I was looking at a schematic today for a Top Card, trying to understand how the pop bumpers light up for 1000 pts - when they do and when they don't. It seems to depend on the I relay, whose state depends solely on the F relay:

TC I relay (resized).JPG

The F relay is a mini-stepper (00-90 relay). I can't understand from the schematic how it is supposed to fire. If the switches are as shown on the schematic when the game starts, then I can't see how the F relay is connected to anything. The relay chart lists the A relay as having 5A and 1B switches, which are all highlighted below. The A relay is an interlock relay, so should stay in one position once the game starts.

Does it make a connection through the L switch and the Thousands Unit Runout switch? Then it wouldn't make a connection if the 1000 score reel is at zero...that's kind of random. Were they going for some unpredictability? Am I just missing something obvious?

Thanks

TC F relay (resized).JPG

Thanks @sizteves: Except that that A switch is open during a game. It opens once the game reset is completed.

I guess I'm answering my own question here, but since the A switch never closes, the only option is that it's got to be getting a pulse to fire each time the L relay fires AND the 1000's unit runout switch is closed (so when the 1000 score reel is at any number other than zero). When the 1000 score reel is at zero, F doesn't fire.

Does that sound right to you smarter-than-me folks out there?

It looks like that's the only path, so that must be what's happening. Wonder why they wanted it not to fire when the 1000's reel was at zero....unpredictability?

Thanks Mark - I had forgotten that the F relay was used for the match function - so unpredictability was important. The whole reason I was wondering about it was that I was playing with the game with the glass off, using my finger to close switches and figure out the game rules - wanted to see if I could figure out what made the pop bumpers light or not...and it seemed to be somewhat unpredictable. I didn't know if it was a malfunction or not - but it looks like it's part of the intended design.

Good to know - thank you!!

Love Dangerous Dann's predictor too - hadn't seen that before.