(Topic ID: 159104)

EM Pinball Circuits-Basics to not-so-basic

By SteveFury

7 years ago


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  • 132 posts
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  • Latest reply 2 years ago by RetroDad65
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    Schematic scan 1 (resized).jpg
    Jack Layout.pdf (PDF preview)
    cam timing.pdf (PDF preview)
    Lug_ID.png
    Flipper_Strength_Range.png
    Flipper_Ckt.gif
    Flux_Lines.gif
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    There are 132 posts in this topic. You are on page 3 of 3.
    #101 7 years ago

    Greetings, Happy new year!

    I've been reviewing this thread and realized I didn't include the flipper circuit!

    First it is important to understand why pinball manufacturers designed them the way they did.
    Use of the solenoid seems to be the obvious choice... But the flipper needs to deliver enough power to oppose the pinball and that is the problem with using solenoids.
    Solenoids by nature deliver far less torque when the plunger is extended out of it, versus a plunger retracted within the solenoid.
    Below is an animation explaining the theory:
    Flux_Lines.gifFlux_Lines.gif

    The flipper is a player operated device and needs to be able to withstand being held on for long periods of time. The continuous duty solenoid does not deliver adequate torque in a game. It will be a weak flipper. Below is an example of the result:
    Flipper_Strength_Range.pngFlipper_Strength_Range.png
    Why not just use a very large and powerful solenoid?
    We can beef-up the solenoid to a higher current type but they are designed for intermittent use and will quickly heat up and burn out if left on for only a few seconds.

    A solution is to use a solenoid which contains two coils in one. The first coil being a high current type which is used to deliver enough torque to the flipper. The second coil is of relatively lower power and used exclusively to hold the flipper on until the player releases it.
    The player pushes the flipper button, turning on the high current coil but the high current is only used for a very short time. The EOS switch opens to reduce the current flowing through the coils.

    This End Of Stroke switch is much different than previously discussed. It's different than those used in score reel and bumpers, for example.

    When the flipper is relaxed, the EOS switch bypasses (shorts across) the hold-in coil. When the flipper button is pressed, it forces full current through the heavy pull-in coil. Once the flipper is nearly full-stroke, the EOS switch opens which allows current to flow through both coils. Since the hold-in coil is of lighter gauge wire (and longer) than the pull-in coil, the hold-in coil will do most of the work.
    See the animation below:
    Flipper_Ckt.gifFlipper_Ckt.gif
    Sometimes there is confusion where to connect the EOS switch.
    It will -always- go across both sides of the thinner hold-in coil.

    Great. The flipper coil has 3 connections. How do I know which is which?
    The pull-in coil will almost always be of a thicker, larger gauge wire than the hold-in coil. You can look at the end of the coil itself and usually identify which is which. If there's doubt then a quick check across both coils with a meter will positively identify them. The pull-in will have less resistance. The hold-in will have more.
    The Common connection will have an end of both coils soldered to it; One thick and one thinner coil wire.

    These will be the connections for the graphic below:
    P Pull in coil
    C Common (One end of both coils will be connected to this same lug)
    H Hold in coil
    Lug_ID.pngLug_ID.png

    Basic troubleshooting:
    The EOS switch must open when the flipper solenoid is nearly full-in. That will deliver the most power on the flipper. Warning! it is imperative the switch will positively open upon full stroke. A burned out coil/smoke will result if the switch fails to open.
    It is normal for a flipper to buzz, but it shouldn't sound like a 1960's alarm clock.
    If it is excessively noisy then check for loose mounting parts or a worn-out copper alloy plunger stop, or a bad plunger.

    That's about it for now.
    Enjoy!

    #102 7 years ago

    Happy new year Steve!

    In regards to flipper coils it should be noted on the earliest of flipper games single wound coils were used. Gottlieb used a fairly weak coil that could be held without the use of an end of stroke switch. Williams used a more powerful coil with an end of stroke switch in conjunction with a relay that cut power so the coil would not burn up. It was the combining of these two theories that led to the double wound coil that would become standard later on.

    #103 7 years ago

    Thanks o-din, great info!
    For a related note, my 1947 United Singapore (Flipperless) game had a pair of after-market flippers installed. Those, too were fitted with a weaker, single wound solenoid.

    #104 7 years ago
    Quoted from SteveFury:

    Most pinball coils operate with 24-30 volts. You can go to your auto store and pick out the cheapest package of two brake light bulbs and use them. They must have the same product/part number.

    Welcome back Steve and Happy New Year. (how was your RV trip?)

    I've learned a lot from this thread.

    I have an old Williams machine that has 45 volts instead of 24-30 volts. Would I use say three or four of these lights together for troubleshooting the 45 volt circuit?

    Bruce

    #105 7 years ago

    Hi Bruce
    I live in Europe - we have 220VAC (230VAC) in our buildings. I always wondered "IF and HOW" it works in the USA (having 110VAC in the buildings): Taking a ordinary, simple, old, cheap Edison-Type 110VAC bulb and use it for a Test-Light" --- does it light up (how bright ?) - does a fuse blow (?) - can it be used as a Test-Light ? - does the 110VAC bulb sucks too much current so a mounted pin-relay does NOT operate ? Do YOU want to try the 110VAC bulb ?, greetings Rolf

    #106 7 years ago

    Just discovered this thread now ... One of the best on Pinside. Thanks so much for putting it together - a great read!

    1 month later
    #107 7 years ago

    I want to also thank you for this guide! I have a 1975 Williams Little Chief that I have been working on with help from @rolf_martin_062. I have the schematic and the user manual, and was trying to solve a reset problem. I came across your very informative youtube video

    , which went a long way, as did Rolf's help. I have replaced many broken wires, re-soldered cold solder joints, and the like, and I was still having troubles. Sometimes the playfield was alive, sometimes not. Everything checked out properly with my trusty multimeter. Then I found this, and your brilliant observation that while a circuit may have continuity, it may not be sufficient to allow the current draw of the various relays, etc. BINGO! After building your automotive bulb tester, I found that indeed, there was an issue with the contact on the reset relay that supplied current to the playfield. Multimeter showed all was well. Lesson Learned! I now have a machine that's probably 99% working

    A few observations regarding schematics and the user guide. They are a necessary and excellent resource for understanding and troubleshooting, but they only tell you how the machine SHOULD work, not how it DOES work. With broken wires, mis-wires, etc. I had to do some educated guesswork. Your animations above gave me the idea to create a timing diagram for the score motor cams, since I found instances where one cam driven switch fed into another. I have also been expanding the Jack layouts in the user manual. I was sort of baffled by the names on the layouts, so after much back and forth between schematic and jack layout, using the wire colors listed, I made a tabbed spreadsheet, one tab per jack. Each name was annotated with what it connected to on each side of the connector, along with a from/to designation. Finally, and this is a bit of overkill, I've been working on a document that, for each relay, describes the inputs to that relay, and the outputs. Sort of a mashup of the user manual relay description and the schematic. A lot of work for one game, but these things have increased my understanding of how the game works.

    I've attached one tab (a work in progress) below, along with the cam timing diagram I created.

    Sorry for the length of this, but I hope it is of use to others who may be struggling with their own "beast".

    cam timing.pdfcam timing.pdf

    Jack Layout.pdfJack Layout.pdf

    5 months later
    #108 6 years ago

    Damn. I was doing so good until the schematics started showing up, then it all went downhill.

    When looking at the schematic, my assumption is that power always goes from left to right? I know it's a stupid question, but I can't even find a "starting point" to follow power flow when looking at the schematic.

    #109 6 years ago

    I have the same problem, seems the current "flows everywhere" because it's AC. I also have to memorize silly sentences like Spring Forward/Fall Back and Truth is stranger than fiction so I can remember which is which.

    My brain just doesn't seem wired correctly to follow the schematic diagrams.

    Bruce

    #110 6 years ago

    Which schematic are you looking at? At least for the Bally ones like I have, it doesn't work like that, the power doesn't flow from left to right. There are generally a few voltage circuits set up, which are long wire sets that have a voltage potential between them. All the action (power flow if you want to call it that) happens between those 2 wires. It can get confusing because they often "fold" those voltage circuits back and forth in the schematic. That is done so that the schematic is not really wide and short in dimensions.

    #111 6 years ago

    Are you talking about the 6 volt and 25-50 volt circuits? Those make sense except for the wire in the middle that joins both circuits, that I'm not so sure about. Are the 6 volt and 25 volt currents both flowing back to the transformer on that line?

    Bruce

    #112 6 years ago

    Each of those circuits has a voltage potential across it, 6 VAC for the lights and 25 to 50 VAC for the rest of the stuff. We can call it 6V or 50V understanding that everything is AC voltage (usually).

    There is no positive and negative voltage like you would have in a DC circuit.

    There are then a whole bunch of sub circuits that connect across those circuits. There will always be a resistive load in each one, otherwise you would get a short circuit. For example in the 6V circuit the lamps are a resistive load. Usually there is a switch (or several switches) in each of those subcircuits as well to turn things on or off. In the high voltage circuit the resistive loads are relays, motors, solenoids, etc.

    When you close all the switches in one of those sub circuits then current will flow through it. We don't really have to think much about the current though. It's there, but more importantly we know we have supplied voltage to the resistive load, so it will be activated. It will draw whatever current it needs from the AC supply. In the 6V circuit a lamp or multiple lamps will be lit. An incandescent lamp would draw more current then an LED because that is its basic nature. But we don't need to know that current to understand the circuit. More important is that we know if we supply 6V across the lamp, it will light up.

    In the high voltage circuit, almost all of those sub circuits are normally open most of the time. They just close briefly to activate the resistive load, such as a relay, solenoid, or motor. These all will do their thing when they get voltage across them. A motor will turn, a relay will energize, a solenoid will fire, etc. These things all act very briefly and that's all it takes to make a pinball machine go. Most of these resistive loads in fact would not like being turned on for extended periods, they would burn up from the constant current load (or more accurately the power load which is voltage x current, we always honor Ohms Law). An exception would the lock relay, it is on almost all the time the machine is being played so that needs to be a special relay to handle that constant load or it would fry.

    From there the trick to understanding the EM schematic is to work out how each of those subcircuits gets its job done through the proper closing of its switches at the right time.

    After looking at a pinball circuit in detail, I think there are two main concepts you need to get a good grasp on to be able to understand how an EM works. The first is the score motor and the second is the "lock in circuit". Once you know how those work and interact things start to get a lot clearer. SteveFury has covered these earlier in this thread.

    (Edit) I went back to the beginning of this topic and now I can see how this can get confusing. Probably for the sake of keeping it simple, many of the example diagrams show the power coming from a battery. That battery is a DC source. But that's not the way an EM works. The source is AC. So the current doesn't flow in one direction from + to - like in a DC circuit when the switches close to complete the circuit. The current goes back and forth in both directions very rapidly. But everything still works the same as shown in the examples. Just don't get caught up in the plus and minus aspect of the battery. Again, in the end it is the application of the voltage that is more important than the current flow.

    #113 6 years ago
    Quoted from xsvtoys:

    (Edit) I went back to the beginning of this topic and now I can see how this can get confusing. Probably for the sake of keeping it simple, many of the example diagrams show the power coming from a battery. That battery is a DC source. But that's not the way an EM works. The source is AC. So the current doesn't flow in one direction from + to - like in a DC circuit when the switches close to complete the circuit. The current goes back and forth in both directions very rapidly. But everything still works the same as shown in the examples. Just don't get caught up in the plus and minus aspect of the battery. Again, in the end it is the application of the voltage that is more important than the current flow.

    That's where I got lost. I was able to follow it from the battery in the diagrams, but once it went to the schematics, I got lost because there wasn't a way for me to follow the power flow.

    So does the power come from both sides of the schematic? The OP indicates that both vertical lines on the schematics are bus bars, so does that mean that current can flow from either side?

    #114 6 years ago
    Quoted from Spyderturbo007:

    That's where I got lost. I was able to follow it from the battery in the diagrams, but once it went to the schematics, I got lost because there wasn't a way for me to follow the power flow.
    So does the power come from both sides of the schematic? The OP indicates that both vertical lines on the schematics are bus bars, so does that mean that current can flow from either side?

    )Not to get technical but alternating current does flow back and forth etc.)

    Each manufacturer lays out their diagram a little differently. On Gottlieb diagrams the far right side of the diagram is the 24volt rail, usually a red-white molted lead. Then just to the right of center is the black lead or return for the 24v feed. You'll note most coils are directly attached to the black lead.

    For the left "6v" side the supply is far left with the common return just left of center. If you look at the supply leads of both the 6v and 24v sides you'll see the fuse inline. Commons (returns) are not fused.

    #115 6 years ago

    I understand the 6v and 24-50v circuits and the layouts but the circuits seem to join in the middle and connect to the middle tap on the transformer? How do 6 volt and 24-50 volt currents flow on that same wire?

    In the first scan you can see the 6v circuit on the left and the 45v circuit on the right but what about the middle wire where they join and connect to the transformer's middle tap? It would make sense if the circuits were separated completely but I get lost reading this layout trying to understand which event is supposed to trigger the following event in order.

    Schematic scan 2 (resized).jpgSchematic scan 2 (resized).jpg

    The second scan shows Lock Re which is lock relay, obviously closing it lights the Tilt Lite? Index is obviously the index the score motor stops at but the 45v wire for it (58 = white/black according to the wire color chart) connects to the 6v wire (95 = grey/white).

    I'm trying to understand which triggers which in the second scan. Does it go back and forth like this? Start Re closes triggering the Replay Reset coil then that closes the Lock Re turning on the Tilt Lite? This is where I get lost trying to follow the schematic.

    Schematic scan 1 (resized).jpgSchematic scan 1 (resized).jpg

    Bruce

    #116 6 years ago

    Just think about it flowing from the transformer, down the outer line in the schematic, across the schematic where it can (switches closed etc.) and then returning down the central common wire.

    Consider the schematic to be broken into two separate parts, the low voltage and high voltage side.

    schematic (resized).jpgschematic (resized).jpg

    In your second schematic snippet we see for instance that when the Lock Relay is not energized, the circuit through the TILT LITE is closed so it will light up. When the lock relay is energized that switch changes state and the TILT LITE will no longer be energized through that path.

    On the high voltage side, the REPLAY RESET and other relays will be energized when the START RE is energized (which means that the normally open switch on the schematic is closed) and the switch on the INDEX cam is closed.

    Yes, you then need to work backwards -> what makes the START RE energize? and so on

    #117 6 years ago

    If the Tilt Lite is lit up then that means the Lock Relay switch is closed but where do I look for the coil that energizes the Lock Relay? Should I be looking elsewhere on the schematic for a "Lock Relay" coil or work from left to right on the line to find it?

    Same for the three "Reset" coils that close the Start Relay switch when energized but where do I look to find what's energizing these coils? Do I work backwards up the high voltage line?

    I realize the schematic is logically diagrammed, not a wiring diagram but I get lost looking on the schematic for whatever's supposed to close switches or illuminate the lights.

    Bruce

    #118 6 years ago
    Quoted from PinballFever:

    If the Tilt Lite is lit up then that means the Lock Relay switch is closed but where do I look for the coil that energizes the Lock Relay? Should I be looking elsewhere on the schematic for a "Lock Relay" coil or work from left to right on the line to find it?
    Same for the three "Reset" coils that close the Start Relay switch when energized but where do I look to find what's energizing these coils? Do I work backwards up the high voltage line?
    I realize the schematic is logically diagrammed, not a wiring diagram but I get lost looking on the schematic for whatever's supposed to close switches or illuminate the lights.
    Bruce

    Find the Lock Relay on the high power side of the schematic. See what is required to complete the circuit for it to energize. But note that this switch is a "make/break" switch. When the lock relay is NOT energized the circuit to the tilt lite is completed. When it is energized the switch toggles to the other branch and the tilt lite goes out (at least for that path).

    For the three relays in your schematic, they energize WHEN the start relay is energized. That is when the switch in the circuit shown above closes. So you need to locate the start relay and see how it gets energized.

    #119 6 years ago

    That makes more sense. Will study my schematic and see if I can understand it better following your instructions. I guess it gets easier with practice (hopefully!).

    Bruce

    4 months later
    #120 6 years ago

    Wow, I'm just now finding this thread. SO helpful!

    1 month later
    #121 6 years ago

    Yes, very helpful, thank you!

    1 year later
    #122 4 years ago

    Just stumbled on this thread. What a great wealth of information. The animations are very helpful. Could have used this thread when I first started messing with EM machines. I just love the logic in EM machines. Thanks for all the input on this thread!

    #123 4 years ago

    Excellent job on this post.
    A must read for newbies.

    1 month later
    #124 4 years ago

    Hi pinsiders
    it is more then two years ago that SteveFury - original poster - wrote in here. In pinside I read he went R.V. In his post-1 he invited us "to provide input if we wish".

    A common problem "on the playfield a target (or rollover) is sometimes unlit - sometimes lit. Unlit it is worth (lets say) 100 points --- lit it is worth 300 points. The problem is: Lit (300 points) works - but not the unlit (100 points)." Where to look in the schematics - then in the pin ?

    I show it on Shangri La https://www.ipdb.org/machine.cgi?id=2110 . See the JPG --- whenever some stuff has a light to it: I like to look-up first in the "6VAC-Lights-Section" to learn about steppers / relays involved in the actions. I see a switch on No-3-RED-Relay. I then look-up in the "24-VAC-Section" looking for a relay with "300" in its naming, the 100-Point-Relay and of course "a switch on the No-3-RED-Relay". On the bottom of the JPG I highlited "green" - functioning - activation of the 300-Relay, "red" the path nonworking for to activate the 100-Points-Relay.
    I then locate the No-3-RED-Relay, check the shown switch for cleanliness, proper gaping, closing when the relay activates, wire(s) soldered-on or is there a broken-off wire loose nearby (?) --- AND I follow all the wires soldered-on to the "switchblade in question" - follow the wire(s) in the pin to "other place the wire(s) is soldered-on" - all good ? I have in mind that the schematics is an abstract drawing not showing the real wiring --- in a pin, reality: There is NEVER a "fork-off" of a wire, fork-off from a running wire --- ALWAYS existing solder-lugs are used instead. Greetings Rolf

    0Shangri-La-Work-33.jpg0Shangri-La-Work-33.jpg
    #125 4 years ago

    Hi pinsiders
    another quite common problem: A Score-Drum steps in play - but does not step at "start up / resetting everything". I show it on "Gottlieb Fast Draw" - First-Player-10'000-Score-Drum. See the first JPG, bottom right corner, "my green lines", "Hot, Power" comes up, to the left, through a pulsed switch-4A-on-the-Score-Motor, to the left, up and to the left to many switches named "Z1" and "Z2" --- further to the left to Score-Drums. All "my green wiring" works on start-up / resetting --- but not "my orange wiring". Here again we have "a schematics is drawn abstract - in reality in the pin there is NEVER a fork-off off a running wire - always existing solder-lugs are used - see places I put 'brown 1, brown 2' ". Just theoretically: ONE wire runs from motor-4A-switch to a switch named "Z1" - another ONE wire runs from motor-4A-switch to another switch named "Z1" etc. --- but practically, costs saving, reality in the pin is - see the second JPG - ONE wire comes from the cabinet, Score-Motor-Switch-4A comes up into the backbox to one solder-lug on (example) "switchblade of a switch on the Z2-Relay". Then the wires hops, hops, hops to other switches on Z2-Relay and Z1-Relay. On the other side / blade on all the switches then an individual wire runs to a Score-Drum for to make this Score-Drum reset means step forward towards Zero.

    Most likely "second JPG, my marked orange lines" - in there is the cause of the fault "First-Player-10'000-Score-Drum does not step at start-up / resetting".
    In the first JPG, "my brown 3" - we see: Another switch on the Score-Motor, motor-switch-1A does cause (through other switches on Z1- and Z2-Relay) the stepping (resetting) of Score-Drums.
    To learn about WHICH switch on Z1- / Z2- is responsible for WHICH Score-Drum to reset: I would manually put some points on all Score-Drums - then I'd sneak-in a stripe of paper into ONE such switch (switch can mecanically close but not electrically). Then I'd start a game - big question: WHICH Score-Drum does not reset - I'd then write down "switch-" is responsible for "Drum-".
    This sneaking-in a stripe of paper, start ... write down I'd repeat until I have a list of all switches / all Score-Drums. I'd clean switch "I have marked orange" - use a jumper - connecting "my orange star to one of my green stars" - or connecting "along my marked orange wiring".
    See the JPGs --- of course, not only in the wiring "my orange lines, switch on Z1": The fault also can be "my marked orange !!!" - the "Run-out-Switch on the Player-1-10'000-Score-Drum". Greetings Rolf

    0Fast-Draw-Work-22 (resized).jpg0Fast-Draw-Work-22 (resized).jpg0Fast-Draw-Work-23 (resized).jpg0Fast-Draw-Work-23 (resized).jpg
    1 year later
    #126 3 years ago

    Wow... read it all.. I'm impressed !
    Thanks !

    2 months later
    #127 3 years ago

    When stuff gets serious for me I plot it out on my plotter at 24" x 36". its then easy to read and easy to highlight and mark up to follow a circuit.

    2 months later
    #128 3 years ago

    THANK YOU, I will come back to this - it’s like pinball school 101.....I am a little slow and it will take time yet I like how you build from the very easiest on up.
    LB
    Santa Fe, NM

    1 week later
    17
    #129 3 years ago

    Hi folks!
    I'm glad to see that people are still finding my guides useful.
    God bless and Happy new year 2021!

    #130 3 years ago

    Glad to see you checking in, Steve! And yes, your guide has been a huge help in understanding these machines! Happy New Year to you too!

    3 months later
    #131 2 years ago

    Good info here and useful since my first purchase of On Beam and Space Mission last week. On Beam has an issue I'm tracing down.
    I'm not unfamiliar with schematics, since I repair CNC machines for a living. These old EM machines remind me of the old relay logic CNC's that existed before full on electronic controls were introduced. It can be quite daunting to go through all the combinations of switches and coils, but once familiar with the schematic and machine, it gets much easier.

    2 weeks later
    #132 2 years ago
    Quoted from Wizbangdoodle:

    Good info here and useful since my first purchase of On Beam and Space Mission last week. On Beam has an issue I'm tracing down.
    I'm not unfamiliar with schematics, since I repair CNC machines for a living. These old EM machines remind me of the old relay logic CNC's that existed before full on electronic controls were introduced. It can be quite daunting to go through all the combinations of switches and coils, but once familiar with the schematic and machine, it gets much easier.

    One trick I found is to look at the score motor relays and get the state order down as the motor goes around. It helps in figuring out any timing problems with the score motor relays.

    There are 132 posts in this topic. You are on page 3 of 3.

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