Transformer Basics: What is a Transformer

To better understand how transformers are used, lets first talk about a rule we know to be true in regards to energy. We know that energy can neither be created or destroyed, but it can change or altered. Which is what we are doing when we use a transformer.
Let’s use an example or water. We can have a small stream of water being shot an incredibly high pressure which requries a certain amount of energy. We can also have a large stream releasing the same amount of water, but at a much slower rate. Both of these examples consume the same amount of energy. Both move the same amount of water, but in different ways.
Transformers work in much the same way. They take one type of voltage and convert it to a different kind of voltage. They amount of energy being used however stays the same. So when voltage is increased or decreased by a transformer, we are not increasing or decreasing the amount of energy, we are sampling changing the way we use the energy. we know that the current will change proportionally to the voltage changes becasue of Ohms law. (V=IR) to when we increase voltage, amperage decrease. When voltage is decreased, amperage increases.
So why do we need to change the amount of voltage in things?
Lets talk about something we are all familiar with, the power lines we see everyday.
Most power lines that we see are energized with 10’s of thousands of volts. Why?
Because of Ohms law, we know that the higher the voltage we have, the lower the current.
The amount of current running through a wire will determine the size of wire that is required.
So if we have a low voltage, our wire would have to be very large to accomadate the amount of current flowing through that wire. This can be every expensive and impractical.
So because of this, we normally see power lines running a very high voltages to reduce the size of wire that is needed.
BUT, because power lines are running at such high voltage, it can be very dangerous and cause a hazard to anyone in the area.
In order to make it more safe we need to change the voltage to a lower level to make it safer and more usable in our homes.
This is where a transformer in helpful.
A transformer can take any type of AC voltage and change that voltage. Either up or down. So in the case of our homes. Power companies use transformers to change the voltage from a very high, dangerous voltage down to something we can use safely in our homes.
In industrial applications, it is common to see transformers used to step down voltage from say 480VAC, to 120VAC, to be used in control circuits.
Another common application is your sprinkling system. The vales that operate your sprinkling systems common run on 24VAC, in order to power these valves, we use a transformer to step that voltage down.
There are also scenarios where we might want to increase the voltage, and transformer can do this as well.
So how do they work
Transformers take advantage of a principle known as “electromagnetic induction”
It uses a few different components to accomplish this
There is a primary winding that a certain voltage is applied to. This energized coil creates an electromagnet. Which in turn creates an EMF. (electromagnetic field).
There is then a secondary winding connected to the primary winding through and iron core.
When voltage is applied to the primary winding, it will energize the windings creating an electromagnet. Which in turn creates an EMF. (electromagnetic field).
The EMF created by the primary winding acts on the secondary winding creating a certain voltage we can use.
The number of windings on the secondary in comparison to the primary will dictate the output voltage we receive from the transformer
So if the secondary winding has half the coils as the primary, we will receive half of the voltage.
Or if the secondary winding has double the amount of windings as the primary, then we would receive twice the voltage.
It is common for most transformer to allow from multiple options for input and output voltages.
This is accomplished by tapping into the primary and secondary windings at different spots on the transformer.
Keep in mind… When using a transformer, there is no impact on the frequency level. Just voltage and current.
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[@valentinabalzarotti54]

Ohm's first law says that amperage and voltage have direct proportionality, which does not explain change in the transformer, where the opposite happens. I think at 1:35 you should use the energy conservation law, VI=constant, as you said before. You did a great job, I use your videos with my students. Many thanks

[@DavidGomez-wu2rl]

Excellent explanation 👍👍👏👏

[@RSPSupply]

Thank you David for watching. We appreciate your feedback