Problem with output in IR led & tsop1738 circuit

[vicky29]

tsop1738 brasil

Hi friends,
I was just trying to study IR led and Sensor (tsop1738) somedays back i made this circuit, when i give power to IR led the output of tsop1738 goes low and when i removed power from led the output used to become high. but, today when i was trying to build the same circuit, the output remains high even if i give power to led or remove the power. i tried changing the components also.

Can someone please help me out in finding out my mistake.

Thanks.

 

[leomecma]

Re: IR led & tsop1738

Seemingly doesn't exist any mistake. Did you already change IR LED and the TSOP1738? Pay attention on max. current on IR LED.

 

[vicky29]

IR led & tsop1738

I've Tried changing each and every component. can u please suggest some other value for resistors.

thanks

 

[aProgrammer]

Re: IR led & tsop1738

This can't work because tsop1738
require (and only detect) a 38khz carrier,

so you need an 38khz oscillator to drive the ir led.

 

[vicky29]

IR led & tsop1738

hi aProgrammer
thanks for replying ...i know tsop1738
require a 38khz carrier but i hve done this before without any carrier and it did work out very properly...i used it in a small robot (for making its eyes).....

 

[ragabs]

IR led & tsop1738

i think the first step in any ir recievers is bpf with a specified center freq so i think that it will neglect low freq which u made by adding and removing power of the ir transmitter.