Star Tech Journal

STAR*TEcH
Journal
June 1996
CID
SEGA PINBALL NEW FLIPPER DESIGN
... why con't o flipper coi\ be flipped
or energized \ike any other coi\?
It can, it should ... and now it is!
NEW FLIPPER DESIGN - NO FLIPPER BOARD!
Team Sega
Joe Blackwell, Eric Winston,
Ted Kilpin &Jay Alfer
Sega Pinball
Melrose Park, Illinois
One of the objectives in going to
the White Star Board System®
was to simplify the system for the
Operator. We have taken this line
of thinking one step farther by
simplifying our flipper circuit.
Our pinballs were the first to uti-
lize a Solid State Flipper System.
This required more complex cir-
cuitry in the form of the Solid
State Flipper Board but reduced
the overall amount of service
calls on the pinball by a good
25% due to increased reliability.
The White Star Board System
has allowed us to simplify the flip-
per circuit to the point where we
have eliminated the flipper board
altogether. The flipper circuit is
now configured the same as any
other solenoid drive circuit (see
illustration at right).
TECHNICAL OVERVIEW
Our New Flipper System uses
one supply voltage (50v DC) for
both kick and hold. Once the
Game CPU detects a flipper
cabinet switch closure ( during
game play) it applies a 40 msec
pulse to the gate of the flipper
drive transistor (STP20N10L). If
it continues to detect a flipper
cabinet switch closure (the player
holding the button in) it will con-
tinue to pulse the flipper drive
transistor 1 msec every 12 msecs
for the duration of the hold cycle.
The E.O.S. (End-Of-Stroke)
Switch serves the same function
as before as it prevents foldback A
when the player has the flipper W,
energized to capture balls. The
E.O.S. Switch is a normally
closed switch which opens ap-
proximately a 1/16" when the
flipper is energized. The Game
CPU will detect a switch closure
if the flipper bat is forced back
by a high velocity shot or re-
bound on the playfield and will
apply another 40 msec pulse of
50v DC to the coil.