Circuit for IR sensor to read at <3cm distance (+10points

[koolslash]

ir sensor circuit

I want to make the IR receiver highly sensitive that i could detect the IR light across the DC motor DISC.distance between Tx-Rx will be <3m it will have to generate a pulse when a cycle is completed.

+10points will be awarded to a person who provide early exact solution.
i need it to implement and show on this Monday.

 

[FvM]

infrared sensor circuit

Apart from promising points (personally, I don't need it), you should primarly clarify the problem. The description is very vague.
E.g. DC motor DISC isn't a known technical term, I think.
And avoid cross postings.

 

[koolslash]

ir sensor circuits

Thanx for the advice. actually dont know which is the exact folder for this topic.

so the problem is:
i want to implement a feed back system which will read rotation of the the DC motor. now i m going to use IR-sensor. i need to know that what shall i do to make my IR-sensor working. i want to mount the transmitter and receiver across the GEAR or DISC mounted on the DC motor with a hole in it.
I want that when the Ir light passes through the hole of this gear/disc then the ir receiver shall generated a pulse.
distance between the transmitter & receiver is the main concern.(i want to make it that much sensitive).

 

[FvM]

distance sensor circuit

Normally, sender and receiver of a photointerrupter are mounted with a few mm distance. Operation is very easy and should work with any IR sensor type, without sensitivity issues. But I didn't understand if there are special constraints for your design.