design and parts ?

[jamesgangnc]

I want to build the killer of all dog bark stoppers.  (Sorry to any dog lovers but we have neighbors with two dogs that they leave in a fenced yard and they bark at anything that happens within a 1/2 mile day or night.)  I already have a device I bought that is tripped by barking and has a couple piezo tweeters in it.  Not enough power though.  I've got a power supply I salvaged out of some com gear that does 70 amps of +5 so I was thinking I could use some high current power transistors to run a whole bunch of those cheap piezo tweeters in parallel.  I can adapt existing circuits and combine designs but designing from scratch is a little beyond my skills.  Also I need parts suggestions for the power transistor.  I know I need an amp design that has a lot of current gain, not voltage gain.  And something I can run several of the amp circuits in parallel if I need to.  I was planning to drive it from the output circuit of the existing bark stopper unit if I can.  Otherwise if I need to I can interject some opamps (741s) or common low power transistors like the 2n2222 or 2n2907s to drive.  I have a old tectronix 5mhz scope and digital multi-meter and a collection of basic parts.  Figuring I'll have to get the power transistors from newark. 

 

I'd previously been thinking about running a bunch of the piezoes in series and using the 115v mains directly into dc with some sort of high voltage amp circuit but then this 70 amp 5v power supply came along.  Figured it's be a lot safer that rectified mains.

 

Anyone want to give me some pointers?

[JeffM]

jamesgangnc wrote:
>I want to build the killer of all dog bark stoppers.

>[...]we have neighbors with two dogs that they leave in a fenced yard

>and they bark at anything that happens within a 1/2 mile day or night.)

>[...]been thinking about running a bunch of the piezoes in series and[...]

...and, you think that AGGRAVATING the animals FURTHER
will make them QUIET.

There are surely laws on the books where you are
which deal directly with irresponsible pet owners
and with noise abatement.
Make 2 telephone calls, first to the police then to Animal Control.
After the authorities are finished talking to the people,
have the cop give you a copy of the report
which includes the case number and name of the responding officer.

If the problem happens again,
make the calls again, this time using the previous case number.
Request that the same cop respond.
The people will be given a date to appear in court
where they will pay (in money and time) for their bad behavior.
Get a copy of the report on this incident as well.

If it happens a 3rd time,
reference the 2 previous reports and request that the dogs be removed.

[jamesgangnc]

Actually the original device did work. They would stay away from the
section of the yard closest to our house if they barked while I was
using it. Problem was they continued to bark towards the back and on
the other side of the yard. That's why I want to crank up the power.
The original device creates a variable sound that fluctuates between
20 and 50 khz. It's trigger by loud, low frequency sounds. It might
aggravate dogs, but they definately will move away from the source of
the sound. I've seen it work. Some of our friends in a denser
neighborhood with small yards have one and if the dog next door to
them starts barking and sets it off, that dog goes straight back it's
house door and starts whining to get back in the house.

Noise abatement laws and enforcement vary from locality to locality.
In our area, police don't handle barking bogs, animal control does.
Like most places, our animal control is understaffed and often takes
hours to respond to a call if they ever do. If the dog in question in
not outside barking when they get there then it doesn't count. Just
because you report it does not matter. And there is very little
escalation even when they do find a barking dog.

So, you got any suggestions that would help me build a high power
current amp?

Sorry to the responsible dog owners out there if I've offended. But
some people just don't care that their dog barks at everything all
day.

[BobG]

The motorola peizo 'super horns' are capacitive in nature... thats why
you can hook them across a speaker... they self-cross over at about
2khz. They will tolerate about 20V. So get a +-20V sawtooth wave out
of a functioon generator and drive 4 or 8 of those tweeers in
parallel. Dont hook em up in series. Caps in series get smaller.

[Bob Monsen]

This reminds me of a story I read about the legendary Bob Widlar. Apparently, he liked his office to be quiet. However, co-workers would come in and try to talk to him while he was working. So, he built a device that listened for voices, and while the offender was speaking, would put out an annoying but quiet high pitch whine. As soon as the person stopped talking, the whine would stop. So, while the device was on, folks would walk into his office, and start talking, but would immediately stop, noticing something out of the ordinary. They would try again, and perhaps one more time, and then eventually walk out of the office shaking their heads, unable to figure out why they felt odd when trying to talk to Bob.

 

(I think I read this in Bob Pease's book "Troubleshooting Analog Circuits")

 

BTW, your idea will wake up every dog within a mile, and they'll all start barking. Buy some noise cancelling headsets, a gun, or perhaps some cotton. Or make friends with your neighbor and get them to walk their dogs.

 

Regards,

 Bob Monsen

"jamesgangnc" <ja...@nospam.com> wrote in message news:13r5u73...@corp.supernews.com...

[John Fields]

On Wed, 13 Feb 2008 09:02:15 -0500, "jamesgangnc" <ja...@nospam.com>
wrote:

---
Start by talking with your neighbors about the problem. Not just
the ones with the dogs, but also the ones around them who must also
surely be annoyed by the barking.

That way, if the dogs' owners decide to go belligerent and refuse to
quiet them you'll have a coalition whose complaints to animal
control will surely rouse them from the torpor you mentioned in
another thread.

--
JF

[Jamie]

JeffM wrote:

Yup and mean while as this is going on, you'll get egged ,threaten,
harassed with no proof at all. They'll watch you like a hawk looking for
any little thing they can call you on..

It's not worth being a jerk with people that have miss behaved
animals. All that happens in the end is the animal ends up in a
place most likely destine for the bone yard. If you want that on
your conscience then fine, I guess that makes you no better than they
are.

--
"I'd rather have a bottle in front of me than a frontal lobotomy"

"Daily Thought:

SOME PEOPLE ARE LIKE SLINKIES. NOT REALLY GOOD FOR ANYTHING BUT
THEY BRING A SMILE TO YOUR FACE WHEN PUSHED DOWN THE STAIRS.
http://webpages.charter.net/jamie_5"

[Jamie]

jamesgangnc wrote:

Instead of doing all this crap which will most likely stir up more of a
mess.
Work out something with your neighbor to place barking collars on the
dogs until the dogs understand the limits of barking.
once that is done. The collars can be removed and fake one's put on..

It does work!.

What you're doing is not only hurting their ears but the ears of other
animals that are not causing a problem and thus does make others
actually bark in the attempt to kill the noise.

--
"I'd rather have a bottle in front of me than a frontal lobotomy"

http://webpages.charter.net/jamie_5"

[jamesgangnc]

Nope, dogs try to get away from these device.  They learn to associate their barking with the annoying sound just like the bark collars that shock.  Neighbor isn't the type that cares.

"Bob Monsen" <rcmo...@gmail.com> wrote in message news:5oLsj.10123$Ch6....@newssvr11.news.prodigy.net...

[jamesgangnc]

Been thoses routes, ineffective. The unit I got made more progress to
fixing the problem that anything else. I just want to extend it's range.
Got any suggestions for a high current transistor and amp circuit that would
let me leverage this 5volt power supply?

"John Fields" <jfi...@austininstruments.com> wrote in message
news:3137r3tme5j1m7rat...@4ax.com...

[jamesgangnc]

Neighbors could care less. They wouldn;t put bark collars on their dogs if
I paid for them. Besides these units are just another form of conditioning,
they bark, the noise starts. It shuts off by it's slef after a minute or so
until they bark again. I just need to extend the range. Got some
suggestions for a power transistor and circuit that would let me leverage
this big 5v power supply I have?

"Jamie" <jamie_ka1lpa_not_v...@charter.net> wrote in message
news:yvMsj.58$El3...@newsfe06.lga...

[jamesgangnc]

I knew I'd get some grief about this but was hoping someone would help with parts and circuit suggestions.

 

The neighbor in question has been a problem for a long time.  The only noise laws we have on the books are designated hours at night.  They simply take the dogs in then.  The allowable daylight hours are pretty broad and make no consideration for weekends.   Besides, how enjoyable is being out on you deck in the afternoon with friends only to have dog barking interrupt you constantly?  I'm at the end of a street and we all have big lots.  The nieghbor on the other side of me and the neighbor on the other side of the problem don't have dogs.  There is a public trail running through the wood behind us.  It makes the situationn worse because the dogs bark at every one jogging or walking on that trail until they are out of sight.  We have a cat so we're not without some sympathy for animals.  But let's be realistic, thousands of unwanted cats and dogs are simply killed every day.  They are just animals. Millions of other animals are killed daily just for us to eat. 

 

I know I can find lots of simple class ab power amp circuits on the internet.  But I would need to make a power supply for them.  The power limit is the power supply and it gets expensive to make a power supply for high watt amps.  So that's why I wanted to figure out a way to use the high amp 5v power supply I've already got.

"jamesgangnc" <ja...@nospam.com> wrote in message news:13r5u73...@corp.supernews.com...

[Bob Masta]

On Wed, 13 Feb 2008 09:02:15 -0500, "jamesgangnc" <ja...@nospam.com>
wrote:

>I want to build the killer of all dog bark stoppers. (Sorry to any dog =
>lovers but we have neighbors with two dogs that they leave in a fenced =
>yard and they bark at anything that happens within a 1/2 mile day or =
>night.) I already have a device I bought that is tripped by barking and =
>has a couple piezo tweeters in it. Not enough power though. I've got a =
>power supply I salvaged out of some com gear that does 70 amps of +5 so =
>I was thinking I could use some high current power transistors to run a =
>whole bunch of those cheap piezo tweeters in parallel. I can adapt =
>existing circuits and combine designs but designing from scratch is a =
>little beyond my skills. Also I need parts suggestions for the power =
>transistor. I know I need an amp design that has a lot of current gain, =
>not voltage gain. And something I can run several of the amp circuits =
>in parallel if I need to. I was planning to drive it from the output =
>circuit of the existing bark stopper unit if I can. Otherwise if I need =
>to I can interject some opamps (741s) or common low power transistors =
>like the 2n2222 or 2n2907s to drive. I have a old tectronix 5mhz scope =
>and digital multi-meter and a collection of basic parts. Figuring I'll =
>have to get the power transistors from newark.=20
>
>I'd previously been thinking about running a bunch of the piezoes in =
>series and using the 115v mains directly into dc with some sort of high =
>voltage amp circuit but then this 70 amp 5v power supply came along. =

>Figured it's be a lot safer that rectified mains.
>
>Anyone want to give me some pointers?

I suspect that you don't need anything in the way of waveform fidelity
for this application, so your amplifier doesn't need to be anything
more than a switching transistor. I imagine that is what the
commercial unit uses already, so you may be able to poke around inside
it and find a decent drive signal. It should be a rectangular wave
running between ground and the positive supply voltage.

Probably just about any TO-220 or similar NPN power transistor
will work. Connect the drive signal to the base through 1K or so,
ground the emitter, and connect the piezo unit between the collector
and the positive supply.

I am assuming here that the piezo units are not self-contained buzzers
that produce a fixed frequency when DC is applied. If so (and you buy
more just like them) then the same simple switching circuit will still
work, except that the drive signal will be a DC level that lasts as
long as the sound is supposed to last.

Note that piezo devices in general are low current, high voltage
devices, so depending on the exact model they may do better with more
than 5V. (But getting decent specs is difficult.) They also don't
put out a lot of power, but a whole lot of cheap piezos may still be
cheaper than a high-power dynamic super-tweeter.

Of course, all cheap piezo tweeters don't have the same frequency
reponse, either, so you may want to experiment with a few different
models.

Best regards.

Bob Masta

DAQARTA v3.50
Data AcQuisition And Real-Time Analysis
www.daqarta.com
Scope, Spectrum, Spectrogram, FREE Signal Generator
Science with your sound card!

[jamesgangnc]

>         Science with your sound card!- Hide quoted text -
>
> - Show quoted text -

Thanks for the advice. You are absolutely correct, sound quality is
not an issue. I doubt the unit I'm planning to drive it with has a
very clean sine wave. Would you put a capacitor in the circuit
between the source and the npn transistor as well? I don't need any
sort of bias? How many do you think I can hang off one TO-220? Yes
the tweeters are those cheap piezo ones, not buzzers. Something like
these;

http://www.fcsurplus.ca/shopping/shopexd.asp?id=16013

[JeffM]

jamesgangnc TOP-POSTED
(without any marking to show who posted what):
>[a huge mess]

Your posting style SUCKS.
http://www.google.com/search?q=cache:bLfLqbwDHOQJ:www.mozilla.org/community/etiquette.html+in.logical.order+Us+after.the.text.you.are.commenting.upon+remove.extraneous.material+Top-posting

Ah.
http://groups.google.com/group/sci.electronics.basics/msg/b5a8ff210b586310?dmode=source
It might help if you would configure the PoS tool you use.

[Bob Masta]

On Thu, 14 Feb 2008 10:56:32 -0800 (PST), jamesgangnc
<james...@earthlink.net> wrote:

>
>Thanks for the advice. You are absolutely correct, sound quality is
>not an issue. I doubt the unit I'm planning to drive it with has a
>very clean sine wave. Would you put a capacitor in the circuit
>between the source and the npn transistor as well? I don't need any
>sort of bias? How many do you think I can hang off one TO-220? Yes
>the tweeters are those cheap piezo ones, not buzzers. Something like
>these;
>

>http://www.fcsurplus.ca/shopping/shopexd.asp?id=3D16013

Couldn't get that link to work, so I can't comment on the specific
part.

No, you don't need (or want) any capacitor or bias on the driver
transistor... it's just acting as a simple switch. When the input
is at ground, it's off. When the input rises a few volts it goes
fully on. Note that this depends upon the signal being a clean
rectangular wave swinging between ground and positive supply...
not a regular bipolar AC signal and definitely not a sine wave.

As far as how many tweeters you can hang off one TO220, "that
depends"... but probably several. Try experimenting and seeing how
warm it gets. If the signal frequency is too high to hear, you may
want to test your circuit with a somewhat lower frequency so you can
be sure everything is working OK. Again, it must swing between ground
and the positive supply. You may be able to lower the drive frequency
by locating the capacitor in the oscillator stage and jumpering a
larger one across it. Or, if you can get the appropriate signal from
a benchtop signal generator, use that. If you have a proto-board and
a couple of CMOS gates, you can rig up a simple oscillator to do the
job. (Post back if you need a circuit, but I suspect there are plenty
on the Web. The "CMOS Cookbook " by Don Lancaster is an excellent
source for this kind of thing.)

Best regards,

[steve]

There is a reason(s) why dogs bark.

It may be due to loneliness, exercise (lack of), etc., but usually NOT
to attract attention.

Being nice to the owner should be a tried, by advising about the dogs
getting a varying environment.

Yours sincererly

Steve