CA3140 IC substitute value

godfreyl said:

I guess you live in India. If so, you can buy them from RS online.

Here is a good transmitter.

Here is a good receiver.

They each cost about 400 rupees. Before you complain, those are the cheapest ones.

Here's two different datasheets that describe them:
Datasheet1
Datasheet2

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naa naa no complain sir , actually people are complaining before me . .

Too today i mate some more people & observed same issue that availablity of required components are rare or costly
so all are challenging before my mission to design things in such a way

All make me dipressed that its impossiblle,dats impossible,etc etc etc

but i still say "I M POSSIBLE"

See you make a lilttle thing possible here . . .
but its not a major issue for you & me cause have a broad thinking but now its my turn to connect narrow minded people with real technology which they too can design of thier own


Well coming to point what about related circuits ??

i mean proper one . . cause all you know what i ve posted earlier . . so . . . . .

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FvM said:

I presume, you get cheaper US transducers than Murata brand from DIY electronics shops. Probably with a less exact specification.

e.g.

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hmm ya its a better option but why the diffrence in rate here ??

Is the quality matters ?

or what ???


what about the proper circuit diagram after all these ?

1) You need a simple oscillator made with a 555 IC. It can directly drive a piezo ultrasonic transmitter. if the voltage is too low then it can be easily doubled with a simple amplifier.

2) You need a simple preamp made with an opamp that is not available in your country.

3) I do not know what the circuit will do so I don't know if you need a latch or a flip-flop.

Audioguru said:

1) You need a simple oscillator made with a 555 IC. It can directly drive a piezo ultrasonic transmitter. if the voltage is too low then it can be easily doubled with a simple amplifier.

2) You need a simple preamp made with an opamp that is not available in your country.

3) I do not know what the circuit will do so I don't know if you need a latch or a flip-flop.

Click to expand...

hmm ya at other end i need just an output to drive any latch or flip flop etc (as i did in previous circuits confirmed by the forum last year) . . and now i can apply amplification , credit goes to you

Matter is to design proper reception unit after 55 transmitter

& & &

One thing i want to ask that , there are so many 555 oscillator circuits available for driving IR LEDs with 40KHz
So are they all applicable for transmitter prupose by simply replacing LEDs with piezo TX or i need to make changes again ?????

please comment

rajaram04 said:

One thing i want to ask that , there are so many 555 oscillator circuits available for driving IR LEDs with 40KHz
So are they all applicable for transmitter prupose by simply replacing LEDs with piezo TX or i need to make changes again ?????

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Yes, you can use the normal oscillator circuit. If you Google ne555 calculator, you can find web pages that help you choose component values.

- Put a 470 Ohm resistor in series with the transducer.
- Take output from pin 3 of the 555 to the transducer.
- If you add another 555 configured as an inverter, you can get double the voltage on the transducer for longer range. Using an ne556 is a good idea. It is the same as two ne555s on one chip.

godfreyl said:

Yes, you can use the normal oscillator circuit. If you Google ne555 calculator, you can find web pages that help you choose component values.

- Put a 470 Ohm resistor in series with the transducer.
- Take output from pin 3 of the 555 to the transducer.
- If you add another 555 configured as an inverter, you can get double the voltage on the transducer for longer range. Using an ne556 is a good idea. It is the same as two ne555s on one chip.

Click to expand...

ya ya that i know about pin 3 of 555

but you told me about invertor above

so why only invertor for the voltage doubler ??

The trick is to connect the transducer between the outputs of the two 555s. Thus both ends of the transducer are driven with the same voltage, but with opposite polarity - when one end is plus, the other is minus and vice versa.

godfreyl said:

The trick is to connect the transducer between the outputs of the two 555s. Thus both ends of the transducer are driven with the same voltage, but with opposite polarity - when one end is plus, the other is minus and vice versa.

Click to expand...

hmm ya got the total point what actually it does . . thanks !!!