Theatre Design & Technology - Summer 2019 - 45

ity for the possibility of overheating
and the dangers that are inherent with
low voltage devices. Be aware that the
heating coils can heat up to 350 to 375
degrees F. However, these coils are
also located within a metal chamber
surrounded by a glass chamber. This
tends to disperse the heat and allow
for a manageable, safe installation.
Vape pens also use a circuit to regulate
the voltage supplied by the included
12V-24V battery, although you would
not want to run that much voltage directly through your heating coil. Usually, between 3V and 6V is needed to
heat up the coils to produce smoke, but
the ultimate voltage is dependent upon
the heating coil included in the specific
device. We found that 4.5V, or three
AA batteries, in our system, produced
an adequate amount of smoke.
Voltage needed depends on resistance of Vaporizer Coil. The relationship between Voltage and Resistance
determines the amount of smoke produced, as well as what the safe rating
should be for cables and connectors.
OHMs law allows us to determine the
Wattage and Amperage of our device
based on variable Voltage and Resistance. The formulas are: Current
= Voltage/Resistance and Wattage =
(Voltage)^2 / Resistance. Most Vaporizers have heating coils between .5
and 2 Ohms of resistance. We are aiming for between 20 and 40 Watts worth
of smoke output. For our .5 Ohm coil
with a 4.5V battery, we are able to generate 40.5 Watts of smoke at 9 Amps.
With the continual air circulation over
our coil from the fan, we were able to
run a much hotter coil without burning
it out. Always turn on fan before applying power to heating coil.
We also found a trade-off between
voltage and longevity of the heating
coils and wicks. We found that the
lower the voltage, the longer the heating coils and wicks were able to last
before needing replacement. At 4.5V,
our device was able to last through
the entirely of tech before needing a
coil replaced and around three days
before needing a new wick. We ran
the device approximately one to two
hours a day total, with the longest time
being left on constantly at 20 minutes.
We had to refill the fluid in the device
once before afternoon rehearsal, once

before evening rehearsal during tech,
and once every three shows during
performance run. We were able to get
through a week of shows before needing to replace the wick. The second
heating coil lasted the entire two-week
run.
Technical Setup
The heating coil and glycol chamber of
our device was attached to the housing
of the vape pen unit. We disassembled
the rest of the device from the housing
and detached the positive and negative
leads from the battery and the circuit
board. Then we soldered wire extensions to the leads and connected them
to a small radio-controlled wireless
DMX dimming unit. For the input
voltage of 4.5V, three AA batteries in
a small pack were wired into the dimming unit. A small 6V brushless fan
was placed at the air intake of the vape
pen to push air backwards through the
system. It ran remarkably well underpowered, at 4.5V.
When using the remote dimmer
as a switch, be sure to proportion the
maximum output for the channel with
the Vaporizer to match what would be
needed for optimal smoke. For our .5
Ohm coil, we needed 4.5V so we profiled maximum output of our Dim B
channel to 37.5% of the 12V battery.
Within moments of being powered

Fogger and Fan

Vaporizer Unit with Fan

on, we were able to get reliable and
consistent smoke from the device. We
then secured the whole setup into the
trash can and controlled everything
from the lighting console. For our theatrical purposes, a 0% nicotine propylene glycol solution was used. We
also selected a neutral, vanilla scent to
minimize the distraction to the actors
and audience.
Overall, the project was a success.
Though there are dangers in working
with low-voltage in electronics, with
proper soldiering and by using the
correctly rated cable, hardware, and
installation and electrical insulation
techniques, one can minimize the risk
of electrical shock and fire.
Item

Total Cost

Electronic Vape Pen (2 coils
and 3 wicks included)

$30

Electronic Vape Fluid
(120 mL, more than needed
for the run)

$13

Tiny Brushless Fan

4.5 V Battery pack

TOTAL

$50

Note: The wireless remote-controlled DMX
dimmer was taken from stock, but could be
replaced by a few toggle switches for actor/
technician.

SUMMER 2019

THEATRE DESIGN & TECHNOLOGY

| 45

Theatre Design & Technology - Summer 2019

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