R/C-operated Switch

Discussion in 'The Projects Forum' started by markosillypig, Oct 13, 2008.

  1. markosillypig

    Thread Starter Active Member

    Jul 21, 2008
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    hi all
    i have looked all over the net for a diagram of a circuit to turn the landing lights on and off my remote control airoplane.
    i only need 2 led's to switch on and off via a spare servo conector on the r/c reciever has any one got any idea what woyld be the best circuit to use as the power consumption is low.
    i have posted a diagram could anyone simplfy it
     
  2. mik3

    Senior Member

    Feb 4, 2008
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    Do you want the leds to flash or just turn on and after a while turn them off?
     
  3. markosillypig

    Thread Starter Active Member

    Jul 21, 2008
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    hi
    i just want the led's to turn on and off
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    What is the nature of the signal you would be working with? What does a CD4013 dual flip flop have to do with anything?
     
  5. mik3

    Senior Member

    Feb 4, 2008
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    If you just want the leds to turn on and after a while off you can use a transistor to drive them. If your button on the control is a push button the you have to use a thyristor as to keep them on until you press the button again or whatever and reset the thyristor with a transistor. Instead of using thyristor-transistor you can use a single RS flip flop and not this big circuit you designed.
     
  6. vetterick

    Active Member

    Aug 11, 2008
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    you can use the low tech approach, have a servo turn a swicth on/off,
     
  7. markosillypig

    Thread Starter Active Member

    Jul 21, 2008
    184
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    hi
    what would be the best circuit and what transistor would be the best to use
    thanx
     
  8. mik3

    Senior Member

    Feb 4, 2008
    4,846
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    Without knowing about the characteristics of the R/C spare output voltage/current rates and the operating voltage of the overall circuit (which i guess is not over 30V) a BFY51 transistor would be fine. If you want you can tell us more information about your circuit to help more.
     
  9. markosillypig

    Thread Starter Active Member

    Jul 21, 2008
    184
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    here is a small diagram of what i am wanting to make
    its simple i think. The vcc signal to is to operate a transistor on the board witch inturn will switch the led on
    hope this helps
     
  10. mik3

    Senior Member

    Feb 4, 2008
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    Can you post the current and voltage ratings of each led?

    Whats the voltage of your signal?
     
  11. markosillypig

    Thread Starter Active Member

    Jul 21, 2008
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    the signal is 3 volts
    the led's are fv 2.8v 20ma
     
  12. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Use a BC108 transistor, connect its emitter to ground, connect a 2.2K resistor on its base and then to the signal and then connect the cathodes of the two leds on its collector and use a 100ohm resistor for each led to connect it to 4.8 volts.
     
  13. markosillypig

    Thread Starter Active Member

    Jul 21, 2008
    184
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    hi i have just discovered that the signal output is a square wave oscillator, pumping out a series of variable 1mS - 2mS pulses over a 20mS frame rate can any one help with this circuit
    ps is there an alternative to a tip122 for up to 100ma
    thanks
     
    Last edited: Oct 20, 2008
  14. mik3

    Senior Member

    Feb 4, 2008
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    If you are going to drive the led with these pulses then its ok because it pulsates fast enough for your eyes to see that it blinks. The only think you will see is just the led to be continuously on (in reality it will pulsate) because of a phenomenon called the persistence of vision. Check my spectrum analyzer here

    http://www.youtube.com/watch?v=j-4h3l9O4fc

    actually one column only is turned on each time, but because they get refreshed fast you see them as to be turned on all the time. This is to convince that it works.
     
  15. karthik_dm

    Member

    Oct 16, 2008
    27
    0
    ---------------
    it think this design may satisfy u....connect this circuit to the output of your RF remote reciever...the leds start blink when the signal is recieved.
     
  16. karthik_dm

    Member

    Oct 16, 2008
    27
    0
    try this low volt led flasher
     
  17. markosillypig

    Thread Starter Active Member

    Jul 21, 2008
    184
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    hi but sorry but the voltage has to be 4.8 volts :)
     
  18. mik3

    Senior Member

    Feb 4, 2008
    4,846
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    At the end what do you want the leds to do, flashing or just turn on?
     
  19. karthik_dm

    Member

    Oct 16, 2008
    27
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    the circuit will work fine for 4.8 volts too....:cool: but you have to lower the series resistor value for LEDs. you just match its value by trial and error method....how ever try this 3v(work fine for 4.8v too)circuit with modification of previously posted one(my design.jpg)
     
  20. markosillypig

    Thread Starter Active Member

    Jul 21, 2008
    184
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    i would like the led's to just turn on
     
    Last edited: Oct 24, 2008
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