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ahonda55
Apprentice
Egypt
57 Posts |
 Posted - Dec 27 2009 : 5:08:55 PM
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Hello, i need to build an infra red circuit, but a bit long range, say 10 meteres.
I know that pulsing increases the IR range, but, my big problem is the receiver..
How can i build a circuit to "read" a specific frequency??
Is it a matter of a photo transistor which receives only one frequency??
I have tried an IR LED and IR transistor from an old PC mouse, but i only get about 30cm range!!
I just need a very basic circuit, but about 10 or even 5 meteres range.
Thanks a lot in advance :)
Ahmed |
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Dec 28 2009 : 12:44:57 PM
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Use an IR receiver IC. They are made to receive certain frequencies. That is what TVs, CD plyers and DVD players use so that their range is 15m. They have very high gain when the input is pulses in bursts of data. The gain is reduced when they receive continuous pulsing IR from compact fluorescent light bulbs.
Download Attachment:  TSOP IR receiver.PNG
29.04 KB
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ahonda55
Apprentice
Egypt
57 Posts |
Posted - Dec 28 2009 : 5:00:58 PM
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Many thanks, but i could not find this part here in Egypt, so i got a regular IR transistor and IR LED, to build this circuit
http://www.aaroncake.net/circuits/irremote.asp br / " target="_blank">Many thanks, but i could not find this part here in Egypt, so i got a regular IR transistor and IR LED, to build thic circuit br / http://www.aaroncake.net/circuits/irremote.asp br /
but i have some questions..
can i use a BC324 instead of the 2n2907?
can i use one comparator from LM324 instead of the 308?
how can i build the transmitter using an NE555 astable timer? i mean values for R1,R2 and C1 of the timer circuit.
and, what frequency does this circuit work at?
I am so sorry for asking so many questions :)
Greetings
Ahmed
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audioguru
Nobel Prize Winner
Canada
4218 Posts |
Posted - Dec 28 2009 : 9:05:01 PM
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The simple project has errors. It is not only IR since it is also affected by visible light.
A BC324 is an extremely old NPN transistor. You need a PNP transistor.
An LM324 is a quad opamp, not comparator. It has poor high frequency response. Any opamp will work but needs a resistor from its input to ground.
Use a 555 for the transmitter if you want.
The frequency is adjustable to whatever frequency you like. |
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ahonda55
Apprentice
Egypt
57 Posts |
Posted - Dec 30 2009 : 4:37:32 PM
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| Thanks a lot :) |
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IR basic circuit help
