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Handholding request

onemotoronoe

Sep 3, 2020
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Hi there

I've recently acquired an old doorbell (>40 years) and would like to fit it at home. It was previously wired into the mains and consists of two brass chimes which are each struck in turn by a small hammer when the bell push is pressed. The hammer is controlled by a small electromagnet.

Could anyone offer any thoughts/expertise on how I might be able to install this at home without wiring it into the mains? I'm reasonably capable but know next to nothing about this sort of thing so please be gentle!
 

Bluejets

Oct 5, 2014
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More likely poweted via a 12v transformer.
Any brand name...?
Freidland for example....
post a photo and it may be recognisable...
 

onemotoronoe

Sep 3, 2020
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Thanks for the reply. Yes, it is a Friedland 12v transformer. I've attached a pic of the transformer and the mechanism for info.
 

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bertus

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Nov 8, 2019
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Hello,

Under the tape there should be cover.
The low voltage side shows 3 scews under that cover:

friedland-c75 open.jpg

On the cover the voltages are given:

Friedland C75 Low voltage side.jpg

You need to find out if the chime is working on 8 or 12 Volts.

Bertus
 

onemotoronoe

Sep 3, 2020
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All I know is that two wires exited the low voltage side of the transformer. My guess based on some basic Googling is that the configuration was as in the photo above - wires exiting the 4v & 8v and no earth wire.
 

onemotoronoe

Sep 3, 2020
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I found this image of the installation guide for the same transformer...seems to support the 12v idea?
 

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Bluejets

Oct 5, 2014
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You could select either depending on the run length or the loudness of the chime.
12v should be ok.
Solenoid pulses one way when the button is pressed for the "ding" and springs back under no power for the "dong".
So in most instances, power is only applied for perhaps less than a second.
Note that in place of the tiny wheatgrain bulb they used to use inside the press button, a diode, resistor and small led could be used.
Powers itself through the solenoid and is brdged out when the button is pressed.
 

onemotoronoe

Sep 3, 2020
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Really appreciate your help so far.

So here's the point at which my ignorance is really in evidence. Would you mind just giving a brief description of how you might approach installing this without wiring the apparatus into the mains electricity?
Would there be a way to:
1. Power the solenoid within the chime mechanism using a battery and removing the need for the transformer?
If (1) is not possible/too complicated could the solenoid be powered from a socket and what would I need to do that safely?
2. Send a signal from the bell push to the solenoid without wiring the two together. Your previous reply explains that in a wired solution the bell push is powered by the solenoid but in a potential wireless solution I assume the bell push would require a discrete power source?
If (2) is not possible/too complicated I wouldn't be against the idea of wiring the chime and bell push together but I'd really prefer not to have to wire the whole lot into the consumer unit as it will mean running cable around the house.
 
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