BSR Whac-a-Mole, Owner'S Manual

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Bob's Space Racers
®
Whac-A-Mole
®
Arcade Games
26
WHAC-A-MOLE BOX
Over the years there have been improvements made to the Mole Box in reliability and longevity.
The original versions used two (2) switches wired in series. One switch located under the Mole
(a normally open switch) which would close when the Mole was hit. The other switch located
under the guide pin (a normally closed switch) which would open when the air cylinder was
down. The circuit for the two switches was fairly simple. The only time a player could score
was when the air had filled the cylinder (the bottom switch is now closed), and the player hit the
raised Mole (closing the top switch) thus completed the circuit through both switches.
The main problem with this design was that there are many parts associated with mounting a
switch. Often when a repair is done, parts were left off. The wires going to the switches had a
tendency to break, which caused the Mole to score all of the time or not at all. The parts that
prevented this are crimp terminals with a strain relief on the wire and a cable clamp to strain
relief the wire by attaching the wire to the switch housing.
The current version looks very similar, but the operation is quite different. Instead of two
switches, we now use an air switch under the Mole heads and an air pressure sensing switch that
senses when the Mole has been hit. This system uses the air that fills the air cylinder and we
plumb it into an air switch that is located under the Mole body. With the cylinder up, there is air
pressure on one side of the switch. When the Mole is hit the switch will open and allow air to
pass through the switch and down to a manifold. All of the switches are connected to this
manifold which, in turn, is connected to the air pressure sensing switch. The air pressure pulse
will pass down from the manifold to the sensing switch. Once the switch has an air pressure
pulse it will make an internal switch closure and will cause an input to activate on the processor
board.
With either set-up there is a rubber gasket on both sides of the switch (under the head) and these
parts are sandwiched between a metal plate on the outside and the Mole bracket on the other
side. The fastening nuts are 6/32 shake-proof nuts. This allows you to only snug the nuts instead
of pressurizing the switch, thus providing a shock mount for the switch.