I need a simple easy to build circiut for a coin credit board

[asreafkaudeer]

Hi, I have a video game cabinet which i cannot increase the credit setting on the main board, Its last setting is 3 coins 1 play. I would like to make it 4 coins 1 play. I need help to design an electronic credit board to put between the coin aceptor and the main board in order to increase the amount of coins. Please help any1. that means i will set the machine on 1 coin 1play but the credit board will be 4 coins 1 play.

 

[alec_t]

So what you're looking for is a circuit which gets one input signal per coin from the coin-acceptor and outputs one pulse only after receiving four input pulses? That should be doable with a simple divide-by-four counter. We would need to know the voltage and signal type from the coin-acceptor output, and also the input characteristics of the main board (input impedance, or current draw from the acceptor).

 

[colin55]

You just need a 4017 on the output of the coin acceptor.

 

[ChrisP58]

I will assume that the coin acceptor puts out one pulse per coin.

You need a circuit that will put out three pulses only after it sees four pulses. A micro controller would be the best choice. If you need to do it with discrete logic, it will take at least two counters and an pulse generator. So at least two 4017 counters and a 555 timer.

 

[colin55]

This is all rubbish:

You need a circuit that will put out three pulses only after it sees four pulses. A micro controller would be the best choice. If you need to do it with discrete logic, it will take at least two counters and an pulse generator. So at least two 4017 counters and a 555 timer.

I did it with a 4017 35 years ago when "Ghosts and Goblins" was bringing in $150.00 per week from 40cent plays.

 

[asreafkaudeer]

The coin aceptor output signal is just a short to ground and the mainboard emits 5vdc. If i connect a micro switch between the 5vdc and ground it woulld credit the machine. i need diagram and instruction to build a circiut.

 

[asreafkaudeer]

The coin acceptor output signal is just a short to ground, The main board emitts 5vdc. if i put a micro switch between the 5vdc and a ground, I can trigger the machine.

 

[alec_t]

Something like this perhaps?

 

[colin55]

The circuit above will not work.
The output may need to be a pulse and Q4 needs to go to reset.
View attachment 64123

 

[ChrisP58]

Is the output of the coin acceptor a single, clean pulse? If not, it will need to be debounced before it goes into the counter, or it will jump many steps on one coin.

 

[colin55]

The output of all coin acceptors is a clean pulse. Otherwise acceptors would be useless.

 

[asreafkaudeer]

it is a normal micro switch pulse. about 2sec

 

[ChrisP58]

it is a normal micro switch pulse. about 2sec

In my experience, a normal switch is bouncy. Since the output of the coin acceptor goes into a PCB assembly, I expect that there is debounce circuitry on that board.

You have mentioned that you can pulse the board with a manual switch. Does it only see one pulse per switch closure? If so, that almost guarantees that the switch signal is being debounced on the board.

Also, how do you handle exceptions? Such as, if a customer puts in three coins (because that is what he did last week) and it doesn't play. But he doesn't have a 4th coin. Is there a coin return on the acceptor that gives him his money back? If so, you also will need a pulse to reset the counter or the next person to put in one coin will get the game for a big discount.

 

[asreafkaudeer]

There is a big sticker on the machine that say 4 coins 1 play, If the customer did put 3 and do not have the 4th coins i would offer him one coin to complete his game. so far i have not have a working circiut to inrease the amount of coins fior 1 credit. everytime i put the 5vdc coming from the mainboard to ground it gives me a credit.

 

[ChrisP58]

If there are no other issues to be addresses, then colin's circuit from post #9 should do what you need. It does have an RC circuit on the input (pin14) to take care of any switch bounce.

Is there a separate +5V wire from the acceptor? Or is there just one wire that is the output pulse that is normally at 5V?

 

[harold777]

Personally I like 4017's - but yes this cct should be buffered to avoid rogue triggering. Simply an RCnetwork will do it, with a modest time constant.
In practice I suspect the coin-signal will be low-impedance (a microswitch was it?), so the transition from 1-0 will be pretty quick, so the rc network can be quite small.
OP needs to experiment a bit. The 4017 will enable the coin-numbers to be set up to 9, should inflation become serious.

 

[asreafkaudeer]

hi
i would like to have adiagram for that experiment if possible