Lighting puzzle

[JohnW2]

Sorry my old friend. A lamp holder holds the lamp (a.k.a the bulb) but bulb is actually a wrong term), the lamp is, traditionally, a bulbous shape though, I will give you that one .

Maybe - but, as I always say, that means that I now have to insert a lamp into my lamps (standard lamp, desk lamp, inspection lamp or whatever) - which feels at least a little odd

... another wrong term is "Plastic", any material having plasticity my be referred to as plastic but it may be metal or something else though.

I think there is confusion about the meaning of "plastic" when used as an adjective and its meaning when used as a noun.

In terms of adjectives, as you imply many/most metals are either 'plastic' or 'elastic' (adjectives), and only rarely brittle - and I think that even glass exhibits some plasticity. However, when used as a noun it has the meaning that 'everyone knows', and which corresponds to the definition of the word (as a noun) in most dictionaries.

The corollary of what you said is that some 'plastics' (noun) are not significantly (if at all) 'plastic' (adjective) - just try 'bending' one of the white electrical accessories made out of urea-formaldehyde resins In fact, I think/suspect that most/all thermosetting plastics (noun) are not actually significantly 'plastic' (adjective).

Kind Regards, John

 

[ebee]

John, you have put it far more eloquently than I could have done

 

[JohnW2]

John, you have put it far more eloquently than I could have done

Well, I've just explained the facts, so I'm not too sure about 'eloquence'

My A-Level Chemistry teacher did not understand this difference between the noun and the adjective I remember him spending nearly a whole lesson quizzing us about the definition of 'a plastic'. We offered all the sort of suggestions you might expect - "polymer", "synthetic material", "man-made material", "electrically non-conductive material" etc. etc., all of which he said were 'wrong'. It eventually transpired that what he was wanting us to say that they 'were plastic'. However, as we both know, not all plastics are plastic (and a lot of non-plastic materials are plastic)!

He seemed to like that sort of game. I remember him doing the same with the definition of 'a flame', but on that occasion I think most of us learned something - most of us offered suggestions relating to it being exothermic are 'light-producing' etc., but I think what most of us had missed is that it is an exothermic reaction between two gases (substances in their gaseous phase).

 

[SUNRAY]

Hi Sunray, I think some of us might be a bit averse to running those singles from many points/places around the house on the thought that it might confuse others (or even ourselves at a later point in time say) although it could be said to be slightly irrational as a thought because with lighting circuits we might start on the premise of three basic methods of wiring being "fairly common" and adding another "quite uncommon" method into the mix of things) especially if for more than one circuit. and then we might end up with two circuits in one box which we usually try to avoid)

The SCR one as a simple concept seemed OK but then again (the trigger wire was in bog standard alarm flex cable) unexpected voltages in poorly insulated conductors for one thing and the "how many circuits" converging in one place without warning questions too.

I have done a very few switch arrangements with, example, switching 5 Lamps/Bulbs/Luminaire1 for each of the 5 and then the 6th to overide all 5 into the "illuminate all five" position. Suitably labelled at the switch and the consumer unit and with a suitable diagram at the consumer unit.

Whatr's the point of the bridge rectifier?

 

[ebee]

Whatr's the point of the bridge rectifier?

With a bridge rectifier in the rose etc then it would ensure that the flex and lampholder would only supply L & N ir order if wired such and reversal of polarity would be ruled out. Potentially a bit safer, particularly with ES lampholders old and new?

Actually your question made me take a look again, no it wouldn`t would it? it would only ensure +ve and -ve whether derived from the L or the N.
Well spotted that man - I stand corrected.
That`ll teach me to be a smart Alec!

Therefore the solution would be a relay , which is not allowed by the OP!

 

[JohnW2]

With a bridge rectifier in the rose etc then it would ensure that the flex and lampholder would only supply L & N ir order if wired such and reversal of polarity would be ruled out. Potentially a bit safer, particularly with ES lampholders old and new?

I've very confused, perhaps because I'm missing something (quite likely!) ....

Are we not talking about AC? If so, then feeding the lampholder via a bridge rectifier will result in it receiving 'raw DC' (alternate sine waves inverted). So, one of the poles of the lampholder will always receive the 'positive' of that DC, and the other the negative. However, at any point in time, one of the poles will be 'connected' to either the L or N of the AC supply, that switching between L and N every half cycle, won't it?

Edit: when did your edit appear - did you slip it in whilst I was typing? (I certainly hadn't previously noticed it!) Anyway, we seem agreed that a bridge rectifier would not achieve what you initially suggested!

Kind Regards, John

 

[ebee]

I did it eariler this morning John , after I read Sunray`s comment then thought - by jove he is correct! so I put my initial comment of 7:29 post 65 then covered it a bit later by altering post 64 so as to leave evidence of my shameful error once I`d had a brew and a bite and learned how to cut and paste those bits properly etc.

 

[ebee]

I am quite prepared to repent for my sins if anyone requires it.

I had a Senior moment thinking streaming the pulsing half waves as plus and minus would also align L with L and N with N.
Never mind I know an Electrician (at least 12 months older than me and time served) who always refers to L & N as pos and neg!

I could have launched the Captain Mainwaring Defence - "Hah Good! I was wondering which one of you would notice that one!" but I know you would all see through my ploy.

 

[JohnW2]

I did it eariler this morning John , after I read Sunray`s comment then thought - by jove he is correct! so I put my initial comment of 7:29 post 65 then covered it a bit later by altering post 64 so as to leave evidence of my shameful error once I`d had a brew and a bite and learned how to cut and paste those bits properly etc.

Well, whatever the chronology, I certainly hadn't 'noticed' your edit before I wrote and posted mine (which said exactly the same as your edit) - so maybe I'm to blame for 'inattention'

 

[JohnW2]

I am quite prepared to repent for my sins if anyone requires it. ... I had a Senior moment thinking streaming the pulsing half waves as plus and minus would also align L with L and N with N. Never mind I know an Electrician (at least 12 months older than me and time served) who always refers to L & N as pos and neg!

Fret ye not - we've all been there, and sometimes in far 'worse' ways

Kind Regards, John

 

[SUNRAY]

Fret ye not - we've all been there, and sometimes in far 'worse' ways

Kind Regards, John

Ohhhhh. Yessssss

 

[SUNRAY]

The other option could be a transformer.

 

[morqthana]

How can I also control it from the right end of the room?

With an arrangement of levers, strings, and pulleys from one end of the room to the other.

 

[ebee]