Light switches like this are very common yours may look different
depending on which country you are in but basically there are only three
different types of switches particularly in the UK. The first switch that we're
going to look at is a one gang one way. These are all one gang switches.
The gang is the number of switches on the back plate. So if you have one of
those with two switches that would be a two gang. But all of these switches that I have
here are all single gang switches. This is the most basic type of light switch this
is a one gang one way. So in there there's a contact when you flip the
switch it makes the contact and completes the circuit. On the back you
simply have a com terminal and an L1 terminal. When you flick the switch it
breaks the contact when you flick the switch again it makes the contact which
completes the circuit switching the light on. So that is the most basic switch
you can get. A lot of places don't stock these now they will stock the 2 way switch
instead which can still be used for a one way light.
We now come on to the single gang two way switch again it's got contacts
inside there we've got a com, L1 and L2. I have done a video on how to wire a 2 way lighting circuit
and that should help you how to fully understand it and
I've also done a video on how to wire a three-way lighting circuit which should
also help. So this can be used on a two way lighting system by using the com
L1 and L2 terminals. If you just want to use it as a one way switch you simply
put one of the wires into com and it doesn't really matter which other
terminal you put it in. You can either put it in L2 or L1 it will still work.
So that is a one gang two way switch which will be used on either a one way
switching circuits or a two way switching circuit.
A 2 way switch doesn't really have an on or an off position it is either in the L1 position or the L2
position depending on where the switch is. This is also a one gang two way
switch but that is slightly different in that the com is at the bottom on
this switch. So the com is there and then you have got the L1 and L2 although they are marked up
slightly differently on this switch. The most versatile of all of the switches is
the intermediate switch. This is a very versatile switch this can be used for one
way switching, 2 way switching, 3 way switching or even more than 3 way switching.
This is a very clever switch. At the top
there we've got L1 L1 and at the bottom have got L2 L2. If you want to wire this up for a
one-way system choose any of the top terminals and any of the bottom and that
will give you your on/off switch on a single circuit. You can also wire this up on
a two-way circuit by using one of the top terminals as the com and the two
bottom terminals one as L1 and one as L2. Or you can do it the other way around
you can choose the top as L1 and L2 and either of the bottom ones as com.
That way you can use that on a two-way lighting circuit. Obviously on a 3-way
lighting circuit you will be using all four terminals. That just goes to show how
versatile this switch is. You can simply use it for one way switching, 2 way switching
or three way switching or even more than three way switching if
you want. If you've ever wondered what's in the back of there there's nothing
remarkable in there it's simply some little contacts that open or close the circuits.
We will just take a look inside of this one which is the 2 way one.
So if we take a look in there you can see that is the com terminal and then we've
got the L1 and L2 and what happens when you press the switch is it moves that
tiny little contact there and that contact either moves between that
terminal there or that terminal there which alters the circuit. So it's either in
L1 or in L22 depending on where the switch is. So like I said there's not a
lot to look at inside of an actual switch it's simply a couple of terminals
with a contact in between which is moved by the switch when you flick the switch.
I hope this video has been useful in explaining how light switches work. If
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