Combinational Conjuring Trick
Combinational Conjuring
Rev. Thomas Scarborough
E-mail scarboro@iafrica.com
The simple circuit of Fig.1 emulates a similar conjuring trick which sells for hundreds
of Pounds. The trick seems to do the almost-impossible from an
electronic point of view, let alone from the point of view of common
sense.
It consists of a bank of three on-off switches (S19-S21), which have three switch
covers, each of a different colour. These switch a bank of three
lightbulbs (LP1-LP3), each of a different colour. The colours of the
lightbulbs correspond with the colours of the switch covers.
Now comes the interesting part. The switch covers may be exchanged at will, but
still they switch the lightbulbs of corresponding colour. Similarly,
the lightbulbs may be exchanged at will, but still they respond to
the switches of corresponding colour. On the surface of it, there
would seem to be 64 possible connections between switches and
lighbulbs, and no possible way that the conjurer can manipulate them
all.
However, add some
sleight-of-hand, and things become a lot simpler. Each switch cover
is symmetrical, in such a way that it looks the same whether facing
N, E, or W. Further, each lightbulb is screwed into a circular base,
which looks the same whether facing N, E, or W.
Let us consider just
one of the switch covers (S19). Three reed switches (S10-S12) are
positioned beneath the cover, at positions N, E, and W, and each of
these activates a different
lightbulb. Any one of the three reed switches may be closed by a
single magnet positioned strategically under the switch cover.
Depending on the orientation of the switch cover, therefore, the
switch will activate any one of the three reed switches, and thus the
selected lightbulb.
On discussing this
with an accomplished magician, the author was told that this alone
would be sufficient for the full effect described - reed switches
S1-S9 may be omitted. Nevertheless, the lightbulbs may similarly be
surrounded with three reed switches each, which are activated by the
orientation of the circular base - a magnet being strategically
positioned within it. These reed switches may thus reroute the power
to the conjurer's selected lightbulb.
There is just one
caveat from an electronic point of view. Carefully consider the
voltage and power ratings of the reed switches and on-off switches,
to match these with the chosen lightbulbs. Failing this, your trick
may demonstrate how none of the switches will activate none of the
lightbulbs.
