+ Post New Thread
Results 1 to 5 of 5
  1. #1
    Newbie level 4
    Points: 417, Level: 4

    Join Date
    Mar 2012
    Posts
    7
    Helped
    0 / 0
    Points
    417
    Level
    4

    How to improve the range of my IR transmitter built with HT12A

    I have made an IR transmitter with the help of HT12A and there is a decoder HT12D with a TSOP1738.Its range of working is only 1 ft i want to make it working like a TV remote which can work from a distance of 10m and they have decent directional angle also.
    I have worked on HT12E/HT12D it was much better and reliable.But I want to give my transmitter a remote feel that's why i shifted to HT12A for IR.But its range is a big problem.Please help


    •   Alt6th March 2012, 05:14

      advertising

        
       

  2. #2
    Advanced Member level 4
    Points: 7,022, Level: 19
    klystron's Avatar
    Join Date
    Jul 2002
    Location
    South Africa
    Posts
    1,013
    Helped
    188 / 188
    Points
    7,022
    Level
    19

    Re: How to improve the range of my IR transmitter built with HT12A

    Increase the TX IR LED current. (reduce R1 to 50 ohm, but first check the max. load current of the LED)



    •   Alt6th March 2012, 06:08

      advertising

        
       

  3. #3
    Member level 3
    Points: 683, Level: 5
    captainshahid's Avatar
    Join Date
    Feb 2012
    Location
    india, bhopal
    Posts
    59
    Helped
    8 / 8
    Points
    683
    Level
    5

    Re: How to improve the range of my IR transmitter built with HT12A

    increasing the LED current will increase the rate of intensity but it will affect the LED performance ....
    u should use the circuit like this 11.gif

    it is the best for your objective for both circuit safety and range.
    captain.........



    •   Alt6th March 2012, 06:29

      advertising

        
       

  4. #4
    Newbie level 4
    Points: 417, Level: 4

    Join Date
    Mar 2012
    Posts
    7
    Helped
    0 / 0
    Points
    417
    Level
    4

    Re: How to improve the range of my IR transmitter built with HT12A

    will it work for diverse directivity also.Apart from that do any one know how the TV remotes have such a good range



  5. #5
    Advanced Member level 5
    Points: 54,409, Level: 56
    tpetar's Avatar
    Join Date
    Sep 2010
    Location
    Pancevo, Serbia
    Posts
    6,468
    Helped
    1708 / 1708
    Points
    54,409
    Level
    56

    Re: How to improve the range of my IR transmitter built with HT12A

    What TX IR Led you using ?


    Use TSAL6400 5mm this led can go 100mA or 200mA in peak, I get with this led about 7m rc distance.

    What power source you using, I mean what battery ?

    With 330R resistor of IR LED :
    @5V you have 15mA for IR LED
    @3V you have 9mA for IR LED

    Decrese this resistor to value 100R and try, this will give 50mA @5V or 30R @3V to IR LED if battery allows.

    Check battery or replace it.

    You can use TSAL4400 3mm also.



+ Post New Thread
Please login