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OT - How to Ring My Bell

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  • CPeter
    replied
    It would have been used to ring out a code sent by the fire alarm box. It would ring a certain pattern of rings and spaces and the firemen would look at the chart and know where to go for the fire. The pull stations all had an individual number and a cam that opened and closed the contacts to send the signal. The cam was driven by a clockwork type mechanism powered by a spring that had to be rewound after the box had been "pulled".
    Peter

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  • kev74
    replied
    Originally posted by J Tiers View Post

    The assumption was, from the reference I found (not as informative as PSTP's) that it was intended to ring like a school bell at the end of class times, etc, implying an extended ringing. It seems that is not the case. If it was to ring in that way, the hammer would presumably be intended to vibrate at line frequency, pulling in to ring at each "half-cycle" of AC, pulled back between them by a spring, hence 120 times/sec for 60 Hz.

    As a single ring bell, that does not apply, and gravity would work. Nobody was suggesting to re-engineer it.... well some may have, but that was not my intent.

    What were single ring bells intended for? The link was to fire alarm items, was there a coded ring for the location of the alarm that was pulled?
    My guess is that whatever control mechanism - central clock, fire control, etc. - sent a signal to the bell sent an alternating on-off signal. I was hoping to find such a switching mechanism. I haven't been able to find any info on these though.

    I like the telegraph key idea above though. I think that's what I'll go with.

    I bought this thing on a whim, to fool around with. A telegraph key will make it more fun!

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  • J Tiers
    replied
    Originally posted by kev74 View Post

    The bell is being run on a 12vAC. Should be close enough for a bell.

    The hammer is thrown up when power is applied and falls back via gravity. Everything works as is should. I'm not sure where you got 120 Hz from.

    As stated above, I won't be re-engineering the striker mechanism.

    Thanks for the help.
    The assumption was, from the reference I found (not as informative as PSTP's) that it was intended to ring like a school bell at the end of class times, etc, implying an extended ringing. It seems that is not the case. If it was to ring in that way, the hammer would presumably be intended to vibrate at line frequency, pulling in to ring at each "half-cycle" of AC, pulled back between them by a spring, hence 120 times/sec for 60 Hz.

    As a single ring bell, that does not apply, and gravity would work. Nobody was suggesting to re-engineer it.... well some may have, but that was not my intent.

    What were single ring bells intended for? The link was to fire alarm items, was there a coded ring for the location of the alarm that was pulled?
    Last edited by J Tiers; 02-17-2020, 09:07 PM.

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  • kev74
    replied
    Originally posted by PStechPaul View Post
    You could get a "Vibroplex" telegraph key, which sends a series of pulses when pressed. It may even be a fun project to make:

    https://www.electronics-notes.com/ar...-morse-key.php

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    Buy one for $55 + shipping:

    https://www.ebay.com/itm/VIBROPLEX-T...4AAOSwW1NeQgdf

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    That might be the best idea yet!

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  • PStechPaul
    replied
    You could get a "Vibroplex" telegraph key, which sends a series of pulses when pressed. It may even be a fun project to make:

    https://www.electronics-notes.com/ar...-morse-key.php

    Click image for larger version

Name:	morse-key-vibroplex-mechanical-bug-presentation-1320.jpg
Views:	45
Size:	6.3 KB
ID:	1856035
    Buy one for $55 + shipping:

    https://www.ebay.com/itm/VIBROPLEX-T...4AAOSwW1NeQgdf

    Click image for larger version

Name:	s-l1600.jpg
Views:	38
Size:	239.5 KB
ID:	1856036

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  • kev74
    replied
    Originally posted by J Tiers View Post
    I suspect the biggest problem here is that the bell is maybe being tried on 110 volts.

    Ummmm.... it is intended, apparently, for use on 11 volts, as in "eleven". Higher voltage will probably just jam it, as seems to have happened. Expanding the picture also seems to show the "11" on the dataplate.

    It seems to be a school bell as mentioned here:

    https://www.worthpoint.com/worthoped...ell-1815135562

    If it actually is being powerd by 11VAC, then check to see that the "dinger" is free and not being held back by gunk of some sort that provides friction. It may heve, or be supposed to have, a spring to pull it back, and if that is missing or not effective, it may stick and not "go" at the 120Hz rate that it is supposed to.
    The bell is being run on a 12vAC. Should be close enough for a bell.

    The hammer is thrown up when power is applied and falls back via gravity. Everything works as is should. I'm not sure where you got 120 Hz from.

    As stated above, I won't be re-engineering the striker mechanism.

    Thanks for the help.

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  • J Tiers
    replied
    Ah.... your reference find is better than the one I found.

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  • PStechPaul
    replied
    It is an ASJ10 single stroke bell, circa 1967:

    http://firealarmcollector.com/index....electric-time/

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  • J Tiers
    replied
    I suspect the biggest problem here is that the bell is maybe being tried on 110 volts.

    Ummmm.... it is intended, apparently, for use on 11 volts, as in "eleven". Higher voltage will probably just jam it, as seems to have happened. Expanding the picture also seems to show the "11" on the dataplate.

    It seems to be a school bell as mentioned here:

    https://www.worthpoint.com/worthoped...ell-1815135562

    If it actually is being powerd by 11VAC, then check to see that the "dinger" is free and not being held back by gunk of some sort that provides friction. It may heve, or be supposed to have, a spring to pull it back, and if that is missing or not effective, it may stick and not "go" at the 120Hz rate that it is supposed to.
    Last edited by J Tiers; 02-17-2020, 06:22 PM.

    Leave a comment:


  • danlb
    replied
    As pointed out earlier, wire a simple Normally open "contact switch" that presses against the clapper when the clapper is at rest. When you press the button the solenoid will push the clapper towards the bell and in doing so it will break the circuit. When the clapper falls back to it's resting position it will close the circuit again. It will go back and forth at a rate determined by the speep at which the clapper moves. When you release your button it will stop. Total cost under 3 bucks.

    A similar idea is to wire a small 60 RPM gearhead DC motor to your switch. Put a cam carved to your desired ring pattern on the shaft. The cam would push on a contact switch that is wired in series with the bell. You can have it ring once per revolution or something fancier.

    What the New York Stock exchange uses is a couple of swinging hammers that spin to sound the bell. If they spin slowly you get clang--clang--clang. Fast you get clangclangclang.

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  • darryl
    replied
    The oldest way of doing this is to wire up a relay using one set of contacts to supply power to the relay coil. When you push the button, the continuous power is supplied, but when the one set of contacts opens, the current is interrupted. The relay falls back, the contacts make again and it pulls in again, only to repeat the cycle.

    You can duplicate this action by adding a microswitch to the solenoid that swings the hammer to ring the bell. As the solenoid pulls in, the switch is activated and allows the hammer to fall back to repeat the cycle. Use the Normally Closed contacts on the microswitch, in series with your push button, and experiment with the positioning of the switch to get maximum stroke out of the hammer.

    Back in the day, car radios used this method in something called a vibrator to switch power into a transformer to generate the high voltage needed for the tubes to run. There was no drive circuitry, just the opening and closing contacts of the vibrator to provide the switched frequency.

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  • Paul Alciatore
    replied
    Oh for Pete's sake. You always add a swamping diode (reversed biased) to a coil for that.



    Originally posted by Franz© View Post
    How will solid state handle the spike coming back from the coil of the bell as the flux field collapses?

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  • A.K. Boomer
    replied
    Has to be something more fun than pressing a switch --- something kids would have fun using (kids meaning full grown men of course lol)

    like grandfather clock weights that run a little gearbox with the final high speed gear having little arms with hardened hammers sling out once it gets up to speed and they contact the bell shell...

    gut out the brides old alarm clock and get the drivetrain out of it --- use that - get in trouble for using it, then you can tell everyone about all you had to go through to build your bell system...

    Leave a comment:


  • PStechPaul
    replied
    Connect the coil to line voltage through a telegraph key so you can send messages in Morse code. If you need emergency assistance in the shop, you can send an SOS :

    dingdingding Dong...Dong...Dong dingdingding

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  • A.K. Boomer
    replied
    You can't make it too easy - otherwise it won't be worth "ringing"

    so --- here's what you do - all mechanisms encased in plexiglass to amuse onlookers,,, you turn an Archimedes screw that lifts a series of steel balls to a higher destination above the bell, they sit there waiting to be used, when in the mood you pull a chain attached to a hinged door that releases the balls down a chute aimed directly at the outer parameter part of the bell, they do the ringing and get guided back down into the entrance gate of the pick up of the archimedes screw to start the process all over again,,,
    oh yeah - there's an adjustable flap that slows the balls down out of the exit gate towards the bell separating them further apart, now you have a different ring tone, you can even get fancy and build a series of gate controls with different size steel balls to play a tune,,, there - now you have something to keep you busy the rest of your life lol

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