Learn more physics!
Q:
I have a plasma ball and also i have an infrared keyboard, tv remote, etc, when eva i turn on my plasma ball, these devices go mental, it is obvious that the plasma ball is giving off practically evert type of IR possible, is there any way of stopping this..?? (or narrowing the range of IR given off)
- Ross Gibson (age 17)
SOMERSET, ENGLAND
A:
You're right, remote controls give off infra-red (IR) light. But the
key thing to know is that remote controls have a very interesting way
of encoding the information it sends. That way, your tv knows what you
want it to do and your stereo doesn't pay attention. This usually
involves mixing the signal with a high frequency carrier that the
object on the other end can pick up the signal and ignore the rest of
the light. But in the end, your remotes send out pulses that represent
the 0's and 1's that electronics understand.
The problem with your plasma ball is that it sends out a lot of IR
light. It is not only the amount of light it sends out, but it also
sends out a wide range of pusle frequencies. This interfers with the
signal by adding in extra pulses and totally drowning out the signal
you want.
Adam
(published on 10/22/2007)
Follow-Up #1: Plasma Ball Confusion
Q:
In your answer to "Taming the Plasma Ball", you stated that IR is emitted in various frequencies that interfere with IR remotes & such. My question is if you had a plasme ball near your car alarm/lock, would it have any effect, & if not, why? Also would it effect your garage door if it was IR?
- Michael
Australia
A:
Michael -
Yes, the IR from your plasma ball could potentially affect even
those things if they were based on IR. But it's hard to say exactly
what the effects would be since the plasma ball basically sends out a
whole lot of IR on many different frequencies. Depending on the exact
frequencies that the car alarm, door remote, etc. use, it may or may
not interfere with them.
-Tamara
(published on 08/02/06)
Follow-up on this answer.
