Building a test set.

Ok, here is the rundown...

I have dozens of ticket dispensors at the FFC I work at. They are all made by Deltronic Labs. There are 4 pins on the mech. +12vdc, Gnd, Motor Enable (2-5vdc input from an external source, namely a game.) and the 4th pin is the 0vdc low, to 5vdc high notch count. Essentially the 4th pin produces a square wave. When the notch of a ticket encounters the opto 5vdc is present on the notch count pin, and then back to zero when opto is blocked by the rest of the ticket.

I've created a test set, that is simply a counter. the notch output from the ticket mech, is the input to 1 of 3 decimal counters, each decimal counter goes to it's respective 7 segment LED decoder, and then of course to a 7 segment LED to indicate ones, tens, and hundreds places.
The decoders have a lamp test feature (which I've utilized) and the decimal counters have a master set (did not utilize) and a master reset (take ground away and the couters reset to zero, I used a relay to do this since all I had was a normally open switch.)

The last thing on this circuit is another switch that sends 5vdc to the motor enable input of the ticket mech.

Anyhow the circuit works great. Here is what I want to accomplish on the next version.

I want to be able to set with toggles, a keypad or whatever (simpler the better.) to set how many tickets I want dispensed. Example, if I set the test set to 10, and then press a button that the motor enable turns on, and the ticket mech will dispense tickets, and when the test set counts 10 tickets the test set turns the motor enable off.

Game X does the same thing I want to simulate using the test set. The game needs to dispense tickets, it applies a 2-5 volts to the motor enable line, the motor turns, the tickets feed past the opto, and when the correct number of pulses are counted the game stops applying the 2-5 volts to the motor enable.

I hope that makes sense. Ideas and suggestions would be great.
Thanks.

The obvious solution is to use a micro-controller, or a micro-processor, or you could use a full computer to do it - hardware would be too limiting, and probably too expensive? (counting the development time).

Hello Freezerburn,

Since you have already created the first version of the test set, it would not be too difficult to improve it to the next version.

This time, instead of using normal up counters, use presettable decade up/down counters for your counting chain and use three thumb wheel switches for your preset input to these counter. You can keep the 7-Seg LEDs and decoders connected to the output of the counters. Wire the counters for count down operation.

To use it, set the number of tickets(say 123) via the thumb wheel switches and then "load" the counters. The LEDs would then display the initial count of 123. Applies the clocks to counter and watch the counts decreasing. When the display reaches zero, you can use an AND gate to detect this condition and control other parts of the motor circuit.