Wire Two Chime in Parallel

[Dave Plowman (News)]

Except that it's not centre tapped. That gives equal voltages which may well be important for some circuits.

Intermediate tap perhaps?

[BigWallop]

My apologies. You're correct, it is an intermediate tapping. Or an unequal tapping. Or even a combined third set tapped winding.

But either way, it's still tapped somewhere near the middle. :-))

[Dave Plowman (News)]

Absolutely. The terminals are exactly 1" apart both sides.

[Mo Thanku]

Well if I have wired it, so I am getting the full 12v, than it suggest that I should be using transformer which is 2 amp not 1, as increasing the Volts from 8 to 12V is making no dfferance.

Why is becoming so diffcuilt to have a loud bell -)

Thanks All.

[Dave Plowman (News)]

If the transformer is underrated for the job of driving two or more 8 volt bells, upping the voltage to 12 will probably make things worse.

[Andy Wade]

Bell transformers have been like that since errr, forever. Since the

1940s at least. Dunno why, but it's definitely traditional.

[Dave Plowman (News)]

If you look at ancient Radiospares catalogues, this type of transformer was common as a general purpose replacement.

The now common centre tap - or two identical secondaries - is a function of solid state equipment with balanced supply lines, I'd guess.

[thanku11]

Hi All,

The bulb in my push button have died I was thinking of replacing it with 12V

1 amp blinking one. Now I can see quite a few in Maplin but not sure what to buy as it must be very long life one. Many Thanks Happy New Year

[Owain]

wrote | The bulb in my push button have died I was thinking of replacing | it with 12V 1 amp blinking one.

Do you mean a 12V flashing LED?

| Now I can see quite a few in Maplin but not sure what to buy as it | must be very long life one.

The thing is, the lamp in an illuminated push runs in series with the chime solenoid(s), so even if you have 12V at the transformer you don't have 12V across the lamp. The voltage is divided between all the things in series, so you might only need a 3V lamp. The only way to know is measure the voltage across the push terminals with a voltmeter.

Ordinary 'illuminated bell push lamps' should last a reasonable length of time if not run over-voltage. An alternative is luminous paint.

Owain

[Dave Plowman (News)]

If you only had 3 volts at the lamp of a 12 volt supply, the bell would almost certainly ring, since it would be getting 9.

The resistance of the bell is so low - relatively - and the bulb so high that the bell resistance may be ignored in practice.

The bell might take 0.5 - 1 amp, the bulb around 60 mA

Maplin etc do flashing LEDs which will work at bell voltages and take approximately the same current as a tungsten one. But you might have trouble finding a white one.

[Lurch]

On Sun, 09 Jan 2005 20:47:09 +0000 (GMT), "Dave Plowman (News)" strung together this:

And AC too.

[Dave Plowman (News)]

You'll need a diode too.