(Topic ID: 226970)

Ever convert a mechanical switch to an opto?

By BobLangelius

5 years ago


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#1 5 years ago

Every once in a while a slow shot up the left ramp on my Funhouse will get stopped and stuck on the switch on the ramp behind rudy's head, under the little house thing....

Was thinking of converting this to an opto.

Anyone know of a stock board (IE. Williams board)i could use to do this?

Bob

#2 5 years ago

I'd suspect your switch. Mine even if I just set the ball right under it it can still actuate fine.

But, for the fun of theorizing: it looks from the manual like the existing opto board has three slots, only two of which (hot dog ramp and rudy's mouth) are used? So I guess you could just plug into J4 there. The other concern would be whether they're inverted or not...

#3 5 years ago

Optos will need a 12 volt supply, and they’re read by the MPU backwards. A standard microswitch is normally open, and when it closes to complete the circuit, it’s registered as a hit.

Optos are read as being normally closed, and when the beam is broken, it opens the circuit and the MPU registers it as a hit.

So while you could very likely piggy back a 12 volt supply, you’d still have to change the programming/code to tell the software what would constitute a hit, otherwise the game will just see the converted ramp switch as always being permanently closed.

#4 5 years ago
Quoted from zacaj:

I'd suspect your switch. Mine even if I just set the ball right under it it can still actuate fine.
But, for the fun of theorizing: it looks from the manual like the existing opto board has three slots, only two of which (hot dog ramp and rudy's mouth) are used? So I guess you could just plug into J4 there. The other concern would be whether they're inverted or not...

It's not that it doesn't actuate, it does, But the slight friction of the arm, on a rare occasion, stops the ball on the ramp. Am i understanding your reply correctly??

#5 5 years ago
Quoted from mbaumle:

Optos will need a 12 volt supply, and they’re read by the MPU backwards. A standard microswitch is normally open, and when it closes to complete the circuit, it’s registered as a hit.
Optos are read as being normally closed, and when the beam is broken, it opens the circuit and the MPU registers it as a hit.
So while you could very likely piggy back a 12 volt supply, you’d still have to change the programming/code to tell the software what would constitute a hit, otherwise the game will just see the converted ramp switch as always being permanently closed.

Couldn't i invert that somehow?

#6 5 years ago

Seems like it would be easier to adjust/replace the existing switch so that the ball doesn't lose as much momentum passing through.

#7 5 years ago
Quoted from BobLangelius:

It's not that it doesn't actuate, it does, But the slight friction of the arm, on a rare occasion, stops the ball on the ramp. Am i understanding your reply correctly??

I mean, even a ball with zero momentum, rested against my switch blade, will still roll through and down the ramp. The switch shouldn't be able to stop it

Quoted from BobLangelius:

Couldn't i invert that somehow?

Not with an existing board, you'd need a custom one.

#8 5 years ago
Quoted from mbaumle:

So while you could very likely piggy back a 12 volt supply, you’d still have to change the programming/code to tell the software what would constitute a hit, otherwise the game will just see the converted ramp switch as always being permanently closed.

Adding a logic inverter chip might work.

#9 5 years ago

Better just replace and will be good for years
Optos can go flaky to btw

#10 5 years ago
Quoted from BobLangelius:

It's not that it doesn't actuate, it does, But the slight friction of the arm, on a rare occasion, stops the ball on the ramp. Am i understanding your reply correctly??

This is a problem with some of the switches.

Original cherry switches have a much lower force required than the newer Chinese ones.

Get a few from Bryan Kelly while he is making them up with diodes it's a great deal.

He has a continuous thread, just PM him.

#11 5 years ago

Thanks all. I'll get some switches from Bryan

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