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Are you talking about linear voltage regulators or switching voltage regulators? I understand that the latter are more efficient but emit much more RF noise. I'm not sure I would want to get audible interference on my AV systems. Is that a real world risk? I guess the other point is that if it...

I have to give you credit for persistence, but MikefromLondon gave some persuasive reasons why this might not be such a great idea. I don't remember seeing any response from you on this...

The stainless steel backplate is designed for attaching directly to the wall, rather than to any form of back box. I will therefore have to drill a hole through to the inside wall, where I intend to fit a recessed junction box to contain all the other components. Four wires are therefore...

I have now obtained those two capacitors, but when I started to work out exactly how I would assemble all the additional electronic components, I realised that I had deluded myself that my Option D wiring diagram would need only two conductors routed to the illuminated pushbutton. Four...

You have reminded me that I have had an ancient Tektronix oscilloscope in my attic since Adam was a boy. It was being disposed of by my employer at the time and I got it for £10, but it has never been used for any practical purpose. Time has probably taken its toll on the capacitors, etc, and I...

I am embarassed to tell you that I already have a degree in electrical engineering. However, I graduated 50 years ago and have never designed an electrical circuit in my life. My training at university was more theoretical than practical and preceded the wide availability of LEDs, which...

BTW, when you say that a capacitor would enable the LED to stay lit for a few seconds while the button is being pushed, do you mean the same capacitor C1 location shown on my wiring diagrams for suppressing any flicker?

It's 6.4v DC across the 1k resistor. Actually, even though I asked for a 1k, it appears to be a 1.1k Ohm resistor (colour code is Brown, Brown, Black, Brown, plus Brown for tolerance). As you say, there is no need for me to light up the entire street with my LED. All I need is something that...

When connected directly to my 8v AC transformer in a test setup, the bridge rectifier delivers 13.6v DC with no load. Connecting that DC source to the LED of my pushbutton via a 1k resistor gives an acceptably bright white light, though I guess it will dim a little when the bridge rectifier is...

I thought you meant your age - and then I clicked the Thanks button... :)

I have now obtained a packet of Vishay W02G-E4/51 bridge rectifiers and a selection of resistors. However, I have just realised that my Wiring Option C requires three conductors to be routed to the pushbutton. I have therefore generated the attached Wiring Option D diagram, which puts the bridge...

It's encouraging to know that I am unlikely to burn my LED to a crisp unless I do something really stupid. I plan to order a bridge rectifier and a 1k Ohm resistor tomorrow and get this show on the road.

As there is an element of doubt on what value of additional series resistor might be required to limit the current through the LED, how about using a trimmer potentiometer such as the following? http://uk.farnell.com/bourns/3296w-1-202lf/trimmer-25-turn-2k/dp/9353232

I'm now tucked up in bed doing the Daily Telegraph cryptic crossword, but I've just made a quick dash for the Thanks button...:):)

There's a bit of a chicken and egg situation here, as I won't be able to measure the real world voltage until I actually connect the circuit. However, I don't want to find out the hard way that a DC voltage of around 23v causes too much current to flow through the LED. It seems safer to...

Capacitor symbols now corrected. However, I'm not sure I know the circuit symbol for solar flares... Would it not be a good idea to start with an additional series resistor to limit the current through the LED?

As it happens, our house is fitted with a Friedland chime. Ding dong, indeed. I have summarised most of the advice provided so far in a set of three wiring options, shown in the attached diagram, and I would very be grateful if you good folks would check it carefully for any mistakes. At...

I almost forgot to thank flameport for highlighting cheap Chinese sources of replacement pushbuttons, should that ever be needed. Some of the photos on that link look suspiciously close to my current pushbutton! It's now looking much less likely that I will be looking for a dedicated 12v DC...

I am now going to lie down in a darkened room to ponder all the great advice I have received via this forum over the past 24 hours. The assistance from everyone here is much appreciated :) Once I have decided what to do, I will let you know the result. David

I just happen to have a 15 year old version of AutoCAD LT that I used to use at work. It still manages to run under Windows 10, with a few quirks, but does all I need for personal purposes. The full fat version of AutoCAD is a 3D program, while AutoCAD LT is 2D only.