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Rationality in engineering

  1. Aug 12, 2010 #1
    I recently bought a toy with a remote control. The remote control consists of 2 LED lights and is powered by SIX AA batteries. Am I being naive to think that 6 AA batteries is overkill for powering 2 LED lights? The toy itself is a propellor-driven helicopter that only weighs a few ounces and runs on 2 AAs. Is there any rationality in this other than supporting AA battery sales?
  2. jcsd
  3. Aug 12, 2010 #2


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    Staff: Mentor

    Presumably, the remote control also includes a transmitter....
  4. Aug 13, 2010 #3
    I assumed the LEDs meant it was like a TV remote control, not a radio transmitter. Do you think it would have both?
  5. Aug 13, 2010 #4
    Well yeah... an LED won't fly the mini helecopter, so it needs a transmitter (and it'll have a frequency written on it somewhere). The reason you you so many batteries is the voltage output, radio transmitters are typically 9V.

    If you got 1 9volt battery that would do the trick, wouldn't last too long though. From that I suppose you could argue that it's keeping AA in sales. Just get rechargables.
  6. Aug 13, 2010 #5
    This is a very simple helicopter that just goes up and down. It's meant for indoor use. I think the LEDs are just infrareds that flash codes to an "eye" on the helicopter. I have other LED flashlights that run on 2 AAs. I'm not 100% sure it doesn't have a radio transmitter but I don't see the point. Why wouldn't a TV-type infrared LED remote be sufficient?
  7. Aug 13, 2010 #6
    Post a link to a similar type of helicopter please, without knowing what it is it's impossble to say. The pure fact it's 9V suggests a transmitter.

    Although there are two very very easy ways to test this.

    1.) Does the LED light up?
    2.) Try using the helicopter with the 'remote' not in line of sight or anything that IR can bounce off.
    Last edited: Aug 13, 2010
  8. Aug 13, 2010 #7
    Well, I haven't tried the thing out yet because I'm afraid of causing a global shortage of batteries if I do:)

    Actually, I went and actually read the package (imagine that) and it says "infrared control," but the reason it has so many batteries, it seems, is that the helicopter re-charges from the remote control. Sorry I didn't realize and say this earlier. It invalidates this entire thread actually.

    Apparently this toy is engineered quite cleverly to minimize vehicle weight. Praise to the engineers!
  9. Aug 13, 2010 #8


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    You read the product's specifications?!! Blasphemy! :rofl:
  10. Aug 13, 2010 #9
    I know. I cheated. I should have just kept staring at the device and pondering the magic of it all.
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