TURNING ON LAMPS (Theory)
Buy our book
Welcome to the home’s electrical systems course organized by NPR Online Technologies!
Before starting the video we recommend that you subscribe to our channel and visit our website .
In this lesson we will see how to turn on light bulbs.
One of the most evident effects of the presence of electricity in our homes is certainly the light produced by the lamps. They transform electricity into light, this is why they are also called electric lamps.
An electric lamp has two electrical contacts indicated in the figure by the the two red arrows.
To turn on the lamp, we must apply an appropriate voltage or potential difference across these two contacts.
The lamps we are considering here operate with 230 Volts, exactly the voltage available across the neutral and hot conductors coming from our electric meter. Here we recall again that 230 Volts is the typical voltage adopted in Europe but in other geographic regions different values are adopted. We already mentioned this aspect in the previous lesson and we recall that any other voltage values do not change the concepts that will be illustrated in this course. It is a simple matter of replacing the 230-Volt value with the voltage value adopted in your country.
Apart from the considerations just made on the voltage value, we have seen that in order to turn on our lamp, we must connect its two contacts to the hot and neutral wires of our electrical system.
As soon as the connection is completed, our lamp lights up, unless there are problems in the electrical system or in the lamp.
So far we have considered a single lamp to turn on. But, what if we have more lamps to turn on simultaneously?
In this case, it is sufficient to continue with the neutral and hot wires up to the second lamp and eventually to the third lamp, and so on.
It can be noted in particular that the neutral and hot wires are directly connected to all lamps.
(Buy our book)
More specifically, this connection scheme is called connection in parallel. In other words, we will say that the lamps are connected in parallel.
The connection in parallel is the only one to be used to power 230 V electric lamps.
It is absolutely not to be confused with the connection in series where the hot and neutral wires are not directly connected to all the lamps. The connection in series is not suitable for our purposes.
However, it is a connection often used for the series of colored light bulbs of the Christmas decorations.
In the connection in series, in fact, the available voltage is divided among the various connected lamps and consequently each lamp is supplied with a voltage lower than the total available voltage.
In our example, the two lamps connected in series would be supplied by 230 Volts divided by the 2 lamps and consequently the voltage across each lamp is equal to 115 Volts. Of course, this value is not appropriate to supply 230-Volt lamps.
In the case of colored light bulbs used for Christmas decorations, this principle is instead exploited.
Each lamp requires a much lower voltage than 230 V, so by connecting dozens of them in series, the 230 V voltage is distributed over them. In this way each light bulb is powered with a much lower voltage that can make it work properly without burning it out.
Well, we have come to the end of this lesson. We have introduced our first circuit able to turn on one or more lamps simultaneously and we have analyzed two typical connection schemes: the connection in series and the connection in parallel which are often used in electrical and electronic circuits.
We suggest you immediately consolidate the concepts you have just learned by carefully reviewing the video of this lesson and above all by going through all our other videos on the subject, by accessing our playlists.
We remind you that our npronline dot tech website is active with numerous insights on these issues.
We also suggest some useful actions that will undoubtedly contribute to the growth of this channel: in particular, we invite you to send us your comments, to like this video and share it with your friends.
Finally, don’t forget to subscribe to our channel to stay up to date on all our activities.
Thanks for your attention and … see you next time!
Buy our book:
