infrared remote

Discussion in 'Homework Help' started by majoka, Sep 10, 2009.

  1. majoka

    Thread Starter New Member

    Sep 10, 2009
    hi to everyone i want to make a ir remote just like a tv but i want to send my own data . i got help from net and try circuit on this link " " now after some trouble i succeed bt still hav a small range now can anyone help me that how can i increased my remote range. tv remote hav a lot of range with in a room and ir recieve recieved it from any direction with in a room and operate on 3 volt only what is a science in ir tv remote that only 3 volt give a room range
    kindly help me i have need it urgent ......
  2. Gustav180


    Aug 25, 2009
    Hello majoka
    To increase the range, you have to increase the power from the IR-LED:s. Important is also that the IR- transmitter and IR- reciever wavelength are the same.

    But the way to transmitt decribed at the site is not very efficient. It is enough to send a short puls for every positive and negative flank. This pulse can have a very high effect, the IR-LED can bee driven with several 10 mA:s. I don´t know if you can use the same reciever or you must design an own.

  3. majoka

    Thread Starter New Member

    Sep 10, 2009
    i am using the same reciever and also try on tsop1738 but behavior is same i think that problem is on emitter side i used normal ir led can u hav any schematic to solve this prblm........
  4. StayatHomeElectronics

    Well-Known Member

    Sep 25, 2008
    Have you tried using tip #2 at the end of the article you linked?

  5. majoka

    Thread Starter New Member

    Sep 10, 2009
    can u have a knowledge that how a tv remote transmit high power with just 3 volts its seem's to strange
  6. beenthere

    Retired Moderator

    Apr 20, 2004
    The output is an IRLED. Vf is on the order of 1.5 volts, so there is adequate capacity for current through the IRLED to make it emit.
  7. Papabravo


    Feb 24, 2006
    By reducing the size of the resistor in series with the IR LED, high PEAK currents can be achieved. A pulsed current of 300 mA would not be uncommon.
    Code ( (Unknown Language)):
    2. (3.3V - 1.5V) / .3 = 6 Ohms
    At a 10% duty cycle the average current would be 30 mA for part of the time it takes to send a command. This further reduces the current draw as seen by the battery.
  8. majoka

    Thread Starter New Member

    Sep 10, 2009
    i change the duty cycle from 50% to 25% and i get a suitable range almost near to tv remote thanx to all dears