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rohitd
10-11-2005, 10:55 AM
hi,

i bought a ultrasonic sensor pair but it has not got a part number on it,the shopkeeper told me it was of number pd-45,sp-55,can any one give me details about thes transducers, also can any one tell me is it having any polarity,because one of its pin is connected to case,so should that pin be grounded, in forum one circuit was discussed,which showed that a puspull configuration is used to drive the ultrasonic trnsducer,can i drive the transmitter by simply giving pulses of 0 to 6 v to one pin and grounding the other pin.also what min/max current it will take .
i am sending the link where i got the circuit http://www.interq.or.jp/japan/se-inoue/e_pic6_6.htm

please its urgent.
thanking you rohit

docel
10-11-2005, 11:47 AM
It is just another speaker, optimised for 40khz. You must know that speakers work optimal when the manuf polarity is followed...
PiezoDetectorSenderPiezo. number denotes freq, usually in Khz.

Also, make it a habit SEARCH forums, You'll learn before you ask!!!
Lots of info on this on this Forum and good tutorials, too.

http://www.google.co.in/custom?domains=www.roboticsindia.com&q=ultrasonic&sa=Search&sitesearch=www.roboticsindia.com&client=pub-7381293924338791&forid=1&ie=ISO-8859-1&oe=ISO-8859-1&cof=GALT%3A%23008000%3BGL%3A1%3BDIV%3A%23336699%3B VLC%3A663399%3BAH%3Acenter%3BBGC%3AFFFFFF%3BLBGC%3 A336699%3BALC%3A0000FF%3BLC%3A0000FF%3BT%3A000000% 3BGFNT%3A0000FF%3BGIMP%3A0000FF%3BFORID%3A1%3B&hl=en

rohitd
10-11-2005, 12:32 PM
hi dosel,
thanks for the reply.
ya i do search the forums but ask when dont get the expected explanation.

one of my question was unanswered though
,can i drive the transmitter by simply giving pulses of 0 to 6 v to one pin and grounding the other pin.also what min/max current it will take or push pull is necessary.

thanks
for replying
rohit

docel
10-11-2005, 01:02 PM
hi,
YES.
It also depends on your application. You may need symmetrical pulses, AC pulses without distortion, varying DC pulses... modulated ...pulses. and be driven between a bridge driver, grounded, ttl, collector, emitter etc. The body should always be at reference signal.
Treat the transducer like a speaker with a built in filter: it will respond ONLY to the centre freq, ie., 40khz, 38Khz etc.
The ultrasonic transducer is just a capacitor : 2 plates separated by a piezo element dielectric. i plate is + or signal pin and the other is grounded to body. This is for shielding purposes. This 'Cup" shielding giveas it some directional property, otherwise it will respond to sigs from the wanted direction plus sigs from reflections, which leads to a confused sensor!

They work fine, any way you connect, but there are benefits depending on the where and the what-for.

rohitd
10-11-2005, 01:13 PM
thanks dosel,
it was of great help.
rohit
kharafriend@yahoo.com

docel
10-11-2005, 01:21 PM
You're welcome.
...and RohitD, my user name is docel...

asimov_18
10-30-2005, 12:43 AM
hi rohitd its nice you have put up this question about ultrasonic tx and rx.
i wish to ask u one question, where did u purchase this ultrasonic transducer(shop and city with telephone no is possible). and what was their price this would be a lot of help to many of us who wish to purchase these devices
thanks
asimov_18