need of long range IR transmiter - Electronic Circuits Projects Diagrams Free

compass1982 · 2nd November 2006, 04:35 PM

hello everyone,
can anyone show me how to biuld a long range IR transmitter circuit (can be detected more than 20 centimetres from a IR detector). and any suggestion on the IR transmitter led? please help, i am stucked in he middle of my project

HarveyH42 · 2nd November 2006, 05:42 PM

We really need a lot more information. Can you post a diagram of what you've done so far? How much more than 20 cm? A TV remote is good for 15-20 feet. The IR laser diode from your slow-ass 4X CD burner might get you half a mile (and possiably do some permanent eye damage...).

Most IR LEDs put out plenty of light, just that it's not reflected well. Instead of potential eye damage, it would be better to work on the detection/reciever side.

audioguru · 2nd November 2006, 05:45 PM

If you are transmitting data, not voice or music, then why not use the simple IR transmitter circuit in a TV remote and a TSOP IR receiver IC? They have a range of about 10m.

**Nigel Goodwin** · 2nd November 2006, 06:49 PM

Quote:

Originally Posted by audioguru

If you are transmitting data, not voice or music, then why not use the simple IR transmitter circuit in a TV remote and a TSOP IR receiver IC? They have a range of about 10m.

Easily that, when I was testing my IR PIC tutorial circuits they worked fine the full length of the workshop at work, something like 18 metres?.

compass1982 · 3rd November 2006, 02:17 AM

this is the IR transmitter and receiver that i constructed:

Quote:

Originally Posted by audioguru

If you are transmitting data, not voice or music, then why not use the simple IR transmitter circuit in a TV remote and a TSOP IR receiver IC? They have a range of about 10m.

i am not transmitting data too, juz wanted to use the transmitter IR light to activate the receiver circuit. i found that this TSOP is good, can please provide the full circuit for me? thanks a lot

audioguru · 3rd November 2006, 02:31 AM

You don't have a current-limiting resistor in series with your IR LED. It will burn.

The TSOP1738 is a complete IR receiver. It needs only a 5V power supply. Get its datasheet from www.datasheetarchive.com .
Nigel also has them in his PIC tutorials.

compass1982 · 3rd November 2006, 02:56 AM

i have a question, based on the circuit that i constructed, is it possible to boost it so that the transmitting range becomes further?

audioguru · 3rd November 2006, 03:02 AM

Quote:

Originally Posted by compass1982

i have a question, based on the circuit that i constructed, is it possible to boost it so that the transmitting range becomes further?

Of course. Use a TSOP IR receiver IC for very long range. Your IR receiver circuit is just a single emitter follower transistor with hardly has any gain.

compass1982 · 3rd November 2006, 04:33 AM

are you saying that the problem that caused my IR circuit could not work in long range is because of my receiver circuit? so u suggest i replace the normal IR detector with TSOP into the circuit or only plug the IR to the PIC? sorry to bother as i am a noob in electronic stuff.

edited: is the TSOP compatible with other ordinary 2 pin IR transmitter ?

audioguru · 3rd November 2006, 01:44 PM

Yes, your receiver didn't have any gain. A TSOP receiver has lots of gain and many other features.
The TSOP is tuned to an IR carrier frequency. The TSOP1736 is tuned to 36kHz, the TSOP1738 is tuned to 38kHz and there are also other carrier frequencies available. Just tune the frequency of your 555 oscillator in your transmitter to the same matching frequency.

compass1982 · 3rd November 2006, 03:33 PM

thanks for the reply. TSOP 1738 is being tuned to 38kHz, meaning i must tune my 555 timer exactly 38kHz or is there any tolerance? can u show me the formula to tuned the 555 timer, as i wanted to compare with my formula. thank you

audioguru · 3rd November 2006, 03:52 PM

The datasheet for the TSOP IR receiver shows the width and tolerance of its bandpass, and the datasheet for the 555 shows the formula for its frequency.

I think the resistor values in your 555 oscillator are too low, and the capacitor's value is too high.
You should add a current-limiting resistor in series with the IR LED so that its current does not exceed the max spec'd on its datasheet.

compass1982 · 3rd November 2006, 05:02 PM

i have reconstructed the circuit, is the value of the resistors and the capacitor ok for this circuit?

philba · 3rd November 2006, 05:13 PM

your LED doesn't have a current limiting resistor. (hmm, seems like I've heard that before...). it's hard to say which will burn out first - the 555 or the LED. also, you left rst floating, no cap between con and gnd and no decoupling caps. other than that, it's fine.

look here for more info: http://www.doctronics.co.uk/555.htm#astable

compass1982 · 4th November 2006, 10:25 AM

regarding the TSOP1738, is it the receiver itself already capable to boost the range of 20 metres? or it need additional circuit to make this happen? can anyone show me the programming for this sensor? i am using PIC 16F877A? is the output of TSOP1738 measured by resistance or voltage?

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2nd November 2006, 04:35 PM	(permalink)
compass1982	need of long range IR transmiter hello everyone, can anyone show me how to biuld a long range IR transmitter circuit (can be detected more than 20 centimetres from a IR detector). and any suggestion on the IR transmitter led? please help, i am stucked in he middle of my project

2nd November 2006, 05:42 PM	(permalink)
HarveyH42	We really need a lot more information. Can you post a diagram of what you've done so far? How much more than 20 cm? A TV remote is good for 15-20 feet. The IR laser diode from your slow-ass 4X CD burner might get you half a mile (and possiably do some permanent eye damage...). Most IR LEDs put out plenty of light, just that it's not reflected well. Instead of potential eye damage, it would be better to work on the detection/reciever side.

3rd November 2006, 02:31 AM	(permalink)
audioguru	You don't have a current-limiting resistor in series with your IR LED. It will burn. The TSOP1738 is a complete IR receiver. It needs only a 5V power supply. Get its datasheet from www.datasheetarchive.com . Nigel also has them in his PIC tutorials. __________________ Uncle $crooge

3rd November 2006, 02:56 AM	(permalink)
compass1982	i have a question, based on the circuit that i constructed, is it possible to boost it so that the transmitting range becomes further?

3rd November 2006, 04:33 AM	(permalink)
compass1982	are you saying that the problem that caused my IR circuit could not work in long range is because of my receiver circuit? so u suggest i replace the normal IR detector with TSOP into the circuit or only plug the IR to the PIC? sorry to bother as i am a noob in electronic stuff. edited: is the TSOP compatible with other ordinary 2 pin IR transmitter ? Last edited by compass1982; 3rd November 2006 at 06:24 AM.

3rd November 2006, 01:44 PM	(permalink)
audioguru	Yes, your receiver didn't have any gain. A TSOP receiver has lots of gain and many other features. The TSOP is tuned to an IR carrier frequency. The TSOP1736 is tuned to 36kHz, the TSOP1738 is tuned to 38kHz and there are also other carrier frequencies available. Just tune the frequency of your 555 oscillator in your transmitter to the same matching frequency. __________________ Uncle $crooge

3rd November 2006, 03:33 PM	(permalink)
compass1982	thanks for the reply. TSOP 1738 is being tuned to 38kHz, meaning i must tune my 555 timer exactly 38kHz or is there any tolerance? can u show me the formula to tuned the 555 timer, as i wanted to compare with my formula. thank you

3rd November 2006, 03:52 PM	(permalink)
audioguru	The datasheet for the TSOP IR receiver shows the width and tolerance of its bandpass, and the datasheet for the 555 shows the formula for its frequency. I think the resistor values in your 555 oscillator are too low, and the capacitor's value is too high. You should add a current-limiting resistor in series with the IR LED so that its current does not exceed the max spec'd on its datasheet. __________________ Uncle $crooge

3rd November 2006, 05:13 PM	(permalink)
philba	your LED doesn't have a current limiting resistor. (hmm, seems like I've heard that before...). it's hard to say which will burn out first - the 555 or the LED. also, you left rst floating, no cap between con and gnd and no decoupling caps. other than that, it's fine. look here for more info: http://www.doctronics.co.uk/555.htm#astable

4th November 2006, 10:25 AM	(permalink)
compass1982	regarding the TSOP1738, is it the receiver itself already capable to boost the range of 20 metres? or it need additional circuit to make this happen? can anyone show me the programming for this sensor? i am using PIC 16F877A? is the output of TSOP1738 measured by resistance or voltage?