Looking for pleasant sounding chime or 'bell tone'

Thread Starter

lespaul

Joined Jan 30, 2008
49
I am looking for a pleasant sounding 'bell' tone or chime for a project I am working on. I have tried about a dozen piezo buzzers and annunciators of various flavors and they all sound obnoxious. Need something pleasant...12 volts DC would be great. I have googled, kicked and scratched, but nothing fits the bill. I did rip apart a two-tone annunciator from RS to see if I could make it just 'one' tone, but its an imbedded circuit...one chip does all.

Any ideas??
 

KMoffett

Joined Dec 19, 2007
2,918
I designed a simple chime circuit ~30 years ago to act as an alarm on an intensive care nursing unit. If you place a large electrolytic capacitor across a Sonalert piezo tone sounder, and briefly pulse it, you get a rather pleasant decaying chime tone. This is like the light/key alarm in some cars. Some variations are attached. You can test the sounds with just the Sonalert, a capacitor, and a battery. :)

Ken
 

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Thread Starter

lespaul

Joined Jan 30, 2008
49
Thanx Guys...will look into the UM66 and also some of your circuit designs, Ken. Indeed, the sound I am looking for is a toned down version of your typical shrieking 2khz @ 90db piezo.
 

Thread Starter

lespaul

Joined Jan 30, 2008
49
Thanx CDRIVE, I have one of those ding-dong chimes from RS. I ripped it open to see if I could make it 'ding' and eliminate the 'dong'. Nothing doing...its one chip does all under the hood. Couldn't find specs online for a Kingstate chip.
 

CDRIVE

Joined Jul 1, 2008
2,219
How does it sound if you break the circuit immediately after the first note? If that sounds acceptable you can use a 555 with a pulse width just long enough to produce the first tone.

Have you ever worked with Microcontrollers? The Picaxe 08M (8 pin DIP) is dirt cheap, can output tones and play music.
 

Thread Starter

lespaul

Joined Jan 30, 2008
49
hey CDRIVE....thanx and yes, I can program Pic's, Props and other micro's, but was looking for a cheap and quick fix.
 

Thread Starter

lespaul

Joined Jan 30, 2008
49
Hey CDRIVE, I would love that!! I am always wanting to learn new things. I have read about the Picaxe, but haven't played around with one yet. Mostly pic24's, 30's and just started programming a few Propellers. Love that controller!!

I may just hammer out a simple tone circuit using a 555 and call it art. This way I can also send that audio signal into an input channel on a Yamaha PM5D. Its a long story, but this is all part of the game show set/circuit that Ken helped me with. I will let you all know how it turns out..:D
 

KMoffett

Joined Dec 19, 2007
2,918
Ahhhhh! So, do you have a schematic of what you have so far? I assume that you are only looking for a single pulse tone with decay...like striking a bell.

Ken
 

Thread Starter

lespaul

Joined Jan 30, 2008
49
Hey Ken...probably modify something like the schematic posted here. I could play around with different R/C to get the tone I am looking for. Ideally the UM66 sounds like the way to go, I cannot find any.

On a side note, I built the second 'game show circuit' with the latching PNP/NPN transistors..you know the one. I scaled it up to 24volts because 12V lamps were easier to find. I also added solid state relays to switch higher current LED's mounted in the contestant podiums.

http://www.555-timer-circuits.com/toy-organ.html
 

KMoffett

Joined Dec 19, 2007
2,918
I've never seem anywhere that sells UM66's. I wound up doing my Jeopardy system using the "Original Two-Wire Game Show Timer" configuration because I could parallel or star them anywhere with cheap speaker wire for an infinite (well, not quite) number of contestants. Have you tried the single-tone Sonalert-type buzzer with a parallel capacitor?

Ken
 

Thread Starter

lespaul

Joined Jan 30, 2008
49
Yeah, I get what you mean...I found that 5 to 8 contestants works great at 24volts. I changed the zener out to 18v and re-biased the transistors but the darn thing would not reset...figured out my base to ground resistor was too high (changed from 1K to 150ohm). Anyway, I digress....i did try a few different piezo elements I had, but could not change their output with a capacitor. It had no effect...perhaps my piezo devices have active components that could be the reason.
 

KMoffett

Joined Dec 19, 2007
2,918
....i did try a few different piezo elements I had, but could not change their output with a capacitor. It had no effect...perhaps my piezo devices have active components that could be the reason.
The Sonalert-types have self contained active tone generators that drive the piezo elements. The amplitude of the tone decreases as the capacitor discharges.

Ken
 

Thread Starter

lespaul

Joined Jan 30, 2008
49
Ken, most of the piezo evices I have are from Kingstate...Chinese company...I believe. In any case they didn't have any effect. I do have a place down the road that sells sonalert...will try one.
 

Thread Starter

lespaul

Joined Jan 30, 2008
49
Hey Ken...just re-read yur post. Indeed the amplitude does change as the capacitor discharges through the piezo devices, but the frequency stays the same. Been so busy building the rest of the circuit and contestant boxes that I haven't had time to spend on the 'bell tone'. Not only do I have to build this to be customer proof, but also stagehand proof... will send pictures of the final product.
 

Wendy

Joined Mar 24, 2008
22,698
I haven't posted here because, frankly, I don't have anything to contribute.

The old project boxes this was a stable. A circuit that would almost oscillate, but not quite, and produced a damped resonant waveform instead.

I'm be looking through the old 300 in 1 project schematics myself.
 

Thread Starter

lespaul

Joined Jan 30, 2008
49
Hey Bill, thanx for the support...always nice to have help from yuz guyz. I have an event that loads-in on Thursday with quite an elaborate set and custom graphics so the game-show will be a nice part of the overall program. Push come to shove I can call an audio que for the 'bell tone' and have it sequenced through an 'Instant Replay'. The 'IR' is just a device that stores many mp3 audio files and can be programmed to play a sound at a certain time or que. It's output is balanced audio via XLR.

Now, somewhere down the road...WAY down the road, I can use the serial input on the Instant Replay and trigger different sounds based on the button push from the contestant boxes. All that requires a micro' and programming I/O, etc.... and our sales guys never give me enough time for this kind of stuff. :mad:
 
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