so in this video Gaz we've got some really interesting stuff to look at this is stuff that
i get really excited about because i love lighting so we're going to be considering different types
of light source so the different kinds of lights that we can use as electricians we'll be looking
at filament lighting also known as incandescent lighting we'll be looking at fluorescent lighting
in both its compact form and the tubular form the more traditional form and also
LED lighting which is obviously exciting because that's that's the way of the future
we'll also consider the different types of connection that are available to
electricians and we'll talk uh particularly there's one particular thing we're interested in
with that Gaz what's that interesting for both being an electrician and obviously for the exam
is whether the lamp itself has polarity so we've got to work that out and as we move towards a
level three test inspection course whether that be for AM2 or AM2S there's always going to be a
light fitting that has polarity and it has to be confirmed by the electrician and we'll look at
that as well in this video so obviously this is the entry point for studies regarding lighting
there will be future videos covering things in a lot more depth there'll even be some
mathematical stuff that we've got to do with calculating lighting levels and things like
that so we'll bring the camera in and we'll have a look at what we've got here on the bench
so we've got a number of lamps laid out on the bench here we're going to consider some
different ones so the first one that we're going to look at is this here the tungsten filament lamp
or incandescent lamp this lamp has been around for about 100 years now and it works very simply
inside here there is a tiny filament of wire that wire is made out of a material called tungsten
and when we pass current through that piece of tungsten wire it starts to get very very hot and
eventually it glows white hot and it gives off light now the downside to this particular type
of lamp is that it needs to get hot to work which means that it gives off a lot of heat now this is
very wasteful because as well as giving off some light this lamp also emits a lot of waste heat in
fact they're so inefficient they're more like little heaters that give off some waste light
in order to stop the filament burning out too quickly we enclose this inside this glass bulb
that goes on the outside and that bulb is filled with argon gas which is an inert gas
and will help to stop the filament from reacting with the oxygen in the air and from burning out
too early so over to my glamorous assistant and we'll see the color of that lamp so we
can see there when the electrical current's been passed through the filament itself that it glows
but the downside as Joe just said as we leave it from for a few minutes that this will get very
warm very hot so that energy is therefore wasted so therefore we've evolved onto different types
of lamps and a more efficient lamps that we're looking at nowadays yeah you might find it hard
to come across a filament lamp these days because they're gradually being phased out as time goes on
because of their inefficiency so we have then the cousin to the filament lamp the tungsten filament
lamp we've got here a halogen lamp now you'll notice inside this outer glass bulb here we've got
a smaller lamp inside there and inside that is a filament very similar to the one that we've got
that Gary's unscrewing now and that filament will still glow it will still get hot it will give off
some white light however the difference with this is that inside that little capsule inside there
there is halogen gas and the way that works is that the halogen gas actually helps to kind of
keep recycling uh the filament the tungsten in there and means that that lamp will actually
last for a lot longer which makes it slightly more efficient than its cousin the filament
lamp should we have a look at that one Gaz drop that one in as well see what that looks like
turn that one on so you can see again what how's that behaving guys
yeah so again exactly the same as before we pass an electrical current through an element
and again it will get hot so there will be some wasted energy with this style of lamp
very good so we'll now look at our third type of light source so about uh what sort of 15 years
ago it was a big push was made to try and start reducing the amount of energy that we're using
in different places in the electrical industry so filament lamps were started to be phased out and
this type of lamp was introduced the compact fluorescent lamp now the way this works is
slightly more complicated but basically current passes through this tube which again is filled
with a type of gas and actually will then start to give off a UV light which is invisible to humans
but the inside of the tube is coated with a phosphorescent powder and as the UV light hits
that phosphorescent powder it glows with a nice white light and it gives off uh light that we
can see by so we'll plug that one in these take a while to warm up so in other words when you
you turn them on initially into a room it doesn't seem as if there's a lot of light output and over
a period of a couple of minutes that we actually increase that light output so let's turn this
one on so there we see and we can see when people moved over and there was a fantastic that we were
saving energy but the quality of the light in the room was actually diminished by the fact that we
were obviously saving energy maybe this was around 15 watts and you may have replaced a 60 watt
lamp with that so you've got the energy benefits from it but the light output wasn't as good
yeah i'd agree with everything you've said there Gaz admittedly there's been great strides
with the technology uh over those recent years they warm up quite quicker the light output is
uh nicer uh however it's to do with the frequency of the light output really that makes it sort of a
less pleasant light to to live by rather than to work by an office you know fluorescent lighting
works a treat but in the home it's not ideal now because of that partly because of that the
industry started to drive towards alternative light sources and now we're looking at this
type of light source and this type of light source is one that is really taking over now
as the main source of light for people it's an led light so LED stands for light emitting diode
again there's some very kind of deep seated physics going on here which explains why this
works so we're not going to go into that into too much detail now but basically we pass a current
through these LEDs and they give off a bright white visible light which is it's got a number
of advantages it can be tuned quite nicely to give off the kind of white light very similar to
a filament lamp so it looks quite nice and there's various different ones available just a word of
warning if you're going to use LED lighting always buy quality ones make sure you go for that and if
it's something for in the home often a warm white is better than a cool white because it gives off
a more filament type glow should we have a look at what an action goes yeah we'll do so we've popped
those ones out i've done a video on this so i just showed the actual effect of taking out a compact
fluorescent lamp and replace it with an LED in my daughter's bedroom so let's turn this one on
okay i think between the two you possibly can see that now that's slightly brighter
and also there is another reduction in the wattage output so this is probably around about 4 watts
where this one was around 15 watts this was around 60 watts so you can see how energy is being saved
and also the lamp itself gets only mildly warm there's no massive amount of heat been generated
by this type of lamp yeah i think it's fair to say this one comes with a little word of warning um
if you do have fluorescent lights in your house Gaz do we want to go out and start replacing our
fluorescent lights with LED lights absolutely not this has got a carbon footprint from its
manufacturer so it's been made you've bought it you're using it only when it's expired it's
life's expired should we then look to replace it with an LED otherwise we're just chucking away
at the carbon footprint of this lamp yeah i think that's a that's a fair shot
so for a quick overview of the different styles of lamps that we have in front of us here we're
now going to concentrate on looking at the actual end connecting points so the first lamps that we
possibly looked at were these style here we've got the Edison screw and the small Edison screw using
exactly the same principle so we've got a screwed section here which is connected to one of our
conductors and a center contact which is connected to another one of our conductors Joe do you want
to explain what they're connected to for me please yeah sure so when we look at an Edison screw type
cap as Gary says we've got two points of contact the actual thread and then we've got this point of
contact on the end now it's really important and as you progress through level two and
up to level three you'll understand it's really important that this center contact here is always
connected to the line conductor that's absolutely critical and therefore the outer thread here will
be connected to the neutral and the idea behind that is that when you start screwing this into
a light fitting if your finger slips down and touches this metal part you're touching a
neutral connection rather than a line connection therefore there's a massive risk of electric
shock yeah so the customer is holding on to this part which connected a line conductor
and they will receive an electric shock and then we've got this style here so we've got
it on both the compact fluorescent and the halogen lamp we've got the bayonet cap this time we have
two points of contact on the top and both of them two points of contact and this one here
and this one here exactly the same principle behind it is that they have what we call no
polarity so in other words it doesn't matter which one of these contacts is connected to the
line conductor and which one of these is connected to the neutral conductor and that's the same in
both cases slightly different contact points but again it doesn't matter if this one is the line
conductor and this one is the neutral we say these style of lamps bayonet cap lamps have no polarity
yeah so again this part on the bayonet cap that doesn't connect to anything at all there's no
electrical connection there it's just these two pins and it makes perfect sense this doesn't have
polarity because when you change an electric lamp in your house you just plug it in and twist it
you don't think about getting it in the right way around here you just plug it in however it'll go
absolutely so in summary then we've gone through the original tungsten filament we've looked at the
halogen lamps the compact fluorescent and the more modern now led lamp and we've done a small
discussion on the style of caps in these cases the Edison screw and the bayonet cap we will
develop this on any further videos do you agree john absolutely yeah that was more to think about
yeah i think we'll break down the threat and live fit in we'll look at lux levels etcetera yep so i
think it's time to say it without actually being in sharp we hope this video has been some help