IR sensors - Electronic Circuits Projects Diagrams Free

arien · 23rd September 2007, 01:50 PM

hi everyone..

we are currently doing a project on our electronic design subject. it is an automated light control system and we are using IR sensors for that. The project is working but the problem is that the range is too small. The transmitter and receiver works when they were 5cm apart only. can anyone recommend a long range(approx. 3 feet or more) pair of IR sensor with low biasing voltage? (9V) Please give the specific specs if you can. It will surely help us. Thanks a lot and God bless.

arien

audioguru · 23rd September 2007, 03:58 PM

Why not fix the circuit that you have?
Attach its schematic and parts list for us to see why its range is so small.

The range for most TV IR remote controls is 10m.

**Krumlink** · 23rd September 2007, 07:47 PM

They have such crazy range because they are blasted with around 1 amp of current so fast that it doesnt effect the LED much.

audioguru · 23rd September 2007, 10:28 PM

TV remotes use an IR receiver IC that has high gain. Its case rejects visible light. It has automatic gain control. It has a bandpass filter. It is smart.

penoy_balut · 24th September 2007, 02:00 AM

Quote:

Originally Posted by audioguru

TV remotes use an IR receiver IC that has high gain. Its case rejects visible light. It has automatic gain control. It has a bandpass filter. It is smart.

Agree.

I use TV IR TX/RX LEDs for my projects they are cheap, low power and long range. Data modulate the 38kHz driving IR transmitter, make your own communications protocol or use the popular RC5.

arien · 24th September 2007, 12:08 PM

Quote:

Why not fix the circuit that you have?
Attach its schematic and parts list for us to see why its range is so small.

The range for most TV IR remote controls is 10m.

attached here is the transmitter and receiver we have used.. the parts and components used were indicated.. please kindly check the circuit provided..
thanks a lot..

audioguru · 24th September 2007, 02:02 PM

The receiver doen't have an amplifier for the extremely weak signals from the IR diodes. The IR diodes are probably sensitive to visible light unless they have a black case.
No wonder the sensitivity is poor.

philba · 25th September 2007, 12:32 AM

agreed. use a modulated IR receiver like the 1138 from vishay (or similar). You will need to modulate the transmitter so it will require a second 555.

arien · 25th September 2007, 03:29 PM

Quote:

agreed. use a modulated IR receiver like the 1138 from vishay (or similar). You will need to modulate the transmitter so it will require a second 555.

How can we modulate the transmitter? How can we incorporate that to the present tx circuit? thanks a lot.

arien · 25th September 2007, 03:37 PM

Quote:

I use TV IR TX/RX LEDs for my projects they are cheap, low power and long range. Data modulate the 38kHz driving IR transmitter, make your own communications protocol or use the popular RC5.

RC5?.. microprocessor?.. sir,we don't have enough knowledge on microcontrollers..

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23rd September 2007, 01:50 PM	(permalink)
arien	IR sensors hi everyone.. we are currently doing a project on our electronic design subject. it is an automated light control system and we are using IR sensors for that. The project is working but the problem is that the range is too small. The transmitter and receiver works when they were 5cm apart only. can anyone recommend a long range(approx. 3 feet or more) pair of IR sensor with low biasing voltage? (9V) Please give the specific specs if you can. It will surely help us. Thanks a lot and God bless. arien

23rd September 2007, 03:58 PM	(permalink)
audioguru	Why not fix the circuit that you have? Attach its schematic and parts list for us to see why its range is so small. The range for most TV IR remote controls is 10m. __________________ Uncle $crooge

23rd September 2007, 07:47 PM	(permalink)
Krumlink	They have such crazy range because they are blasted with around 1 amp of current so fast that it doesnt effect the LED much. __________________ MechTronics World of Warcraft is a disease

23rd September 2007, 10:28 PM	(permalink)
audioguru	TV remotes use an IR receiver IC that has high gain. Its case rejects visible light. It has automatic gain control. It has a bandpass filter. It is smart. __________________ Uncle $crooge

24th September 2007, 02:02 PM	(permalink)
audioguru	The receiver doen't have an amplifier for the extremely weak signals from the IR diodes. The IR diodes are probably sensitive to visible light unless they have a black case. No wonder the sensitivity is poor. __________________ Uncle $crooge

25th September 2007, 12:32 AM	(permalink)
philba	agreed. use a modulated IR receiver like the 1138 from vishay (or similar). You will need to modulate the transmitter so it will require a second 555.