like electrolysis and electroplating, a regulated flow of current is required which is supplied through a transformer.
- Transformers are used for battery charging processes as the voltage is to be maintained so that the internal battery components are not damaged.
- Transformers help in providing high currents required for melting and welding of steel and lower currents for cooling during a steel manufacturing cycle.
- A transformer in a circuit breaker can help in starting and stopping the flow of current with the help of a switch, hence protecting from any other damage.
- Transformers are mainly used for controlling the power of alternating current which helps in increasing the efficiency and ultimately lowering electricity bills.
Transformers
The video below explains this:
Transformer Detailed Video Explanation:
Do Check Out:
| Important Concepts Related to this Topic | ||
|---|---|---|
| Transformer Formula | Power transformers | AC Voltage |
Applications of Transformers
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According to different necessities, transformers can be classified into the following:
- Power Transformers: These transformers are huge in size and occupy a lot of space. They are used for high voltage transfer applications i.e. more than 33 KV.
- Distribution Transformers: Transformers used to distribute generated power to distant places are known as distribution transformers. These kind of transformers are used for distributing electricity at a voltage lower than 33 KV in industry or 220-440 V in household areas.
- Measurement Transformers: A transformer which helps in measuring voltage, power, current etc. is called a measurement transformer.
According to different places of use, transformers can be classified into the following:
- Indoor Transformers: The transformers covered with roofs or kept in shelters, especially when meant for industrial purposes, are called indoor transformers.
- Outdoor Transformers: The transformers mainly kept outside and used as a distribution type of transformers are called outdoor transformers.
Types of Transformers
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A major factor that distinguishes the different types of transformers is the change in voltage. An increase in the voltage is known as a “step up” whereas a decrease in the voltage is called a “step down” method. Hence, a transformer that leads to an increase in the voltage between primary and secondary winding is known as a step-up transformer, whereas that of a decreased voltage is known as a step-down transformer.
- Formula of Step up Transformer: VS = NS/NP x VP
- Formula of Step down Transformer: VS = NS/NP x VP
Where, VP denotes main voltage; VS denotes secondary voltage; NP denotes number of primary turns
- NS denotes number of secondary turns
Types of Transformers
Things to Remember
- A transformer is an electrical device used to “step up” or “step down” the voltage levels between circuits.
- There are two types of transformers: Step up and Step down transformers.
- The application of transformers is based on the necessity and place of use.
- Transformers are mainly used for controlling the power of alternating current.
- Transformers also help in the steel manufacturing or chemical engineering processes.
Do Check Out:
| Important Concepts Related to this Topic | ||
|---|---|---|
| AC Generator | Types of Current | Reactance and Impedance |
| Alternating current | Resonance | LC Oscillations |
| Power Factor | Power in AC Circuit | RMS Value of Alternating Current |
Sample Questions
Ques: What is a transformer used for? (2 marks)
Ans: Transformers are used to change the voltage levels between circuits. One of the most important uses of transformers is that it helps in lowering the alternating current voltages at high current or vice-versa.
Ques: Which of the following does not change in a transformer? (1 mark)
1) Current
2) Frequency
3) Voltage
4) None of the above
Ans: 2. Frequency
Ques: A step-up transformer converts a low input voltage into a high output voltage. Does this violate the law of conservation of energy? (2 marks)
Ans: No, the law of conservation of energy is not violated as the increase in voltage is accompanied by the decrease in it. In alternative current, an ideal transformer input equals the output power.
Ques: What is the application of transformers? (2 marks)
Ans: The application of transformers is based on the necessity and place of use. According to necessity the transformers can be classified into power, distribution and measurement transformers whereas indoor and outdoor transformers are classified under place of use.
Ques: A lamp is connected in series with a capacitor. Predict your observation when this combination is connected in turn across (i) ac source as well as (ii) a dc battery. If the capacitor of the capacitance is reduced, what change would you notice in each case? (2 marks)
Ans: (i) When AC source is connected, the capacitive reactance offered by the capacitor is XC = 1/ ωC. The current flows in the circuit and the lamp glows. And on reducing C, XC increases due to which the glow of the bulb reduces.
(ii) When dc is connected, the condenser is charged but no current flows in the circuit for which the lamp does not glow. Even when the capacitance of the capacitor is reduced, no change takes place.
Ques: The primary and secondary windings each have 60 and 100 turns, respectively. Determine the primary voltage by multiplying the secondary voltage by 250 V. (3 marks)
Ans: Given:
Np = 60, Ns = 100, Vs = 250V
The formula for the transformer is as follows:
Vp / Vs = Np / Ns
Vp = Np / Ns ×Vs
= 60 / 100 x 250
Vp = 150 V
Ques: A transformer contains a main and secondary coil with 500 and 5000 loops, respectively. 220 V is the input voltage. What is the voltage of the output? (5 marks)
Ans: We Know,
500 loops in the primary coil (NP).
5000 loops in the secondary coil (Ns).
220 Volt Primary Voltage (VP)
To find: Secondary voltage (VS)
Solution :
Vs / Ns = Vp / Np
Vs / 5000 = 220 / 500
Vs / 5000 = 0.44
Vs = (0.44)(5000)
Vs = 2200 Volt
Ques: What happens if the power factor is not maintained? (2 marks)
Ans: If the power factor is not maintained, the industries will be penalized. When we employ big inductive loads, the non-linear load draws a greater current. Its power factor will be reduced as a result. A piece of equipment is added to the circuit to improve the power factor.
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