Techno Stuff
How They Work - Reflex unit

Almost all of the bingo machines have a reflex unit. Some of the mystic line games have two of them. The purpose of this unit is straightforward, it makes the game tighter after credits have been won.

If you are one of those happy/positive people, I guess we can say it makes the game more liberal if nobody has won anything for a while.

How it does this is very simple. As the game is racking up credits on the replay register, it is also stepping up the reflex unit. Wipers on the reflex unit rotate off contacts, thus breaking circuits.

As people play off credits or deposit coins, the reflex unit is stepped down, and eventually the wipers reconnect circuits.


We're going to dissect a reflex unit from a bally big time - mainly because I had a parts head so I could rip the thing out and take it apart without worrying where I put all the pieces.

If you've looked at some of the other sections in the "how they work" area, you are no doubt expecting to be bombarded with poorly explained circuit diagrams and incomprehensible tables of odds calculations. Since I'd hate to disappoint, here we go!

big time
reflex schematic
This hunk of the schematic is part of the circuitry used by just about everything that matters when you are feeding coins/credits into the machine. The green wire is the 50V power, and you want it on the purple wire. No 50V on the purple wire, no score/feature advance or extra balls.

Mixer #1 is covered in another section of the site, but the executive summary is that the rotor on mixer #1 can stop in 1 of 24 positions. Depending on where it stops, it may connect the green wire to one of the blue wires, or directly to the purple wire.

The reflex unit can be connecting the purple wire to any/all of the wires entering into it on the left side. The more wires the reflex unit is connecting, the better your chances are that the green wire will connect to the purple wire.