To increase range...

[surjo_dm]

hello everyone,
In my recent project (for proximity detection), i use an IR LED for transmitting IR rays at 1khz and the rays when reflected from any obstacle is received by a sensor unit(GP1U26R). However, the range of detection is very low. For instance, the entire unit can sense a waving hand or a wooden ruler only to a maximum distance of 5 inches. Is there anyway by which i can increase the range of the unit?
Well, the receiver unit works fine and can sense a high freq. IR signal from few meters away. But what should i do with the IR LED (Transmitting part). Will it do any better if i increase the frequence of transmission. I am not sure :? and would definately like ur assistance.
Thank u once again,
surya

 

[Nigel Goodwin]

hello everyone,
In my recent project (for proximity detection), i use an IR LED for transmitting IR rays at 1khz and the rays when reflected from any obstacle is received by a sensor unit(GP1U26R). However, the range of detection is very low. For instance, the entire unit can sense a waving hand or a wooden ruler only to a maximum distance of 5 inches. Is there anyway by which i can increase the range of the unit?
Well, the receiver unit works fine and can sense a high freq. IR signal from few meters away. But what should i do with the IR LED (Transmitting part). Will it do any better if i increase the frequence of transmission. I am not sure :? and would definately like ur assistance.
Thank u once again,
surya

The range is severely limited by the reflective capabilities of the obstacles, if the obstacles are mirrors (correctly aligned) the range will be greatly increased (probably 20-30 feet, with enough power). Most of the obstacles you are likely to come across will be very poor reflectors of IR.

However, using a 1KHz modulation frequency sounds way too low for most IR receivers, I don't know the spec on this particular one, but they are usually around 38KHz.

What are you actually trying to use the proximity detector for? - they are commonly used in small robots, and the range is as great as it needs to be. For this reason the output power to the LED's is usually very low, increasing this will increase range - but will still be limited by the reflective properties of the objects