can anyone help me how to select the right ultrasonic sensor for my project.(what variable have to consider? How to estimate the area covered by the ultrasonic signal at given distance, for example 1 meter?)
if i want to build the ultrasonic sensor myself, can anyone teach me how to do

 

Just buy one. You don't have much selection in the "cheap" price range and they are very cheap. The price hangs around $30-$50 and then there is a massive empty gap and where the next expensive thing is >$500.

The best kinds I've seen are here:
http://www.robot-electronics.co.uk/s...angers1999.htm

This is just the company that makes them. Many other companies sell their products so you can get more local currency, pricing, shipping, etc.

Acroname, Robotshop Canada, Jameco Robot Store, and many other places carry them.

 

there are tons of schematics and tutorials on the net. PLEAS START USING THE SEARCH ENGINES! Google is the one i use...

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Voltage?
Power level?
Frequency?

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i manage to get a ultrasonic transceiver. its part number is MA40S5, manufactured by MURATA. its specification is like this:

construction: open structure
using method: dual use
nominal frequency: 40kHz
overall sensitivity: 20 mVp-p typical
sensitivity(dB): -
S.P.L (dB): -
Directivity: 60 degree typical
capacitive: 2550 pF
Operating temperature range: -30 to 85 celsius
detectable range: 0.5 to 2 meter
Resolution: 9mm
Maximum input power(Vp-p): 20 pulse width 0.4ms interval 100ms

if i want to fix detectable range to 0.5 meter to build my prototype first, how my circult of ultrasonic transceiver look like, or what parameter i should take care when build this circuit?

for full datasheet, look at page 20 of its datasheet or goto MURATA wedsite.

 

i am also using murata ma40s5 for my final year project. the problem is how do i build the circuit in order to obtain the output??

 

It is your final year!
Design an ultrasonic FM transmitter.
Design an ultrasonic FM receiver.
Design a pcb for each and make it.

I didn't search through Murata's website to find the datasheet for the sensor to see its bandwidth.

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ultrasonic transceiver works by transmitter sending signal then measure duration for the signal to arrive at the receiver, which is proportional to the distance

 

His "tranceiver" is really a distance measuring device?
I thought he was voice communicating with ultrasonics.

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I am interested in ultrasonic FM. Can anyone provide help of circuits and demodulators.

walter

 

If you read the rest of the thread you took the quote from, you will notice that everyone said it was a stupid idea! - and it still is!.

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following is the circuit diagram of the UltraSonic sensor circuit and breif explaination



C ircuit of a new type of remote control switch is described here. This circuit functions with inaudible (ultrasonic) sound. Sound of frequency up to 20 kHz is audible to human beings. The sound of frequency above 20 kHz is called ultrasonic sound. The circuit described generates (transmits) ultrasonic sound of frequency between 40 and 50 kHz. As with any other remote control system this cirucit too comprises a mini transmitter and a receiver circuit. Transmitter generates ultrasonic sound and the receiver senses ultrasonic sound from the transmitter and switches on a relay. The ultrasonic transmitter uses a 555 based astable multivibrator. It oscillates at a frequency of 40-50 kHz. An ultrasonic transmitter transducer is used here to transmit ultrasonic sound very effectively. The transmitter is powered from a 9-volt PP3 single cell. The ultrasonic receiver circuit uses an ultrasonic receiver transducer to sense ultrasonic signals. It also uses a two-stage amplifier, a rectifier stage, and an operational amplifier in inverting mode. Output of op-amp is connected to a relay through a complimentary relay driver stage. A 9-volt battery eliminator can be used for receiver circuit, if required. When switch S1 of transmitter is pressed, it generates ultrasonic sound. The sound is received by ultrasonic receiver transducer. It converts it to electrical variations of the same frequency. These signals are amplified by transistors T3 and T4. The amplified signals are then rectified and filtered. The filtered DC voltage is given to inverting pin of op-amp IC2. The non- inverting pin of IC2 is connected to a variable DC voltage via preset VR2 which determines the threshold value of ultrasonic signal received by receiver for operation of relay RL1. The inverted output of IC2 is used to bias transistor T5. When transistor T5 conducts, it supplies base bias to transistor T6. When transistor T6 conducts, it actuates the relay. The relay can be used to control any electrical or electronic equipment. Important hints:
1. Frequency of ultrasonic sound generated can be varied from 40 to 50 kHz range by adjusting VR1. Adjust it for maximum performance.
2. Ultrasonic sounds are highly directional. So when you are operating the switch the ultrasonic transmitter transducer of transmitter should be placed towards ultrasonic receiver transducer of receiver circuit for proper functioning.
3. Use a 9-volt PP3 battery for transmitter. The receiver can be powered from a battery eliminator and is always kept in switched on position.
4. For latch facility use a DPDT relay if you want to switch on and switch off the load. A flip-flop can be inserted between IC2 and relay. If you want only an ‘ON-time delay’ use a 555 only at output of IC2. The relay will be energised for the required period determined by the timing components of 555 monostable multivibrator.
5. Ultrasonic waves are emitted by many natural sources. Therefore, sometimes, the circuit might get falsely triggered, espically when a flip-flop is used with the circuit, and there is no remedy for that

Attached Images

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Is this your design?

Somehow I doubt it is.

Could you please post a link to the website from where you have acquired it?

Because your technical write up isn't very good.

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Here is the link:
http://www.reconnsworld.com/ir_ultra...traswitch.html

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Thanks epilot.

Perhaps we should encourage (or even mandate) people to sight where they got circuits from, even if it's just by using [img] tags.

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