I don't know where to buy Velleman stuff. Digikey sells ultrasonic transducers for $26.00US to $120.00US.

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Uncle $crooge

 

Those are prices for something different, the transducer shown is fairly cheap!.

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PIC programmer software, and PIC Tutorials at:
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what about using a normal loudspeaker?

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Might reach 20KHz on a good day?. What EXACTLY are you trying to do?.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

That little 0.25W thing isn't a speaker, it's a shrieker.
The digital clock radio that I bought for only $.99 has a bigger one (and makes a bigger shriek). :lol:

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Uncle $crooge

 

ok it seems the idea of a 100 khz range meter is not possible

there is alot of loudspeakers in any size, any shape and any....
then i call all them "speaker" i am not family with all names of speakers..

so let me know what kind of speakers are good for a range between 25 to 50KHz rather than a ultrasonic sensor?

 

We can't hear frequencies from 25kHz to 50kHz so nobody makes a speaker go so high. An expensive tweeter might go as high as 25kHz but it is fragile and can't handle much continuous power. It can produce "tick" sounds loudly. A continuous loud tone would destroy it.

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Uncle $crooge

 

i have found a site that sells some kind of ultrasonic speakers(sounders)
at: http://www.myntahl.com/piezo_Ultrasonic.htm

those ultrasonic speakers can handle 50KHz MAX but i dont know wht they are or from where i can get them???!!!

o yes tweeters can not handle more than 22KHz Unfortunately

 

hey am i right?

it seems these peizo transdusers work at 46KHz freq :shock:


http://luguang.en.alibaba.com/offerd...o_Buzzers.html

 

The 1st one have reps in USA, Canada and Latin America. They have extremely narrow-band resonance that would need very fine frequency tuning and matched devices for any range.

The 2nd one has no detailed spec's and you must buy a min of 10,000.

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Uncle $crooge

 

Try to find out more about the transducers used by Velleman you showed before. Find out about their kit:

Attached Images

parking_radar.png (166.3 KB, 312 views)

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Uncle $crooge

 

that is not so good becuase i can not buy them via that countries.

for what job those sounders are made?

 

WoW, see these tweeters they act at 100KHz :shock:

http://www.murata.com/catalog/p57e.pdf


i hope i could find them here they seems to be very interesting for a rangemeter,

 

The larger good Murata tweeter is really good (if they didn't smooth its frequency response graph too much). It seems to need an awful lot of power for its fairly low volume output. They don't say what its capacitance is, which is probably pretty high, requiring high current at high voltage. Get many because continuously at full power it doesn't last very long.

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Uncle $crooge

 

although i have no access to online shpping but now i am a bit HOPEFUL finding a thing like them here, i will go and see what kind of tweeter i can find,

if i could fnd a suitable tweeter then i must find a circuit to go it at resonant position, am i right?

thanks alot for taking part