Is it possible to have "full" and "dim" lightswitches?

[Harry Bloomfield]

I was using pretty cheap (all I could afford in my youth) 'high voltage' diodes in the 60s, so I'm not sure how old you think bernard's 'original install' may have been

Kind Regards, John

Perhaps so, but they were neither cheap nor commonly available back then. Transistor radios were still using germanium.

 

[bernardgreen]

Copper oxide and selenium rectifiers.

 

[JohnW2]

I did that years ( about 16 ) ago and the flicker was terrible.

That's obviously the theoretical risk - but I have to say that when I've done it (in the distant past), I seem to have had acceptable results. Albeit at half the frequency, it is similar to the 100 Hz flicker one ought to get when dimming an incandescent bulb 'in the usual way'.

Kind Regards, John

 

[JohnW2]

Perhaps so, but they were neither cheap nor commonly available back then. Transistor radios were still using germanium.

Copper oxide and selenium rectifiers.

This was very late 60s (possibly very early 70s) - you can see the four ('top hat') diodes (not copper oxide or selenium - I thing silicon 1N540 or similar) of the bridge (with SCR/thyristor below). The second photo, showing the 'reverse', is proof that I was 'in my youth' at the time

Kind Regards, John

 

[Harry Bloomfield]

I was using pretty cheap (all I could afford in my youth) 'high voltage' diodes in the 60s, so I'm not sure how old you think bernard's 'original install' may have been

Kind Regards, John

Only Bernard can answer that..

 

[bernardgreen]

Only Bernard can answer that..

One permanent mains powered install was in 1967 in our living room. Also kept the boring old central pendant lamp for the "old folks".

 

[winston1]

Another problem with using a diode is that you put DC on the mains and you would need to change your RCD to a type A (so Eric tells us).

 

[JohnW2]

Another problem with using a diode is that you put DC on the mains and you would need to change your RCD to a type A (so Eric tells us).

Yes, eric would undoubtedly tell us that!

 

[SimonH2]

I have some coloured LED lights outside which are nominally 2W each - so a string of 40 is "a bit bright" for the size of garden At the moment they run at 55V from a home-made site transformer my late father made using whatever transformer he had lying around. The transformer obviously suited it, and he had a suitable switch in the bits box, so made it switchable between 55V and 110V.
I've just been searching for a transformer to use on a second set I've just put up. It's been hard work finding one with suitable windings for an auto-transformer - eventually I found a 100VA one from Mouser with 115 primary and 60-0-60 secondary which should do the job nicely.
I think I'll have to employ some electronics and relays eventually as I can't find the right switch for what I want to do with it. I want (with this transformer) a selection of off, 60V, 120V, or full mains with the transformer not powered.