LED dimly lit, or glowing, even when switched off demo (remastered)


Hi this is a video on a strange
aberration which you can find sometimes with LEDs. This is an LED 8 watt BonLux
dimmable LED. It is unusual in the sense that it doesn’t have any sort of
circuitry there or least that I can see inside it such as smoothing cap or
resistor network with various things that you often do see in LEDs and you’ll
notice that even in the off position it’s lit, dimly but still lit. Now I’ll
switch on just so you can see what it’s like when it’s switched on the
strobing that you see is because the light itself does actually strobe
and if we switch it back you can see that again it’s dimly lit. Now if I show
you against another 8 watt LED which is the MiniSun this is a non-dimmable you can see in the off position it’s not lit at all.
In the on position it’s again it’s 8 watt LED there’s no strobing at all
on this I quite like these and I recommend them
but anyway the reason what I wanted to show this is because of this particular
aberration which is caused by the configuration of the lighting. Now let me
put the stuff into the off and we’ll just take a look at the ceiling rose itself.
Now this is the ceiling rose and this is a typical British ceiling rose what it
looks like but it’s been wire strangely and the reason for that is because this
is normally configured for switched live. So live is switched and the bulb is
permanently connected to the neutral side of things as the normal configuration
that you expect in the UK . Now what I’ve done is I changed that set up because I
wanted to have a switch neutral, sometimes you get this strange
effect and essentially what it’s like is if you have an electrician screwdriver
such as this and I was to put that onto the live, you can see that LED that’s not
an LED it’s a neon and it’s lighting when I touch the back of it and that’s
because the live wire is capacitively couple through the the electrician’s screwdriver and it’s essentially radiating energy from me from my body
and that’s why it’s lit. Now in this particular case you can see that the the
live wire here which is on the brown is connected to the pendant itself. What we
have here is the the live wire is actually going into the pendant so it’s
permanently connected to one side of the LED and the other side is going through
this red wire here, which is one side of the switch it’s coming back through the
black wire which is the other side of the switch and it’s looped in this
particular orange wire into the neutral. So effectively what’s happening is it’s
switching the neutral, so that the neutral is going to the switch and it’s
being switched at that point. So essentially we have the live connected
to this but in the off position the energy essentially would mean that the
whole neutral side this blue wire up and to the point where it reaches the break
in the switch itself will go live and that, a bit like the electrician’s
screwdriver, is like me touching the end of it and it’s radiating and it’s
radiating within the actual switch conduits network itself and that is
allowing just enough energy to actually light a bulb. Now if I had an ordinary
light bulb in there the because the tungsten requires so much more energy to
show any sort of lighting basically you’d see nothing and in this particular
case where you have a network here, which builds a bit of a barrier for the
electricity as such which is allowing it to glow and also there’s a capacitor in
there which I believe is acting like a shunt like a bypass. So it’s never given
to the point where it has enough voltage to actually light it even dimly. I’ll
take that out now what I want to show is, when I change
this so it’s then going to switched live that you will see a difference so let me
just put this on pause…. and we’re back so now I’ve changed it. So it’s going from
the neutral line is connected to one side of the bulb. The other side is going to
the black wire, which is one side of the switch. The other side of the switch
which is coming back, is a red wire and just a little bit more of a close-up of
that so you can see how it’s changed. So the brown wire goes from this goes into
the black wire, which is the switch, comes back to the blue which is the permanent
connection to the mains neutral the other side, is the red wire which goes
through this orange loop into the mains which is the brown wire here on that
side there. So essentially this is what’s called a switched live and in this
particular case, which I had earlier which was glowing, and as you can see in
the off position, it is no longer glowing. So you can see the bulb is no longer glowing
so that’s switched on as you can see it’s strobing like it was before and
switched off nothing, whilst before it was glowing and this is the mini Sun
again I switch that on you can see that it’s actually normally they’re both
acting exactly the same way and the way I would expect it to have so hopefully
this shows the aberration and explains the aberration. Thank you very much for
watching and until next time

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