Star Tech Journal

Betson Big Choice
Voltage Spikes
Frank 'The Crank" Seninsky
Alpha-Omega Amusements & Sales
Edison, New Jersey
Figure 1
Dear Frank,
I own about 15 Big Choice cranes with the new
MPU boards, the ones that make sound. The
problems I am having are too numerous to list.
They range from giving 80 credits for a quarter to
constantfailure of the motor relays. I have about
4 of the older Big Choice's left that I have veryfew
problems with. ..
I would like to know if you have written any new
articles or have any modifications for this crane ...
any help at all would be better than what we get
from our distributor. Thank you. Fred Thornbury,
West Coast Video Games, Riverside, CA.
Dear Fred,
I have encountered this problem a few years ago
and have followed the advice of Betson's Senior
Engineer, Bill Seibert. Your problem is caused
by voltage spikes or noise that is induced by the
electromagnetic field surrounding the crane
motors. The voltage spikes are being transmit-
ted to the logic board and causing you the many
weird problems that you mentioned. Check to
see if any of the metal parts of the motor assem-
bly are magnetized. If they are try the following:
SOLUTION
The quick and easy solution is to run a wire from
any one of the black common ground mi-
croswitches to the metal frame that houses the
motors. I would run a wire from a second
microswitch just in case one of the wires does
not make a good connection. In effect, you are
connecting the whole metal frame assembly to
logic ground and getting rid of the voltage
spikes.
These problems do not occur with the cranes
using the old logic boards because there wasn't
enough electronic logic present on the boards
(relays were used).
Figure 3