Hello all, I am looking for a relay to do the following.
I have a 12 volt fire bell that i am wiring up to run in our firestation to ding when we have an alarm, i have the radio which will complete contact closure for 5 seconds. but the bell is a single throw, so until you remove power, it remains in the position of dinging i guess thats what you could say. so, i realize 5 seconds isnt very long as it's slightly longer than the minitors beeping(we have a 3 second b tone), but im looking for a relay quick enough to actually remove power and make the bell sound at least twice, hopefully 3 times. anyone with any ideas let me know. thanks
michael
Im looking for a relay
Moderator: Queue Moderator
Re: Im looking for a relay
There are some time delay relays that when triggered stay 'keyed'
until a set time runs out.
until a set time runs out.
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Tom in D.C.
- Posts: 3859
- Joined: Tue Sep 04, 2001 4:00 pm
- What radios do you own?: Progreso soup can with CRT
Re: Im looking for a relay
The bell you now have is called a single-stroke bell and is used in coded fire
signalling systems. What you should have is a 12-volt vibrating bell. With
the correct bell the bell will ring continuously until power is removed and it
does the contact/break/recontact operation internally.
signalling systems. What you should have is a 12-volt vibrating bell. With
the correct bell the bell will ring continuously until power is removed and it
does the contact/break/recontact operation internally.
Tom in D.C.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
Re: Im looking for a relay
Yes, i am fully aware this is for a fire alarm system, i have a vibrating bell 110vac currently and i love it, but in addition to that im wanting to add the single striking bell because of its unique sound and characteristics. I am just looking to see if someone maybe used a relay similar to what i am looking for in the past just to see if they would be willing to reccomend someone or somewhere that i could look for a relay like this.
thanks
mike
thanks
mike
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kc7gr
- Posts: 1031
- Joined: Wed Mar 13, 2002 4:00 pm
- What radios do you own?: Motorola, Icom, Sunair (HF).
Re: Im looking for a relay
Siemens, and other companies, make relays that can be configured for nearly any type of time-delay or slow-pulse operation. I'm using one at home that, with a flip of a few thumbwheel switches, can be set to do a slow-pulse thing for as long as the trigger signal is present.
You could probably use the contact closure from your radio to drive the trigger lead for this second relay, and that would give you the pulsing output you need to, as Goldie Hawn once put it on 'Laugh-In,' "Well, Ring my Chimes!"
If this sounds right, let me know and I'll get you the part number. They're usually available from industrial electrical supply places (Grainger, Graybar, etc.)
Happy tweaking.
You could probably use the contact closure from your radio to drive the trigger lead for this second relay, and that would give you the pulsing output you need to, as Goldie Hawn once put it on 'Laugh-In,' "Well, Ring my Chimes!"
If this sounds right, let me know and I'll get you the part number. They're usually available from industrial electrical supply places (Grainger, Graybar, etc.)
Happy tweaking.
Bruce Lane, KC7GR
"Raf tras spintern. Raf tras spoit."
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Tom in D.C.
- Posts: 3859
- Joined: Tue Sep 04, 2001 4:00 pm
- What radios do you own?: Progreso soup can with CRT
Re: Im looking for a relay
Okay, now that it's clear that you want a single-stroke bell to sound what
you need is a motor-driven code transmitter from a fire alarm control panel.
It's not a relay but rather a motor-drive make/break contact device that in
march time configuration usually sounds at 120 beats per minute. Not too
many systems use this arrangement these days because the pulsing is
usually handled by the alarm device itself (horn, strobe, etc.) but the
SS bell is the one unit that still needs an external transmitter to make it
work correctly. Simplest way to rig one up would be to use a 1 RPM AC
clock motor with a spring contact setup; you probably wouldn't get the
march time pulse but something slower that would work just as well.
you need is a motor-driven code transmitter from a fire alarm control panel.
It's not a relay but rather a motor-drive make/break contact device that in
march time configuration usually sounds at 120 beats per minute. Not too
many systems use this arrangement these days because the pulsing is
usually handled by the alarm device itself (horn, strobe, etc.) but the
SS bell is the one unit that still needs an external transmitter to make it
work correctly. Simplest way to rig one up would be to use a 1 RPM AC
clock motor with a spring contact setup; you probably wouldn't get the
march time pulse but something slower that would work just as well.
Tom in D.C.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
In 1920, the U.S. Post Office Department ruled
that children may not be sent by parcel post.
Re: Im looking for a relay
So, let me make sure I have this straight:
You have a radio that outputs a contact closure for some short duration Tr (roughly 5 seconds).
You have a bell that will ring ONCE each time power is applied.
You wish to have the bell ring many times during the time the radio is signaling.
You could do that with a 555 IC wired as a multivibrator, driving a reasonably hefty power transistor to drive the bell. Set things up so that the reset line is pulled low by a resistor, and the radio's contact closure pulls reset to V+.
If you want to "stretch" the pulse from the radio, use a second 555 (or use a 556 dual timer). Wire the trigger to the radio, use its output to control the bell ringer 555.
Don't forget to put a reverse biased diode across the bell, so that when you turn off the voltage to the bell the induced back EMF won't blow the circuit.
You have a radio that outputs a contact closure for some short duration Tr (roughly 5 seconds).
You have a bell that will ring ONCE each time power is applied.
You wish to have the bell ring many times during the time the radio is signaling.
You could do that with a 555 IC wired as a multivibrator, driving a reasonably hefty power transistor to drive the bell. Set things up so that the reset line is pulled low by a resistor, and the radio's contact closure pulls reset to V+.
If you want to "stretch" the pulse from the radio, use a second 555 (or use a 556 dual timer). Wire the trigger to the radio, use its output to control the bell ringer 555.
Don't forget to put a reverse biased diode across the bell, so that when you turn off the voltage to the bell the induced back EMF won't blow the circuit.
This is my opinion, not Aeroflex's.
I WILL NOT give you proprietary information. I make too much money to jeopardize my job.
I AM NOT the Service department: You want official info, manuals, service info, parts, calibration, etc., contact Aeroflex directly, please.
I WILL NOT give you proprietary information. I make too much money to jeopardize my job.
I AM NOT the Service department: You want official info, manuals, service info, parts, calibration, etc., contact Aeroflex directly, please.
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spareparts
- Batboard $upporter
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Re: Im looking for a relay
What you need is a repeat cycle timer, with independant on/off times.Gocart878 wrote:I'm looking for a relay quick enough to actually remove power and make the bell sound at least twice, hopefully 3 times. anyone with any ideas let me know.
Power On
Close 1 second
Open 1/2 second
Close 1 second
Open 1/2 second
Close 1 second
Power off
Grainger sells a equal on/off version under part #6C758, with an independant timing version under #2A179 http://www.grainger.com