LM567 help need

[aruna1]

Hi
I'm working on a tone decoder for my ultrasonic receiver. my goal is to detect input signal and verify whether its 40kHz. I'm using LM567chip for this. circuit is tuned for 40kHz and measured at pin 5.

my problem is circuit isn't working as it should be (according to data sheet)


EDIT: please note in following diagrams C4 should be 0.02uF. I have incorrectly marked it as 0.001uF.


First attempt
This is the first circuit I tried



In this circuit LED does not light for the 40khz input signal. actually LED wont turn on what ever input it get.

Second attempt

Then my second attempt is disconnecting capacitor C1 from pin 1. then LED turned on dimly when there is no input and LED lights brightly when detecting 40kHz signal. this is the circuit




Third attempt

in my third attempt I connected 100k resistor from 5V to pin 1. after that LED is turned off when there is no 40khz input and LED turns on when detecting 40khz signal. but problem is now circuit responds to sounds other than 40khz signal.sounds like clapping and tapping sounds. when clapping LED blinks faintly.
here is the circuit


Forth attempt

here I connected both C1 and R3 as in data sheet but result is same as attempt 1. LED doesn't turn on with or without signal
this is the circuit



This is kind a funny. I cant figure out what the heck is wrong. first I thought LM567 was burned so I brought another but results are same.

can someone help me here? I'm pretty frustrated.
thank you

[MikeK]

You might need to run your numbers again.  I used this calculator: http://www.vk2zay.net/calculators/lm567.php with your values and got 181kHz with the pot at middle (5Kohm).

[aruna1]

oops sorry C4 is 0.02uF. I marked it in the above diagrams incorrectly. in actual circuit I have used 0.02uF as timing capacitor and it gives 40kHz when timing resistor is about 1.136k ohms.

as i said before I measured frequency at pin 5 and it is 40kHz.

[billhowl]

I think your C1 & C2 is too large, try C1 0.02uF, C2 0.01uF

[aruna1]

I think your C1 & C2 is too large, try C1 0.02uF, C2 0.01uF

nope that didnt work LED wont turn on with input of 40kHz