Can anybody help?

I am a CPA, in completely over my head, building a prototype keychain
game. In this game, I need to use two audible signals, a chime when
you score a point, a slightly different "unpleasant" chime when you
lose a point.

My device is 35 X 25 X 9 mm; I would like to use a chime like one
found in a wristwatch. It needs to be small, and about that loud.

I have found a piezo buzzer, 5mm, but I'm not sure what they can sound
like. They also seem to draw a lot of power, and are 85-100db, which
sounds loud.

Am I even in the correct forum? What is that part? Where can I get
sample quantities?

Thanks to those who can help me.

George

 

[Active8]

On 12 Mar 2005 20:19:28 -0800, scoremind@gmail.com wrote:

I am a CPA, in completely over my head, building a prototype keychain
game. In this game, I need to use two audible signals, a chime when
you score a point, a slightly different "unpleasant" chime when you
lose a point.

My device is 35 X 25 X 9 mm; I would like to use a chime like one
found in a wristwatch. It needs to be small, and about that loud.

I have found a piezo buzzer, 5mm, but I'm not sure what they can sound
like. They also seem to draw a lot of power, and are 85-100db, which
sounds loud.

It is, but you don't have to drive it that hard.

Am I even in the correct forum? What is that part? Where can I get
sample quantities?

Maybe sci.electronics basics would be better, dunno, and not sure
off hand. If you're that far over your head, what's involved in the
rest of the game? Electronics beyond driving a piezo?

You can check Mouser and Digikey for the part and the sales rep may
be able to arrange samples. I saw a piezo company maybe a year ago,
and if you google enough, you'll find one, and either they or a rep
can arrange for samples. The one I found was in UK, IIRC, so maybe
that's not for you. I just needed some tech info.

There's 2 types, also. Self-oscillating and the one you supply a
tone to. If you try to apply a frequency to the former that is not
the same as the resonant freq, you may get the kind of unpleasant
discordance you're looking for. Maybe not.

Can you give us the specs of the one you've found? The 5mm part.

--
Best Regards,
Mike

 

Active8 wrote:

On 12 Mar 2005 20:19:28 -0800, scoremind@gmail.com wrote:

I am a CPA, in completely over my head, building a prototype
keychain
game. In this game, I need to use two audible signals, a chime
when
you score a point, a slightly different "unpleasant" chime when you
lose a point.

My device is 35 X 25 X 9 mm; I would like to use a chime like one
found in a wristwatch. It needs to be small, and about that loud.

I have found a piezo buzzer, 5mm, but I'm not sure what they can
sound
like. They also seem to draw a lot of power, and are 85-100db,
which
sounds loud.

It is, but you don't have to drive it that hard.

Am I even in the correct forum? What is that part? Where can I
get
sample quantities?

Maybe sci.electronics basics would be better, dunno, and not sure
off hand. If you're that far over your head, what's involved in the
rest of the game? Electronics beyond driving a piezo?

You can check Mouser and Digikey for the part and the sales rep may
be able to arrange samples. I saw a piezo company maybe a year ago,
and if you google enough, you'll find one, and either they or a rep
can arrange for samples. The one I found was in UK, IIRC, so maybe
that's not for you. I just needed some tech info.

There's 2 types, also. Self-oscillating and the one you supply a
tone to. If you try to apply a frequency to the former that is not
the same as the resonant freq, you may get the kind of unpleasant
discordance you're looking for. Maybe not.

Can you give us the specs of the one you've found? The 5mm part.

--
Best Regards,
Mike

 

OK, let me try once more... I keep losing my messages, a huge case of
user error.

The links to two products, I can't tell the difference:

http://www.ario.com.tw/catalog/product_info.php?products_id=152

http://www.ario.com.tw/catalog/product_info.php?products_id=158

If there's anything else out on the site that looks like what I need,
please let
me know.

Essentially, my problems are:
1) Don't know the part I'm looking for
2) Don't know what the specs mean to get what I'm looking for
3) Don't know the terminology or science
4) Can't find internet descriptions that I can understand
5) I've got to find the right size ( 5 - 6 mm diameter, max)

For instance, am I looking for a piezo, buzzer, sounder,
transducer, are they all one and the same? What kind of part?
What do I need to do to drive it?

What is the part called that chimes in a wristwatch?

Digi-Key and Mouser have piezo's that are too large. And
back to basics, I'm still not sure that's what I'm looking for.

The info about the two types, and that I don't have to drive
so hard is helpful and encouraging...

Tx,

George

 

Oh, yeah, and about that "over my head" part.

Basically, the device is a microprocessor, some buttons and an LCD.
While learning this is not "easy", it is well documented, and fairly
well supported. It doesn't take too long to get functional with those
things.

This sound thing though, is another story. I don't understand it, it
is not that well explained anywhere I can find, and so I'm swimming in
a sea of data with no way to convert it to meaning.

That's why I'm here.

Tx,

George

 

[Active8]

On 13 Mar 2005 13:19:14 -0800, scoremind@gmail.com wrote:

Hi Mike,

Yes, microcontroller, I am new at this... you're right.

As you have described, I haven't found any high level descriptions
(like "piezos can be used for creating beeps and buzzers" or "a
transducer can be used as a small speaker"), instead they are much more
detailed, including the Google define: descriptions. Ultimately, I'm
confident I'll understand what they mean, but for now, I'm afraid I'm
lost.

A piezo crystal flexes when you apply voltage to it, so when you
apply a varying voltage, it vibrates. That's the gist.

re: your PWM paragraph, this is exactly the kind of push-start I need
to simply point me in the right direction... I didn't want to go to the
trouble of getting some parts if they were not what I needed, and waste
a lot of time, as valuable as that might be in the long run. Thanks.

re: "not self-oscillating", you said earlier that was the kind I'd have
to supply a tone to...I'm guessing that your earlier description about
the PWM, the period and the duty cycle is how I would supply that tone?

Yup.

At

http://ww1.microchip.com/downloads/en/AppNotes/00538c.pdf

Yeah. I blew that app-note off because everything I needed to know
to implement PWM is in the datasheet for the chip in question. The
self oscillating piezos, buzzers, and sounders operate when you
apply a DC voltage. Regular piezos, speakers, transducers ( a
speaker is a transducer if you want to use the $20 word) operate
from an AC signal.

I found a discussion about attenuation. I don't pretend to understand
it right now, but I get the point that the output needs to be filtered
and adjusted. At any rate, it is specific enough, that with a little
bit of trial and error and documentation, I can probably stumble my way
into an answer.

KISS (keep it simple stupid) method is to rig a volume control (pot
or potentiometer) between the PWM out and the speaker and once you
get the volume level, measure the resistance between the wiper and
both ends and there's your attenuator.


View in fixed width font. See the link for that up top if posting
from google.

PWM ---+
|
.-. R1 .---|
| |<------| | just another transducer
| | +-| | or speaker symbol
'-'R2 | '---|
| |
| |
=== ===
GND GND

A piezo symbol would be more like
|
_-_
|___|
-
|

Just like a crystal.

PWM----+
|
.-.
| |R1
| |
'-'
|
| __ /|
+---------| | |
| +-|__|<->
.-. | \|
| |R2 |
| | |
'-' |
| ===
=== GND
GND
created by Andy´s ASCII-Circuit v1.22.310103 Beta www.tech-chat.de

Now about filtering. That thing you found has a voice coil of some
kind. Speakers don't like square waves. At least not anything that
pushes the limits. So what you do is filter the harmonics out to
make it more sinusoidal.


R
___
PWM -|___|----+----- out to attenuator (attn)
|
|
--- C
---
|
|
===
GND

<OT>
Proposed future IEC resistor symbol to appease PHBs who want one
symbol that's PC here and across the pond:

_____
-|/\/\/|-
----- <-- raise that line up.

I just proposed it per a prior poster's suggestion. Maybe JW or
someone will repropose it to whoever dreams that stuff up.
</OT>

Say you want tones from 1 kHz to 3 kHz... Square waves are made up
of odd harmonics, so the 3rd harm of 1 kHz is 3 kHz and you'd want
to filter that out. That will attenuate the 3 kHz tones you may or
may not want a bit, so you'll need to trade off range for sound
level or vice versa. OTOH, you can raise the cutoff freq above 3 kHz
and take some extra 3rd harmonic distortion ( not distortion of the
square wave, but of the ideal sine wave you never had to begin with,
so it's not really distortion ) and you'll still be ok. The more odd
order harmonics present in the signal in the correct proportions,
the more square it becomes.

The cutoff freq for the above filter is 1/(2piRC). That's where the
signal level will be down by 3 dB or "half power". I don't think we
need to get any deeper.

Thanks Mike,

Sure.

I'm happy to keep this thread open in case you think of anything else.
I've sent my first correspondence to the ARIOSE company, I'll see what
they have to say.

Good move. If you have any probs with mfg reps getting parts,
they'll probably do your bitching for you and light some fires.

If they confirm that it requires an AC voltage, I'll ( or just about
anyone here) figger out the details of the filter and attn for you.
Also get confirmation of WTF they mean with their operating and max
voltage specs. I would expect a peak to peak spec or an RMS spec,
not a peak spec like Vo-p. I'd expect Vpp or Vrms.

Rated Voltage(Vo-p): 3
Operating Voltage(Vo-p): 2.3 - 4
Current Consumption(mA): 100 max // does not compute with R below
Coil Resistance(Ί): 12 +/-3

2.3 * .707 / 12 = 135 mA, which exceeds the max current spec. Maybe
they need to put the crack pipe down.

Oh. Accuracy of your PIC timebase... I don't know what your game
does, but if you don't need accurate timing, you can use the
internal oscillator. Some PICs have a calibration word that makes it
even more accurate. You probably don't need a crystal. Not if it's
something like needing a timer to give the player a number of
seconds to respond. There's a few ways to do that with or without a
crystal.

I don't know what the PIC requirements are either. There's alot of
info on the net for the 16f84 and it's obsolete. 16f628A/648A or
16f88A are nice chips, though.

http://www.glitchbuster.com/

Randy ships fast and he won't rape your wallet. He's got PICs and
support parts. Info too.

www.piclist.com

is a good PIC info site. Great forum/mailing list for PIC and EE
questions. Lots of novices trying to flash LEDs and such, as well as
EE types.

I can't think of anything else, so I'm off.

See ya.
--
Best Regards,
Mike

 

[JeffM]

george.alvarez (aka scoremind) wrote:
[a post with no context]

Notice how Active8 includes part of your post when he responds?
People who don't read this at Google don't see Usenet the way you do.
Observe how others post and do likewise.

Something to read for a Usenet newbie who posts at Google:
http://groups-beta.google.com/group/sci.electronics.basics/browse_frm/thread/abf3f7038a2ef354/e08362c5b4fe45b5?q=Click-the-show-options-link+THAT-Reply-link+the-rule-book-for-Usenet+faqs-org+copy-paste-context

 

[Active8]

On 13 Mar 2005 23:48:52 -0800, JeffM wrote:

george.alvarez (aka scoremind) wrote:
[a post with no context]

Notice how Active8 includes part of your post when he responds?
People who don't read this at Google don't see Usenet the way you do.
Observe how others post and do likewise.

Yeah. Good point. The only reason I followed what was going on is
because I got into it from the git go.

Something to read for a Usenet newbie who posts at Google:
http://groups-beta.google.com/group/sci.electronics.basics/browse_frm/thread/abf3f7038a2ef354/e08362c5b4fe45b5?q=Click-the-show-options-link+THAT-Reply-link+the-rule-book-for-Usenet+faqs-org+copy-paste-context

IOW, the new google is hiding the quoted text. PITA. Good info about
the "show options" link in that OT seg of the thread.

I'd recommend 40tude Dialog for a news reader. You are using G2/0.2
(never heard of it. Linux?) and between the two, neither news client
mangled the long link he posted. That's cool.

If the OP doesn't like using his ISP's nntp server (slaver?) he can
try www.terranews.com for free unlimited posting since
individual.net is going to start charging. Must all good things come
to an end?
--
Best Regards,
Mike

 

[JeffM]

http://groups-beta.google.com/group/sci.electronics.basics/browse_frm/thread/abf3f7038a2ef354/e08362c5b4fe45b5?q=Click-the-show-options-link+THAT-Reply-link+the-rule-book-for-Usenet+faqs-org+copy-paste-context
||from the link:

::[for] context
::Easy way: Don't click the Reply link that is in plain sight.
::Click the **show options** link then click THAT Reply link

JeffM

IOW, the new google is hiding the quoted text. PITA.
Mike (Active8)

Well, I've always thought that the auto-blockquote "feature"

of newsreaders (and of the old Google Groups) gets (got) abused.
It makes folks lazy.
Shoot, when I'm paring down the old text
I often find things I missed the 1st time.
To me, a lack of context is preferable [1]
to gobs of extra junk (on which the response has no bearing).
I especially love it when ALL of a 200-line disertation is reposted
with a 4-word response.

I'd recommend 40tude Dialog for a news reader.
You are using G2/0.2 (never heard of it. Linux?)

That sucker is lying to you

--or is that their way of saying "2nd try at Google Groups"?

and between the two,
neither news client mangled the long link he posted. That's cool.
^^^^^^^^^^^^^^^^^^^ heh!

I have Super Gravity, but the only times I've used it was when

I responded to somebody who had cross-posted to a whole slew of groups
(Google won't allow responses to more than 5 groups)
and when the Google Groups Beta was new and I had problems
(I think I had AdBlock set too strict).

http://groups-beta.google.com/group/sci.electronics.design/msg/d662b1b174b55c01?dmode=source
Mostly I post at Google, so that shoots your theory all to hell.
(That's the reason I know so many Google tricks.)
I am, however, proof that someone can post at Google
and not look like a newbie.
[1] I actually like the interface.
I can see a lot at one time and get context, no sweat.
With the new low-latency updates
(to the thread displays--not to the searchable database)
it's not completely a pain the way it once was.

 

[Active8]

On 14 Mar 2005 02:08:32 -0800, JeffM wrote:

I said
snip

IOW, the new google is hiding the quoted text. PITA.
Mike (Active8)

Well, I've always thought that the auto-blockquote "feature"
of newsreaders (and of the old Google Groups) gets (got) abused.
It makes folks lazy.
Shoot, when I'm paring down the old text
I often find things I missed the 1st time.
To me, a lack of context is preferable [1]
to gobs of extra junk (on which the response has no bearing).
I especially love it when ALL of a 200-line disertation is reposted
with a 4-word response.

Right. How's this:

many blah blahs
y
blah
e
blah
s
blah
many more blahs ...

I'd recommend 40tude Dialog for a news reader.
You are using G2/0.2 (never heard of it. Linux?)

That sucker is lying to you
--or is that their way of saying "2nd try at Google Groups"?

The header of your post says:

User-Agent: G2/0.2

Ah!

Organization: http://groups.google.com

I didn't expect a user-agent header from google. WTF's the point of
it?

and between the two,
neither news client mangled the long link he posted. That's cool.
^^^^^^^^^^^^^^^^^^^ heh!

Oops! "He" should have been "you". My head's still up my ass.

I have Super Gravity, but the only times I've used it was when

I used to use that but the reader group posters were bitching about
the new versions and I gave it up. IIRC, it would alert me to
replies (yeah a filter rule/action thing) and that was cool, but
something got me wanting more so I looked into upgrading it. Now I
run a script in Hamster personal nntp server and it alerts me to
which group, subject, level, and poster - anything I can get from
the header info - and I can import the reply to an internal group I
create or a text file. You need a server like individual.net ( I
hope the terra server will do it) that allows you to use them as an
FQDN to generate the message ID - something like that. Dialog offers
scoring, and people use that to guess whether a post is a reply to
them, but I don't like that method.

<snip>

I actually like the interface.

It's getting fixed/improved and it isn't as bad as some have made it
out to be. MS, OTOH, ... FUBAR
<snip>
--
Best Regards,
Mike

 

Hey Jeff,

JeffM wrote:

george.alvarez (aka scoremind) wrote:
[a post with no context]

Notice how Active8 includes part of your post when he responds?
People who don't read this at Google don't see Usenet the way you do.
Observe how others post and do likewise.

Ok, like this, you're saying... this was the form that failed me
several times, not exactly sure why, but with any luck it works now.

Thanks for the tip.

Something to read for a Usenet newbie who posts at Google:

http://groups-beta.google.com/group/sci.electronics.basics/browse_frm/thread/abf3f7038a2ef354/e08362c5b4fe45b5?q=Click-the-show-options-link+THAT-Reply-link+the-rule-book-for-Usenet+faqs-org+copy-paste-context

 

[Active8]

On 14 Mar 2005 14:31:31 -0800, JeffM wrote:

<snip>

Quite a while back,
someone (Watt Sun, IIRC) was adding padding to his posts
to get arround some kind of filter.

If you mean one letter per line, it was either him or Genome. I
never figured out the purpose.

I, OTOH, say brevity is the soul of wit[1]
--make it as short as communicates the intelligence.

Ecomomy of words and motions is part of my philosophy. Sometimes I
fail on the former.

I hardly ever do the **<snip>** thing.
If I think editing the middle of the OP's post will leave a false
impression,
I use elipsises. (Man, it's hard to know when to stop typing on that
word.)

Elipsis

Otherwise, I chop out the excess.

Google is now flagging the posts that have the X-No-Archive bit set
so it's obvious which posts you need to blockquote in their entirety.

What just facinates the hell out of me
is when somebody reposts part of the original post
BELOW THE LAST SENTENCE HE HIMSELF HAS ADDED.

Dialog warns me of that. Sometimes I blow it off. Many times, it's
because the f*cking poster I'm replying to didn't use the double
hyphen above the signature, so it gets quoted.

<snap> (sic) Guess which book.
--
Best Regards,
Mike

 

[John Woodgate]

I read in sci.electronics.design that Active8 <reply2group@ndbbm.net>
wrote (in <656foaxzitfe.dlg@ID-222894.news.individual.net&gt about 'Can
anybody help?', on Tue, 15 Mar 2005:

Elipsis

Ellipsis.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[Rich Grise]

On Tue, 15 Mar 2005 03:00:12 -0500, Active8 wrote:

On 14 Mar 2005 14:31:31 -0800, JeffM wrote:
....
I hardly ever do the **<snip>** thing.
If I think editing the middle of the OP's post will leave a false
impression,
I use elipsises. (Man, it's hard to know when to stop typing on that
word.)
....
Elipsis

One ellipsis, two or more ellipses.

Cheers!
Rich

 

[Keith Williams]

In article <pan.2005.03.15.16.08.06.740442@example.net>,
richgrise@example.net says...

On Tue, 15 Mar 2005 03:00:12 -0500, Active8 wrote:
On 14 Mar 2005 14:31:31 -0800, JeffM wrote:
...
I hardly ever do the **<snip>** thing.
If I think editing the middle of the OP's post will leave a false
impression,
I use elipsises. (Man, it's hard to know when to stop typing on that
word.)
...
Elipsis

One ellipsis, two or more ellipses.

....O...

--
Keith

 

[JeffM]

One ellipsis, two or more ellipses.
Rich Grise

...O...
Keith Williams

Heh.
(Rich got where I was going.)

 

Active8 wrote:

On 14 Mar 2005 08:49:09 -0800, george.alvarez@gmail.com wrote:

Hey Jeff,

JeffM wrote:
george.alvarez (aka scoremind) wrote:
[a post with no context]

Notice how Active8 includes part of your post when he responds?
People who don't read this at Google don't see Usenet the way you
do.
Observe how others post and do likewise.


Ok, like this, you're saying... this was the form that failed me
several times, not exactly sure why, but with any luck it works
now.

Thanks for the tip.

Something to read for a Usenet newbie who posts at Google:


http://groups-beta.google.com/group/sci.electronics.basics/browse_frm/thread/abf3f7038a2ef354/e08362c5b4fe45b5?q=Click-the-show-options-link+THAT-Reply-link+the-rule-book-for-Usenet+faqs-org+copy-paste-context

That works. Often, If I see an OT thread or even one that's on topic
(or in our sister binaries group where I don't want to wait for the
OP to download), and I want to get an idea if I should check it out,
I'll jump to the middle and read a post from one of the bigger guns.
--
Best Regards,
Mike

Mike,

I wanted to take one more moment to thank you. I've found a local
supplier for a 5mm transducer, and both they and another vendor spoke
to me about exactly what I wanted, and explained the various
differences in parts, how they work, and what needs to be accomplished
in order to do what I want to do. Best of all, it was conveyed in
plain English, not the technical kind.

They are sending me a few samples, and basically, my job is to play
with the frequency in order to get the tone I want to hear.
Undoubtedly it will be more complicated than that, but I'm ready to get
started now and I've got some places to turn for help and guidance.

I appreciate you assistance a lot.

Tx,

George

 

[Active8]

On 13 Mar 2005 08:36:36 -0800, george.alvarez@gmail.com wrote:

OK, let me try once more... I keep losing my messages, a huge case of
user error.

If posting from google... YMMV. ISPs, same. I used to change
Earthlink servers when they fouled up.

The links to two products, I can't tell the difference:

http://www.ario.com.tw/catalog/product_info.php?products_id=152

http://www.ario.com.tw/catalog/product_info.php?products_id=158

Anyone want to give a second opinion on whether those little
speakers are made for AC input as opposed to self-oscillating
piezos?

If there's anything else out on the site that looks like what I need,
please let
me know.

Maybe when I have time later. Those two buggers above look like they
only differ by the freq response.

Essentially, my problems are:
1) Don't know the part I'm looking for
2) Don't know what the specs mean to get what I'm looking for
3) Don't know the terminology or science

Google every word you don't understand. First keyword "define" with
no quotes sometimes works well.

But those parts above are not piezo devices. They could very well
work, though. I can't find anything that small in piezo in my cats,
so I'm ready to recommend trying it. If by microprocessor, you mean
microcontroller, like a PIC or Atmel AVR, you're in like Flynn. One
trick is to use the PWM output and vary the period (1/freq) while
holding the duty cycle at 50%. Then you can make any tone you want
withing the freq response of the noise maker. The flattest part of
the response curve will give you the least variation in sound
pressure level. It might not look flat, but practically speaking,
the lower part of the curve looks like the range you'd want for
chimes. Say 1-3 kHz. That's an octave and a half. You could go lower
probably.

PWM - Pulse Width Modulation.

It also looks like the max and operating voltages are specified as
peak voltage and they give a coil resistance, so I doubt it's
self-oscillating. The package, however, dictates the resonant freq,
and operating away from that may or may not sound weird. I doubt
they're too expensive, so they may be worth a try.

4) Can't find internet descriptions that I can understand

Much of it's more technical than you need.

5) I've got to find the right size ( 5 - 6 mm diameter, max)

You have, IMO.

For instance, am I looking for a piezo, buzzer, sounder,
transducer, are they all one and the same? What kind of part?
What do I need to do to drive it?

Forget buzzers and sounders. Drive it like I said above (PWM).
You'll probably need to attenuate the PWM output. I gotta run, so
I'll think about it more later and we can talk about attenuation.

What is the part called that chimes in a wristwatch?

I always assumed they are piezo devices. I could be wrong.

Digi-Key and Mouser have piezo's that are too large. And
back to basics, I'm still not sure that's what I'm looking for.

The info about the two types, and that I don't have to drive
so hard is helpful and encouraging...

--

Best Regards,
Mike