Baby Pac-Man uses an AS-2518-107 Lamp/Solenoid Driver Combo board instead of the usual driver boards found in other Bally solid states. This board has 14 soleonid driver circuits and 30 lamp driver circuits. It also contains the 5-Volt regulator and the flipper enable relay. To complicate things, the lamp drivers can control 2 lamps each, one on the "A" phase and the other on the "B" phase. I'm not exactly sure what this means, but I assume this refers to the AC voltage used to power the controlled lamps. Unlike other rectifier boards, the AS-2518-132 rectifier board used in this machine does not rectify the voltage used for the controlled lamps, so half work on the positive cycle of the AC voltage, and the other half work on the negative cycle.
The following table lists each driver transistor, the coil it drives,
the pre-driver IC associated with it along with the pin numbers of the base and collector (respectively),
and the decoder IC BINARY input signals (ABCD) and output pin number.
|Q31||#5 Drop Target, Right Side||U3, 16, 1||110/9|
|Q32||Not Used||U3, 10, 9||101/10|
|Q33||#3 Drop Target||U3, 11, 12||100/11|
|Q34||Not Used||U3, 13, 14||011/12|
|Q35||#1 Drop Target, Left side||U5, 16, 1||010/13|
|Q36||5 Drop Target Reset||U5, 6, 4||001/14|
|Q37||Outhole Kicker||U5, 8, 7||000/15|
|Q38||Right Maze Saucer||U5, 10, 9||n/a|
|Q39||Left Maze Saucer||U5, 11, 12||n/a|
|Q40||Flipper Enable Relay||U5, 13, 14||n/a|
"n/a" Decoder info indicates these drivers get their signals as continuous
solenoids directly from the MPU at A4J4-8, 9, and 10 and not the Decoder IC.
This table lists all the 2N5060 SCRs on the Lamp Driver module,
the name of the lamp it drives,
the decoder IC associated with the SCR along with the BINARY input signals (AD0, AD1, AD2, AD3) and output pin,
and the name of the 2K Ohm resistor (red/black/red) connected to the decoder output.
I got all this information from the schematics and pretty much copied it verbatim.
If you notice any mistakes (I'm only human), please let me know and I'll fix it up.
If you need to know which solenoid driver transistor goes to which solenoid driver board connector, Click Here.
If you need to know which lamp SCR goes to which lamp driver board connector, Click Here.
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