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ultra sonic circuit application

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MrDEB

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I have my basic CRITTER RIDDER circuit using a PIC to generate a 3-6khz frequency.
Now am wanting to apply to an automobile but the little 1 1/8" speaker won't cut the mustard.
Looking at using a Pienzo tweeter instead but needs amplification.
found two circuits that produce high frequencies (would really like to combine ultrasonic with the 2-6khz. mix the two sounds together?
Amplifiers = looking at the TAD2003 10w unit. as well as the push-pull circuits in the links.
not real knowledgeable on sound etc subjects.
any advice would be helpful.
the one circuit uses a transformer but gives only winding counts sand wire size (am sure there is a method of figuring what transformer to purchase.
https://www.electronic-circuits-diagrams.com/homegardenimages/1.gif
Ultrasonic pest repeller
 

mvs sarma

Well-Known Member
I have my basic CRITTER RIDDER circuit using a PIC to generate a 3-6khz frequency.
Now am wanting to apply to an automobile but the little 1 1/8" speaker won't cut the mustard.
Looking at using a Pienzo tweeter instead but needs amplification.
found two circuits that produce high frequencies (would really like to combine ultrasonic with the 2-6khz. mix the two sounds together?
Amplifiers = looking at the TAD2003 10w unit. as well as the push-pull circuits in the links.
not real knowledgeable on sound etc subjects.
any advice would be helpful.
the one circuit uses a transformer but gives only winding counts sand wire size (am sure there is a method of figuring what transformer to purchase.
https://www.electronic-circuits-diagrams.com/homegardenimages/1.gif
Ultrasonic pest repeller

Perhaps you may use a 555 to generate Ultrasonic frequency you need
and apply the 2-6KHz at its pwm pin (pin5) thereby you get a modulated Ultrasonic frequency
if the pic generated 2-6KHz is a square wave, you may also use it to switch pin4. to get a switched Ultrasonic frequency by the 2-6Khz .
 

MrDEB

Well-Known Member
now I am lost

I assume your applying the output of the PIC to the 555 to mix the ultrasonic w/ the 2-6khz??
what about amplification?? the PIC is not very loud (dealing with road noise )
I may be over designing but ??

not sure how the push pull works relating to efficiently etc.
was thinking along the lines of 1/2 the push pull connected to the PIC and the 555 (20khz is what the piezo speaker states)
Piezo Tweeters
looking at the GT1016 for $1.70.
 

audioguru

Well-Known Member
Most Helpful Member
45 years ago those cheap piezo tweeters were used on low quality guitar speakers.
Their frequency response is all over the place due to many resonances and nulls.
They respond from about 3.5kHz to about 20kHz. Lower and higher frequencies are reduced in level.

Their sound pressure output is rated as though they are driven with a sine-wave into an 8 ohm speaker. So 1W is 2.83V RMS into 8 ohms. Your signal is a square-wave so 1W will be 8V peak-to-peak.

The output from a PIC is 5V peak-to peak so the tweeter will not be loud, it will be about 86dB at a distance of 1m for mid-frequencies. 2kHz will barely be heard.

The output from a TDA2003 amplifier that has a 12V supply is about 10V peak to peak which is not much louder than the tweeter being driven from a PIC.

The tweeter is rated for a max power of 50W which is 56V peak-to peak. Then at a distance of 1m its sound pressure is 111db which is extremely loud.

At 2m the sound will be 105db.
at 4m the sound will be 99dB.
At 8m the sound will be 93dB.
At 16m the sound will be 87dB which is not loud.

You could use a bridged amplifier like a TDA2005 with a 15V supply. Its output will be about 26V peak-to-peak. The piezo tweeter will have a sound pressure of 80dB at a distance of 16m. A faint beep.
 

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MrDEB

Well-Known Member
an automobile only has 12v

another problem is if it is too loud then maybe I would be breaking the law as far a a siern being used??
A deer can hear up to 1 mile away so perhaps the tda2003 or maybe a push pull amp??
would the push pull produce a louder tone??
 

Sceadwian

Banned
Just a side note, 3-6k is no where near ultra sonic, so the thread title is a misnomer.
 

audioguru

Well-Known Member
Most Helpful Member
Nearly all amplifier outputs are push-pull. The output pushes high then pulls low.
I think you mean "bridged".
The circuit with four output transistors is bridged.

A bridged amplifier has double the output voltage swing as an amplifier that is not bridged. Then the sound level is 6dB louder.
 

audioguru

Well-Known Member
Most Helpful Member
The datasheet from Sure Electronics has a very bad translation from Chinese. I can't understand it.
 

MrDEB

Well-Known Member
join the party

after tinkering with PIR I find it triggers due to sunlight.
Motion will trigger it in the house but sunlight just keeps triggering the unit.
maybe insert a cds in series w/ the Vcc or ? of the PIR to shut it down in daylight.
unless someone else has an idea??
there are two deer sitting under a tree in neighbors yard of test sight and they definitely are annoyed by sound (their ears kept moving and they kept moving around nervously.
need to shut the unit down in daylight.
 

MrDEB

Well-Known Member
a different approach to motion detection??

started thinking out side the box
what about sensing foot traffic?
found several websites that have circuits that use geophones or homemade geophones using a speaker or large magnets.
how does he idea of a IR/detector sensing the movement of a weight tied to a string (think semic detection)
a long tube (pipe) with the detection device at end of pipe. the weight moves thus triggering the IR detector.
the string has black tubing in the detection area to enlarge the surface being detected by the IR / detector unless a string is big enought to trigger the IR / detector.
Circuit - Human Traffic Footstep Detecto - Circuits designed by David A. Johnson, P.E.
Circuit - Earthquake Alarm Hobby Circuit
problem is wind?? unless I detect the horzontial movement of the string??
 
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