IR... What can be the Problem.

[Ayne]

Below is the circuit I have assembled.

I have done these checks.
1. I see my IR LEDs in Mobile camera... It was ON, when i Pull Down RST Pin Down to ground LED Became OFF. (It means 555 working fine)

2. I check the frequency of 555 on oscilloscope and set it to 38.05KHz.

My IR transmiting LEDs and receiver on the same PCB.

I put a mirror infront of Transmitter. IR waves are reflected back but IR receiver Data PIN is still to High. It is not going to LOW.

But when I Press My TV's(SONY) remote button infront of IR receiver The date PIN oscillate between HIGH and LOW.... (I think it is right condition cuz Remote sending codes High and LOW)

What can be the Problem why Receiver not detecting wave created by my transmitter.

 

[Leftyretro]

Below is the circuit I have assembled.

I have done these checks.
1. I see my IR LEDs in Mobile camera... It was ON, when i Pull Down RST Pin Down to ground LED Became OFF. (It means 555 working fine)

2. I check the frequency of 555 on oscilloscope and set it to 38.05KHz.

My IR transmiting LEDs and receiver on the same PCB.

I put a mirror infront of Transmitter. IR waves are reflected back but IR receiver Data PIN is still to High. It is not going to LOW.

But when I Press My TV's(SONY) remote button infront of IR receiver The date PIN oscillate between HIGH and LOW.... (I think it is right condition cuz Remote sending codes High and LOW)

What can be the Problem why Receiver not detecting wave created by my transmitter.

I suspect that your IR receiver is wanting the IR signal with a certain sort of duty cycle of pulses (pulse width) while your 555 probably is sending a 50% mark space ratio at the carrier frequency. I'm sure the data sheet for the IR reciever device should shed light onto the problem.

Lefty

 

[HarveyH42]

Why do you even need a 555? I did a similar project with an Attiny13, using the timer in the chip. Only got about a 12 inch range.

https://www.electro-tech-online.com/threads/pcb-considerations-with-microcontrollers.26039/

 

[audioguru]

Somebody else showed that "surplus" ZD-1952 IR receiver IC. The store that sells it (Jaycar in Australia) doesn't know who made it and doesn't know if it is 30kHz or 40kHz or any frequency in between.
Maybe those IR receivers don't work.

The datasheet for the receiver shows it receiving the carrier turning on and off at about 833 Hz. Maybe it won't receive a continuous carrier since it is designed to receive data.

 

[ikalogic]

Maybe it won't receive a continuous carrier since it is designed to receive data.

yes they are,, i worked with many similar IR receivers, and all of them were designed to receive low duty cycle signals, otherwize it doesn't work..

 

[audioguru]

yes they are,, i worked with many similar IR receivers, and all of them were designed to receive low duty cycle signals, otherwize it doesn't work..

This "no-name-brand" IR receiver's datasheet doesn't say so but Vishay's TSOP lines of IR receivers have AGC that turns down the gain if the IR is continuous to reduce its sensitivity to compact fluorescent light bulbs that operate at about 40kHz continuously.

 

[Gayan Soyza]

Hi ayne keep focusing your transmitting IR LED’s to the receiver & try adjusting the V/R slowly until you get an output in the receiver.(you better adjust the sending pulse between 30-40 KHz with a correct Duty Cycle) & check if still no output try & change your IR module(branded one).

 

[Roff]

I suspect that your IR receiver is wanting the IR signal with a certain sort of duty cycle of pulses (pulse width) while your 555 probably is sending a 50% mark space ratio at the carrier frequency. I'm sure the data sheet for the IR reciever device should shed light onto the problem.

Lefty

His 555 circuit cannot produce a 50% duty cycle. This will lower the sensitivity. Use one of the 555 circuits which will produce a 50% duty cycle, or, better yet, run the 555 at 2 times the receiver center frequency, and follow the 555 with a CD4013 D flip-flop configured to toggle (divide by 2). This way, you can adjust the frequency without screwing up the duty cycle.
EDIT: The only datasheet I could find (which Google points to, but the part number is not mentioned in the datasheet)
https://www.electro-tech-online.com/custompdfs/2007/03/ZD-1952.pdf
says data pulse widths need to be between 400 and 800usec, which seems to confirm what Audioguru said.

 

[Ayne]

One more thing. IR receiver which i have attached before, my ir looking like that, I don't know that it is really that IR which i have attached... But it is looking like that...

Originally Posted by audioguru
Maybe it won't receive a continuous carrier since it is designed to receive data.

May be, now i will try this..

I want to use this for Tachometer (Want to make Tachometer with PIC)..

 

[gramo]

I just tried to sim your circuit as requested in a PM

The counter is a frequency type, and appears laggy because of the sim time. There are 2 sims back to back, one for either end of the pot value

I'm not sure why you wanted me to do this as you used a cro to test the carrier wave as stated earlier;

I check the frequency of 555 on oscilloscope and set it to 38.05KHz.

Perhaps I'm using the wrong value component somewhere, but the results are not of that in your real life application

 

[gramo]

Forgot to link the file;

https://www.box.net/shared/e7ha3gvuhz

 

[Ayne]

I'm not sure why you wanted me to do this as you used a cro to test the carrier wave as stated earlier;

Because my friend was moving the pot for adjusting the frequency on digital oscilloscope (in college). I not set the frequency. Now I send u message cuz want to know that what is the Maximum and minimum frequency range that can be achived using POT....

One thing more after watching movie
On circuit Maker the range using the POT is 29.19KHz TO 46.51KHz...
But in UR protes it is about 17.12KHz TO 31.39KHz....


It means my circuit maker is better than ur simulator...
Thank u.
Thanks.

 

[gramo]

That or I have used a wrong component somewhere, I didn’t put my full attention into the model.

Edit, just re-sim'd the circuit, getting the following mins/max's (based on an vsm oscilloscope)

26.31
52.63

 

[Ayne]

Circuit is working.....

Maybe it won't receive a continuous carrier since it is designed to receive data.

Yes it is for receiving data.........I connect a pushbutton with IR transmitter(RST Pin) and an led with receiver... When i press Pushbutton LED connected to receiver blink....
Thanks....

 

[audioguru]

Circuit is working.....

What did you do to fix it?

 

[Ayne]

What did you do to fix it?

Nothing.
First i was sending countinous carrier(This was the problem)
Now i send data (just with pushbutton) and it is receiving data...

Thanks to all

 

[tanmay.dadheech]

i have a phototransistor L14F1, the package has 3 pins, one emitter , base and collector. where should i connect the base(or leave it unconnected), because i think the transistor will get the base drive through IR signals