|
Shown is a 120V, 4 Pole, Double
Throw, KH style or "Ice Cube"
relay. Nicknamed that since these
relays are always covered with
clear shells so you can actually
see inside. That must be for geeks
like me that have to see it before
I can understand it. I work with
these as they are readily available
from surplus places such as
All Electronics for just a few
bucks. Ice cube relays come in
different volts and amps, so be
certain about your needs before
choosing the one you will work
with.
First we need to
understand exactly what this little
goodie does. In some cases we want
to trigger something that is merely
closing a circuit and is passive
where it isn't actually sending 110
volts through the circuit, but
connecting two points to complete a
circuit which is sensed by the
device we are trying to trigger.
When the ice cube relay is hooked
up to 110V in this case anyway, it opens
and closes a host of points inside
the cube which can open or close
the circuit on your device if
hooked up to the proper two leads.
This relay is a 4 Pole,
 so
it has 4 circuits that it closes
when energized and also features 4
other circuits that remain closed
until that time. More on that
next. There are lots of examples,
but here I am going to use a fog
machine as was just one of the many
devices that was used on the single
relay shown in the top photo here
in the
Electrocution. This one relay
was employed to activate the voice,
another activated a fog machine,
and
finally the last two activating two Vari-Pet Timers from Cowlacious
Designs for two independent
animations. In this case I used a
power strip to trigger the relay
along with numerous other 110V
devices.
So using the fog machine as an
example of just how this works, you
should get a pretty good idea how
to use this for the other items
which are triggered by passively
connecting a single circuit. In
this photo you can see the wired
hand
 held
remote control with a switch in the
middle. Since I need so many items
to go off at the same time with
this prop it isn't practical to try
to do it by hand, hence the reason
for the conversion.
I open the switch box up and test
the two leads connected to the
switch to see if they carry current
 while
the circuit is closed ("closed"
meaning when the circuit or wire is
fully connected in a continuous
manner with no breaks as it would
have when the switch is not being
depressed) using a 110 V meter.
Since I determined that it is
indeed a passive circuit, I
 simply
solder a remote wire to each lead
of the switch legs (I could
eliminate the switch or just leave
it there and not worry about it,
depending on my future plans for
that remote control). The other
ends of the wire will now go to the
relay and when activated, the
readied fogger will emit fog.
The relay, as seen from an aerial
view as shown in this schematic,
has numerous rows of connecting
posts. On this particular relay,
the second row and bottom row are
the posts where you can connect one
wire to each which are "normally
open", meaning they are keeping the
circuit from connecting. Once power
is applied to the relay, 4 points
inside connect 4 different
circuits. In this case these 4
circuits are; 5 & 9, 6 & 10, 7 & 11
and 8 & 12. These are isolated from
each other, so there is no
possibility of one device bleeding
into the circuit of the next.
Next we have the top row and the
bottom row which are "normally
closed" which means two wires
hooked to the 1 & 9 legs would have
a complete circuit when the power
if off to the relay. And sometimes
you want the circuit to remain in
effect until the moment something
else is activated. An example of
that would be the Dr. Jekyll / Mr.
Hyde illusion using a two way
mirror and lighting to make the
person's face peering into the
mirror turn into a monster. The
other circuits here are 2 & 10, 3 &
11 and 4 & 12.
So what if you have a relay but it
is different from this 4 pole unit,
how can you find out which points
close which circuits? Use a
continuity tester as shown here.
This unit is similar to the volt
meter I used earlier, but different
in as much as it actually sends out
a low voltage DC current down the
line and allows a person to see if
two legs are open or closed as the
relay is activated and
un-activated. When the little light
inside the meter appears, you have
a closed circuit. Be sure you are
using a relay that only closes two
passive points inside each circuit
and does send out any current of
it's own. Electricity can kill if
mishandled.
Finally we hook up the relay to a
standard power cord to enable
activation
 of
it and consequently our fog
machine. Pick up a multi outlet
extension cord for about .70 cents
at WalMart or elsewhere and lose
the female gang end. Solder each
leg to the two bottom posts for
your power in. The post on the
relay directly between these two
points is a threaded ground which I
do not bother with myself. Now you
have the elements of a remotely
controlled event! By plugging this
in to a wireless remote base unit,
you can now set off your fogger, a
voice to a monster or an
elaborately timed animatronic from
anywhere in your haunt or yard!
Once I get my relay
set up the way I am happy with in
my props I then coat the entire top
of the exposed posts and wires with
hot glue until they are completely
covered and cannot shock me while
handling the event while plugged
in. For a deeper look into using
this relay for more items look at
the how-to
Motion Trigger. |
