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Discussion Starter #1
So, this old bell I found in a old school has a issue. Or its just me, I wired it up simple and when I switch it on the bells hammer hits the shell once. Once per electrical signal... Confusing... Could I have some help? I want it to ring repeatedly like it would in a fire situation.

V24- 60
OHMS 16
6 Amps
14 watts


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It's operating properly. In old systems the pull stations were wound like clocks and would close and open the circuit depending on its unique address code. So "ding ding... ding ding ding... ding ding" meant that station 232 was pulled.
 

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Discussion Starter #3
It's operating properly. In old systems the pull stations were wound like clocks and would close and open the circuit depending on its unique address code. So "ding ding... ding ding ding... ding ding" meant that station 232 was pulled.
What should I do so it rings repeatedly?

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I wonder if 'V24- 60' means 24VAC @ 60Hz, in other words intended to run through a 24V doorbell transformer?

Now, on 24VAC it might still ring only once if that it what it is intended to do.

On a bell that rings continuously, the way they often work is that (1) when voltage is applied, the hammer hits the gong, and breaks a voltage contact causing the voltage to the coil to be lost, then the hammer falls back and remakes the contact, back to (1).

I don't see contacts like that on yours, look for them. If you don't have them it's not going to work.

OR, will 60Hz be going on and off fast enough for the bell to keep up? I doubt it.

You could also use an old radio part called a 'vibrator' to drive it, Mallory made them.
 

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Discussion Starter #6
I wonder if 'V24- 60' means 24VAC @ 60Hz, in other words intended to run through a 24V doorbell transformer?

Now, on 24VAC it might still ring only once if that it what it is intended to do.

On a bell that rings continuously, the way they often work is that (1) when voltage is applied, the hammer hits the gong, and breaks a voltage contact causing the voltage to the coil to be lost, then the hammer falls back and remakes the contact, back to (1).

I don't see contacts like that on yours, look for them. If you don't have them it's not going to work.

OR, will 60Hz be going on and off fast enough for the bell to keep up? I doubt it.

You could also use an old radio part called a 'vibrator' to drive it, Mallory made them.
It was a bell used as a fire alarm at an old school I worked at.



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If you want to try it on AC, you have to pick up a doorbell or furnace transformer at the home center, 120VAC in/24VAC out. You could also research the doorbell in your home to see if there's one there.
 

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You would have to feed an ac or square wave of the appropriate frequency into it.
50Hz is too fast, the hamer could not respond that quickly.
You will have to try lower freqencies probably 1to 10hz or so.
use a simple 555 timer driving a transistor.
 

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Are you sure a DC bell and not an AC bell?
I can't see the label clear enough. Is the model number in it?
Joe is correct. You need 24Vac

Using that battery, you will 'get one ding, one ding only'.....assuming you have the polarity right.

Got to HD and get a 24v door bell transformer.
 

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Even with a 120/24vac transformer you will still only get one 'ding' per switch cycle unless there is a mechanism to rapidly open and close the circuit. The bell itself may or not contain that (as part of an alarm system, that mechanism might have been centrally located). See attached for an 'Interrupter Bell':

https://en.wikipedia.org/wiki/Electric_bell
 

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Many old fire alarm systems used 120VAC on the Initiating Loop (pull stations) as well as on the bells/horns/buzzers. But instead of the bells/horns/buzzers being wired in parallel, as they are today, they were wired in series.

So if you needed 20 bells/horns/buzzers, you divided 120 by 20 and got 6. So you ordered 20 6VAC bells and wired them in series. Some panels had a big
wire-wound variable resistor to provide a voltage drop to help match the load to the source.

For the type bell you have, there was an interrupter in the panel (sometimes motor driven). To make your bell ding repeatedly, take a 24VAC Double Pole Double throw relay and wire one side of the relay's coil through one pole's Normally Closed relay contacts. Wire the bell through the remaining pole's Normally Open relay contacts. When the coil is unpowered, the bell doesn't stroke, but when you apply power:

  1. Power passes through the Normally Closed contacts to the relay coil
  2. The coil pulls in, closing the Normally Open contact causing the bell plunger to stroke BUT ALSO opening the the Normally Closed contact, thus removing power to the relay coil.
  3. Go to No. 1
Your system probably only had 5 bells ( 120 / 24 = 5 ).
 

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Discussion Starter #13
Many old fire alarm systems used 120VAC on the Initiating Loop (pull stations) as well as on the bells/horns/buzzers. But instead of the bells/horns/buzzers being wired in parallel, as they are today, they were wired in series.

So if you needed 20 bells/horns/buzzers, you divided 120 by 20 and got 6. So you ordered 20 6VAC bells and wired them in series. Some panels had a big
wire-wound variable resistor to provide a voltage drop to help match the load to the source.

For the type bell you have, there was an interrupter in the panel (sometimes motor driven). To make your bell ding repeatedly, take a 24VAC Double Pole Double throw relay and wire one side of the relay's coil through one pole's Normally Closed relay contacts. Wire the bell through the remaining pole's Normally Open relay contacts. When the coil is unpowered, the bell doesn't stroke, but when you apply power:

  1. Power passes through the Normally Closed contacts to the relay coil
  2. The coil pulls in, closing the Normally Open contact causing the bell plunger to stroke BUT ALSO opening the the Normally Closed contact, thus removing power to the relay coil.
  3. Go to No. 1
Your system probably only had 5 bells ( 120 / 24 = 5 ).
Alright ill go with it, I'm not a expert tbh. Gunna order this, should I also get that doorbell transformer?

https://www.wolfautomation.com/index.php/catalog/product/view/id/9854/s/ice-cube-relay-24vac-2-pole/?gclid=CjwKCAiA-KzSBRAnEiwAkmQ153KXoLPGLm47YPFEROySee13tM-9SBRBrNM4VUBSjdEu8mCEMklVgBoCKF0QAvD_BwE

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Yes, you will need a 24VAC power source and door bell transformers are generally inexpensive and readily available. To ease wiring, I recommend using a plug-in base for your relay (look to the right of the page in your link). You might also consider putting an On/Off switch in one leg between the transformer and relay.

Here is a quick point-to-point wiring diagram that may help visualize how it works. Wire colors are for clarity only and transformer primary connections not shown. Unmarked relay terminals are the relay's coil.
Relay Chatterbox.png

We used to glue a small relay in a cigar box and call them a chatter box since the relay "chatters".

Good luck with your project!
 
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