If you have a little knowledge of electricity, then you have heard about a transformer. This is typically a static device that transfers AC electrical power from one circuit to another at the same frequency. However, the voltage level will be changed in the process. So that is the function of a transformer.
Since the transformer changes the voltage level, it means that it can either reduce it or increase it. The increase or decrease in the voltage transmission is made possible by a step-up and step-down transformer. So, what are the main functions of a step-up and step-down transformer? Without any doubt, you can already take a wild guess, but we will be discussing that further in this article. Let’s get on with it, shall we?
Step Up Transformer
With a step-up transformer, the output/secondary voltage will be greater than the input/primary voltage. Typically, a step-up transformer will decrease the output so that the input and output power are kept equal.
The number of turns in the secondary winding in a step-up transformer is always greater than those in the primary winding. The reason for this is that a high voltage is developed on the secondary side of a transformer.
In other words, the voltage turn ratio of the step-up transformer is 1:2. Plus, the primary winding of the step-up transformer is made up of copper wires that are thick insulated. The thick insulation is to contain the low magnitude current that flows through the transformer.
Where is Step Up Transformers Used?
Step up transformers will mostly be used in the transmission lines to transform the high voltage that is produced by the alternator. In this case, the power loss of the transmission line is directly proportional to the square of the current that flows through the transformer.
For countries that power is generated at around 11kv, a step-up transformer will be used at the generating station. Here, AC power will be transmitted at high voltages of 220v-440v over long distances.
Step-up transformers have less output current, which is why they are used to reduce the loss of power. Plus, these transformers will be used to start an electrical motor in X-rays machines, microwave oven, and more.
Step Down Transformer
A step-down transformer, on the other hand, is one that the output (secondary) voltage is less than the input/primary voltage. Here, the number of turns on the primary of the transformer is more than the turn on the secondary transformer.
The step-down transformer will cut down the output voltages. It will convert the high voltage (low current power) into low voltage (high current power). For instance, if the power circuit carries around 110-230v and a device or gadget in the house need like 16v or so, a step-down transformer will be needed here. In this case, the transformer will bring down the voltage from 110v/220v to 16v.
The voltage turn ratio of a step-down transformer is 2:1. This ratio helps to determine the magnitude of voltage transforms from the primary windings to secondary windings of the step-down transformer.
By the way, a step-down transformer consists of two or more coils that are wound on the iron core of the transformer. The transformer works on the magnetic induction principle between the coils.
If a voltage is applied to the primary of the coil, it will magnetize the iron core. The iron core will then induce the secondary windings of the step-down transformer. Therefore, the voltage will transform from the primary to the secondary winding of the transformer.
Usually, step-down transformers will be used for electrical isolation, to control home appliances, in a power distribution network, and more.
If you need to use a transformer at home for your appliances or gadgets, ensure that you go for the best step down transformer.
What Are the Key Differences between a Step-up and Step-down Transformer?
The output/input voltage
In a step-up transformer, the output/secondary voltage is greater than the input/primary voltage. Conversely, the output voltage will be less than the input voltage in a step-down transformer.
With the step-down transformer, the low voltage winding is the secondary winding, whereas the high voltage is the primary winding. Conversely, the low voltage winding is the primary winding in a step-up transformer.
The current and magnetic field of a step-up transformer is less developed in the secondary winding but highly developed in the primary winding. On the other hand, the current and magnetic field will be high in the step-down field.
For the record, you should know that the current is directly proportional to the magnetic field and voltage is proportional to the current. When the voltage is increased, the current too will increase. But in a transformer, an increase in the voltage will decrease the current. This way, the power will remain equal in both the sending and receiving ends of the transformer.
Copper Wire Insulation
The step-up transformer comes with thick insulated copper wires for the primary winding. On the other hand, the secondary winding will come with thin insulated copper wire. But, a step-down transformer will have a thick insulated copper wire for secondary winding due to the high output current.
In general, the thickness of the wire will depend on the capacity of the current that flows through them.
Can You Use The Same Transformer as a Step-Down and Step-Up?
Yes, one transformer can be used in both situations. In other words, you can use the same transformer as a step-down transformer or a step-up transformer. What matters here is how the transformer is connected to the circuit. Suppose the input supply is given on the low voltage winding, it will be a step-up transformer. But if the input supply is fed on the high voltage winding, it will be a step-down transformer.
Nonetheless, it is advised to go for a specific step-down transformer if you need one. This will assure you of making the correct connections and achieving the voltage output as needed. Make sure that you consider the delivery and durability of the transformer before you buy it. A step-down transformer can be used in multiple applications, and you can be sure of finding it relevant enough. Just make sure you follow the user guide when setting it up.