Running DC bell off AC transformer

[Martin Pentreath]

Further to my earlier attempts to sort out a doorbell for my garden, I've done some more research and found the following bells suitable for outside use:

product number 250-384 OR product number 228-6149

The only problem is my existing bell circuit is an AC one (running off one of these:

) and these bells are DC.

I did physics at A level (honest) but it was about 20 years ago, and I can't remember a damn thing about it. Is there reasonably straighforward way of running these bells off the AC circuit, ie some gizmo to convert AC to DC? I guess I could set up a separate circuit with a relay, but I'd rather not.

(PS For the sake of the neighbours, I am intending to include a switch so that it's only on when we're in the garden ;-)

[Rob Morley]

This might refresh your memory :-)

[Martin Pentreath]

Rob Morley wrote in news: [e-mail]:

terribly sensitive pieces of equipment, so could I just get away with a rectifier? I wonder if sticking one of these in the bell wire leading to it would do the trick:

[mike ring]

Rob Morley wrote in news: [e-mail]:

While you're ordering your bell from radiospares, get a bridge rectifier

link may wrap, and will probably expire anyway, if so, find your own link!

There are so many to choose from I can't be more specific, get one with enough grunt to be bulletproof and convenient for you to wire.

It's quick and dirty, and shouldn't need any more components

mike

[Dave Plowman (News)]

If it is a *bell*, a DC one will run ok off AC, but not the other way round. A DC bell has points to interrupt the current to make the 'clapper' oscillate, whereas an AC one just uses the fluctuating voltage that is a sine wave.

Some other types of door 'sounders' might need DC, though, especially electronic types designed to run off batteries only.

AC is easily rectified to DC.

[Peter Ramm]

I spent considerable time reading the various articles here rather than cracking on with my new CU ;-)

Excellent.

[Rob Morley]

Sorry - I would have cut&pasted but there were pretty pictures :-)

[The Natural Philosopher]

[Dave Plowman (News)]

Try reading my previous post. A standard underdome front door bell designated AC only *will not* work on DC. It relies on the alternating waveform to make the clapper vibrate. DC types use contacts operated by the clapper to interrupt the current and allow the clapper to return under spring pressure.

A DC bell might well be ok with AC - there were universal types on sale.