Coin Pulse Circuit ?

rtw · Post by **rtw** » Mon Sep 10, 2007 6:43 pm

Does anyone have the schematics for a circuit which can generate
a coin pulse ? I have a coin button on my cab and if I hold it down
to long I get a coin error on some games. ideally what I want is a
short pulse to be generated regardless of how long I hold down the
button.

rtw

dpful · Post by **dpful** » Mon Sep 10, 2007 7:38 pm

not the answer you were looking for, but I have my cab wired to use the test switch instead of the coin switch and it works perfectly on ALMOST all my games (I think ghouls 'n' ghosts is the only one of mine that doesn't get credits through the test switch).

rtw · Post by **rtw** » Mon Sep 10, 2007 7:55 pm

dpful wrote:not the answer you were looking for, but I have my cab wired to use the test switch instead of the coin switch and it works perfectly on ALMOST all my games (I think ghouls 'n' ghosts is the only one of mine that doesn't get credits through the test switch).

I think you mean service switch

And there are too many of my games
which do not use the service switch. Bubble Bobble to name one...

rtw

neorichieb1971 · Post by **neorichieb1971** » Mon Sep 10, 2007 9:20 pm

Surely this is just some sort of delay mechanism before the next pulse is triggered. Ever thought of making your supergun big enough for coin box and putting a real coin mech in there?

rtw · Post by **rtw** » Mon Sep 10, 2007 9:45 pm

neorichieb1971 wrote:Surely this is just some sort of delay mechanism before the next pulse is triggered. Ever thought of making your supergun big enough for coin box and putting a real coin mech in there?

No this is not just a delay mechanism, it's a one shot of sorts.

Supergun ? I play erect

rtw

segasonicfan · Post by **segasonicfan** » Mon Sep 10, 2007 11:09 pm

yeah, what you need is a simple 555 timer circuit. Basically you want to build an autofire coin button. Check out this thread for lots of info on that:

http://shmups.system11.org/viewtopic.php?t=16211

you might have to lower the pulse a bit for coin input but that would only require changing a resistor or two.

-Segasonicfan

viletim · Post by **viletim** » Tue Sep 11, 2007 9:47 am

[quote]yeah, what you need is a simple 555 timer circuit. Basically you want to build an autofire coin button.[/quote]

Not quite, you can keep the 555 but wire it in a 'monostable' configuration. The autofire circuit is an 'astable' so it will retrigger itself (I don't think that's what the OP wanted).

rtw · Post by **rtw** » Tue Sep 11, 2007 10:48 pm

viletim wrote:
yeah, what you need is a simple 555 timer circuit. Basically you want to build an autofire coin button.
Not quite, you can keep the 555 but wire it in a 'monostable' configuration. The autofire circuit is an 'astable' so it will retrigger itself (I don't think that's what the OP wanted).

viletim, could you draw a circuit describing what you mean please ?

rtw

viletim · Post by **viletim** » Wed Sep 12, 2007 11:49 am

rtw,

See http://www.zen22142.zen.co.uk/Circuits/ ... 55mono.htm for an explanation.

I've drawn up a more practical circuit. This includes switch debouncing (via C2) and an open collector output. The length of the pulse on the output is ~24mS, sound about right?

rtw · Post by **rtw** » Wed Sep 12, 2007 5:02 pm

viletim wrote:rtw,

See http://www.zen22142.zen.co.uk/Circuits/ ... 55mono.htm for an explanation.

I've drawn up a more practical circuit. This includes switch debouncing (via C2) and an open collector output. The length of the pulse on the output is ~24mS, sound about right

Thank you very much

Now to round up a few components and actually
build it. I think 24ms is right. I have the formula so I can adjust it if necessary.

rtw