increasing range of ir

[addyismad]

hi guys,
i made a ir based sensor module....
the receivers resistance decreases on reception of ir.
i m then comparing the voltage across the receiver and getting digital outputs.
it works pretty fine for a range of sa 10cms....
i want to increase the range to about 1m or so....
suggest some way out.

 

[mstechca]

I'm sure your infrared part is either a photodiode or a phototransistor.

Like any load, it has more power if the resistance between the power source and the load is reduced.

A load can be either an input or an output device. It just consumes power from the power source.

So if your circuit has a resistor in series with your infrared part, reduce the resistor, but don't reduce it too much or your infrared part might blow up.

If that doesn't work, try adding an amplifier circuit to the output of the infrared unit.

 

[addyismad]

hi there,
yes i am using kinda photo diode only and increasing current ll increase range.
i kept on reducing range and used 47ohm only{.25 watts} resistor b/w source{5v} and the ir transmitter.
reducing it further ll make the led become alarmingly hot...
see even after reducing the resistor, i ll gain not tat much in distance, it hrdly gives a boost of just a few cms...
i want it to increase from 10 cm to about 1m atleast.
suggest some other gud options please...

 

[bloody-orc]

feed your led with high freq pulses so you can give it more curred so it will be brighter but wil not overheat. if using pic with PWM output, you can use this. if not use 555 for the jub. try to get about 40kHz out of it.