help me with this IR Transceiver

Status
Not open for further replies.
B

burhanmz

Member
i am making a IR transmitter receiver for audio signal, for home use

in the transmitter part i removed the transformer and the voltage divider circuit and made the rest as such.. it works giving me 240mA for the IR LEDs from 12 volts regulated supply

in the receiver part, i used a BD139 instead of BEL187, and BC548 instead of BC549. the rest of the circuit is as such..

both the circuits work.. i tested them.. but the problem is the the range is no more than 6 cm.. and i getting a very low volume of sound at the receiving end...
whats wrong with it.. how can i increase the range as well as the amplification of the received signal?
 

Attachments

  • receiver.JPG
    46.8 KB · Views: 141
  • transmitter.JPG
    49.9 KB · Views: 138
Sorry, but the entire thing is absolutely rubbish - it pops up here time and time again, and never works - for one thing the transmitter rectifies the incoming audio!.
 
but if it were rectifying the signal... then i shouldn't get any audio on the receiver end .. but thats not so. i am getting a very low audio signal..
 
in my first post, when said i had removed the voltage divider, i forgot to mention that i fixed biased it with 2.2kohms at Rb and connected parallel to Rc of 100ohms..

but my problem isn't the transmitter .. its the receiver...
 
Then check it with a scope, but there's really not a great deal of gain in the receiver, and the transmitter doesn't provide very much output as it's continuous carrier, so you can't pulse the LED's at high current like remote controls do.
 
thats exactly wht i am asking... how to increase the gain of the receiver... because when i tried to use a pre-amp audio amplifier with TDA2030, the signal stays as such,, but it works on other direct audio signals.
 
burhanmz said:
thats exactly wht i am asking... how to increase the gain of the receiver... because when i tried to use a pre-amp audio amplifier with TDA2030, the signal stays as such,, but it works on other direct audio signals.
Click to expand...

First find out where you're lacking, you need a scope to do that.
 
how about if i use a 555 as a VCO at transmitting and receiving ... with carrier frequency.. so that the audio is frequency modulated.. i can then control the duty cycle,.... would it work then?
 
burhanmz said:
how about if i use a 555 as a VCO at transmitting and receiving ... with carrier frequency.. so that the audio is frequency modulated.. i can then control the duty cycle,.... would it work then?
Click to expand...

A 555 is a pretty poor VCO anyway, and you're indroducing further complications.

If you want to go FM, then look at the 4046 PLL chip, a much better VCO in that.
 
thanks for the suggestion.. i'll try it first then if the results are satisfying, i'll post the improved circuit diagram..
 
Status
Not open for further replies.

Similar threads

E
  • Question
Help with my project please
Replies
13
Views
3K
danadak
S
  • Question
Need help with spst toggle to momentary
Replies
5
Views
1K
crutschow
S
  • Solved
Help with bus dash project
Replies
3
Views
2K
Stefan22
S
  • Question
Help with boost converter circuit
2
Replies
25
Views
3K
audioguru
S
  • Question
Need help with guitar pedal
Replies
7
Views
1K
ZipZapOuch
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…