Slingshot AutofireSingle Coils

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Bob P

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Aug 28, 2023, 6:56:53 AM8/28/23
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Does anyone have a picture they can post showing how the low voltage switch and high voltage connections work? I want to make sure I have this correct and don't fry my board

OPP

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Aug 28, 2023, 7:46:41 AM8/28/23
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I think you use cobrapin, so here is the generic wiring diagram link:  https://pinballmakers.com/wiki/index.php?title=CobraPin
With slingshots, there are normally two switches that are put in parallel.  To parallel a low voltage switch, the processor signal line is soldered to one side of each of the switches.  The other side of both switches is soldered to logic ground.  If either or both switches are closed, the ground is connected which overrides the weak internal pullup resistor in the processor, so the processor reads an active low.
-H

Bob Prince

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Aug 28, 2023, 8:59:43 AM8/28/23
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thanks. i should have noted i’m using cobrapin. i have that article but i would really like to see a picture of this so i have confidence i have it right

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On Aug 28, 2023, at 7:46 AM, OPP <openpinba...@gmail.com> wrote:

I think you use cobrapin, so here is the generic wiring diagram link:  https://pinballmakers.com/wiki/index.php?title=CobraPin
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OPP

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Aug 28, 2023, 8:46:19 PM8/28/23
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OK, here is what I would do if I was worried about wiring, configuration, etc.  Hook up all the wires as expected, but don't turn on your 48V power supply.  Test each of the slingshot switches one at a time making sure that as they close and you hold them closed, test that the driver LED blinks for a brief moment.  (Something like 32 or 48ms).  I believe that the cobrapin board has individually driving LEDs for debugging.  Now is the time to use them to their best ability.

Next test your flipper buttons.  When you press the flipper button, make sure that the driver LED stays on, is pulsed, gets bright then gets less bright depending on if it is a dual wound coil or not.

Do the same with all the inputs that trigger solenoids.  Make sure coils that should be pulsed are pulsed.  (Very important).

I personally feel this should work with or without MPF running and I would verify both configurations.  (One is what is typically termed as white wood mode, and the other mode is using the configuration that is programmed through MPF.  They may be slightly different, but you should know the differences).

Nice, now it is time to turn on the 48V supply.  Plug it in and get ready to unplug it if you hear a solenoid stuck on.  (This is personally the scariest moment for me after I have spent a day rewiring a playfield).  If you don't hear any solenoids stuck on, or machine gunning (can be caused by poorly adjusted switches), start testing the switches again.  Get ready to pull the plug at a moments notice.  Keep it close in hand.

After 5 or 10 minutes, as things seem to be working properly, you can start to slowly gain confidence and not lunge for the power cord at the slightest sound that you aren't expecting.   Bat the ball around with both flippers.  Play gorilla flippers to make sure that pounding on both flipper buttons at once doesn't trip your power supply.  When you have tried everything you can think of, grab somebody else and let them bat the ball around.  A non-pinball person plays pinball significantly differently than a person who "knows" how to play pinball.

That's how I test a rewired/newly wired playfield.  Hopefully that is helpful.
-H

Bob P

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Aug 28, 2023, 9:21:00 PM8/28/23
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Actually its a pop bumper by Gotlieb.
 I've attached a diagram of what I have.
There are  2 coil terminals. I've numbered the terminals C1 & C2
Then there are 2 separate switches each with 2 terminals. I've numbered these terminals S1, S2, S3 & S4
There is already a soldered connection between C2 and S4 that I'm showing in red on the diagram.

I have 4 wires I need to connect:
1. 24V+ (coil power output from J13 plug of Cobrapin board)
2. 24V- (coil output from A plug of Cobrapin board)
3. Switch signal  (from J1 plug of Cobrapin board)
4. Switch Ground (from common ground of J1 plug of Cobrapin board)

To make this really simple all i need is a response that would match the wires with the terminals
ie:
C1 = 1
S2=4 
etc....

Capture.JPG

cobra18t

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Aug 29, 2023, 3:51:17 AM8/29/23
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That switch stack behaves differently than what is standard now. Those were driven by a separate pop board. The pop would fire without processor intervention and the logic switch would activate in response to the pop plunger movement and that is how the processor new the pop had fired. Nowadays, there is just a logic switch that tells the processor it is time to fire the coil.

I would consider running this bumper in a more standard way without the high power switch (S3/S4). This is what I did on my Gottlieb pops:
  1. Wire the coil as a standard coil back to the CobraPin. If it has a diode, make sure that banded side goes to the power lead (24-48V depending on your game) and the non-banded side goes to the CobraPin coil output.
  2. Remove the high power switch (S3/S4) entirely
  3. Move the S1/S2 switch to the top so that S2 is up against the pop spoon
  4. Adjust the switch gap as necessary
In the end, you have a separate coil and switch that each go back to the CobraPin.

cobra18t

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Aug 29, 2023, 3:52:42 AM8/29/23
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... *knew the pop had fired...

bobp...@rogers.com

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Aug 29, 2023, 6:47:40 AM8/29/23
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Ok thanks, I understand that. It’s very simply! The switch just fires the coil. Perfect!

 

I also have an old Gotlieb Slingshot too. I’m guessing I just follow the same idea?

i.e Disconnect what’s there, wire the coil like the pop, keep the actuators wired together and use that as my switch signal

 

Thanks for all the info and that little nugget about the diode banding.

Is any of this documented anywhere? I’ve been watching Jan’s videos and I didn’t see anything about this.

Is the presumption everyone is using new pops that already come configured that way?

OPP

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Aug 29, 2023, 7:09:33 AM8/29/23
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I would be willing to try something even lazier.  Wire C1/C2 as the coil (making sure the diode is in the correct direction).  Then use S3/S4 as the switch input.  You may not need to alter the switch stack and the spoon.

bobp...@rogers.com

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Aug 29, 2023, 7:42:46 AM8/29/23
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Great advice! Thank you!

cobra18t

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Aug 29, 2023, 4:00:18 PM8/29/23
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My only concern with the top switch is that it was a power switch and those don't always make the best connections at low voltage. But OPP is right, it will likely be fine.

Bob Prince

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Aug 29, 2023, 4:08:56 PM8/29/23
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well i would be willing to try another way but again i would need that little crossover chart i provided 

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On Aug 29, 2023, at 4:00 PM, cobra18t <tfule...@gmail.com> wrote:

My only concern with the top switch is that it was a power switch and those don't always make the best connections at low voltage. But OPP is right, it will likely be fine.

cobra18t

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Aug 29, 2023, 4:12:34 PM8/29/23
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Both suggestions use only one switch. OPP's just used the top switch. I removed the top switch and used the remaining logic switch. The choice is yours.

cobra18t

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Aug 29, 2023, 7:00:37 PM8/29/23
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Here is my pop showing 18 gauge coil wires and 22 gauge logic switch wires.
PXL_20230829_225611449.jpg

bobp...@rogers.com

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Aug 30, 2023, 8:24:00 PM8/30/23
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Appreciate everyone’s help, I’ve now got this going.

Is there a place where something like this could be filed for others?

I struggled with this for awhile and this is such a simple fix to let anyone know.

I can’t possibly be the only one using old pop bumpers  

 

 

 

From: mpf-...@googlegroups.com <mpf-...@googlegroups.com> On Behalf Of cobra18t
Sent: August 29, 2023 7:01 PM
To: MPF Users <mpf-...@googlegroups.com>
Subject: Re: [mpf-users] Re: Slingshot AutofireSingle Coils

 

Here is my pop showing 18 gauge coil wires and 22 gauge logic switch wires.

image001.jpg
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