Doorbell light 6vac

[garyo]

Merry Christmas all...

I have a wired doorbell that's powered from its own internal 6vac transformer. The push button is 3metres away, connected by 4-pair phone cable that seems to carry/swtch this same 6vac.

The push button has a few translucent bits in the case, so should look good if I could wire in an led or neon. What's the most practical way of doing this? Can I get an off the shelf component (neon?) that I could run straight off the 6vac and then run that separately down a second pair?

Thanks

Gary

 

[ericmark]

The standard system was to wire across bell button contacts as does not use enough current to sound the bell, however it would depend on the bell, the new electronic bells it may not work with. It would go out when bell pushed showing it had rung.

 

[AndyPRK]

illuminated bell pushes have been around for decades

https://www.ebay.co.uk/itm/2-x-Ligh...749716?hash=item25d3d51f54:g:-UEAAOSwc-tY6~Gw

https://www.ebay.co.uk/itm/2-x-Frie...968216?hash=item2836bbc918:g:vvQAAOSwcgNZNuTI


where the bulb is fitted across the switch contacts. This causes humm on old bells though.

SO if you have a spare pair of wires, using an LED and resistor is an excellent way forward.

 

[garyo]

Cheers chaps. I realised that they existed but dont want to land-fill my nice metal/chrome one, so wondered if there's an easier way than a home brew resistor /led pack. If not then I have a box of that kind of junk in the garage so will add it to the list for 2019.

Cheers

 

[AndyPRK]

so with what you said, and use led and resistor to spare cables

if you think the led can be secured it there and shine light in the correct direction

 

[winston1]

Cheers chaps. I realised that they existed but dont want to land-fill my nice metal/chrome one, so wondered if there's an easier way than a home brew resistor /led pack. If not then I have a box of that kind of junk in the garage so will add it to the list for 2019.

Cheers

You need more than a resistor. LEDs run on DC, you have an AC supply. At the minimum you need a diode, better still a bridge rectifier.

 

[AndyPRK]

You won’t notice the flashing.

Do you think the reverse voltage will damage it?

 

[winston1]

Do you think the reverse voltage will damage it?

Quite possibly.

 

[garyo]

Quite possibly.

Is using a neon an option at that voltage over the length of cable?

 

[DetlefSchmitz]

All neons I have encountered need 90V or so to strike.

 

[flameport]

Two LEDs and a resistor, with the LEDs connected in parallel but in opposite directions, so they are alternately illuminated on each half of the AC cycle.
A 680 ohm resistor should do for 6V AC.

 

[AndyPRK]

I don’t think you need 2 leds TBH.

1 will work fine off AC

 

[DetlefSchmitz]

Well, this turns into a load of guessing, etc. Firstly any recent led will be fine lit only half the time, as they are way too bright these days. That means only one is necessary. However you have to factor in that a 6V ac voltage will exceed the typical reverse voltage. So reverse (zener) current will flow. Now this probably won't cause damage to an led if it is sufficiently current limited, but this is not usually something you can work out from the data sheet. I would also expect a way bigger resistor to be more appropriate for a modern led. To play it totally safe a diode would be appropriate, almost any diode would be fine but a 1N9001 would be an easy choice. The resistor would be chosen by experimentation, but 10k would probably be fine as a starting point.

 

[AndyPRK]

2 dim leds won’t make it brighter!

Suddenly an off the shelf bell push seams the way forward if you don’t know your electronics or have time to mess around