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Thomas the tank engine. TTTE.


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The battle pinny is using logic gates to drive , disable and reverse the flippers into the FET board you have, so far nothing has gone fizz, and as no microprocessor is involved there is no delay from button push to flipper flip ! Also it was fun to create some good old TTL Logic ! Gotta love a truth table
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The battle pinny is using logic gates to drive , disable and reverse the flippers into the FET board you have, so far nothing has gone fizz, and as no microprocessor is involved there is no delay from button push to flipper flip ! Also it was fun to create some good old TTL Logic ! Gotta love a truth table
I guess I'm stuck in the 60s trying to use relays. [emoji16]

It's good to hear it all works well, thanks.

Cheers Trev

 

Sent from my SM-G930F using Tapatalk

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You can't drive a relay directly off a micro controller. You need to up the voltage if above a 5vDC relay coil and also the current. As soon as you do that, while your secondary side of the relay IS isolated, the primary side higher voltage and current is not.

 

That is where an opto coupler comes in. It's primary side can be driven directly off a micro controller and it's secondary side can drive higher voltages and currents.

 

Ah, OK, I'm with you now. Thanks for that!

 

You can even get optos with a darlington pair inside allowing you to drive the opto straight from the micro controller and the darlington pair drive pinball coils directly in perfect safety and use no transistors, mosfets or relays to do any switching.

 

Now, that's a nifty gadget! Do you have any links to such a beast? I've never seen one of those in a pinball machine. Are they expensive? I'm wondering why these aren't all over the place…

 

Michi.

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Ah, OK, I'm with you now. Thanks for that!

 

 

 

Now, that's a nifty gadget! Do you have any links to such a beast? I've never seen one of those in a pinball machine. Are they expensive? I'm wondering why these aren't all over the place…

 

Michi.

 

Opto driving a FET, Good for 60 volts @2amps.

 

At $14.45 your not using to many of them but that is the price you pay for lazy man electronics. Still, they do make them.

 

 

 

A cheaper alternative. 4 in the one unit 80vDC max @1.75amps each. Not opto isolated but isolated none the less.

 

$3.57 a piece.

 

https://au.rs-online.com/web/p/darlington-transistors/0633672/

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@BIG Trev , @kress , @Autosteve , @thegrunta666 @Michi and more.

 

Kudos guys as I'm in total amazement how you can dream up this stuff and think-tank your way through it.

 

A lot of the electronic details I don't understand but I am sincerely in awe of what you guys are capable of achieving:041:

Edited by Railways
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I guess I'm stuck in the 60s trying to use relays. [emoji16]

 

You really want to keep relays and any inductive loads away from your electronics when you can.

 

Relays create more problems you need more electronics to get rid of like spicks, back EMF and contact bounce.

 

To buy a pre-made relay board is actually creating more issues IMO.

 

Each channel from your micro controller that drives a coil could have gone straight to a small transistor and that transistor drives a larger transistor,,(darlington pair), and the larger transistor grounds the coil.

 

One relay controls the active supply to all the coils. During game play the relay closes supplying positive to all the coils, tilt or game over and the relay drops out killing the positive coil supply.

 

When the game is in play, positive power is being supplied to every coil and if a transistor is triggered by your electronics, that transistor connects a ground to the other side of a coil making a full circuit and fires that coil.

 

That is the most cost effective way to control coils with safety that I'm aware of. Not my design. Williams and Bally did it that way and when you look into it, it's easy to see why.

 

Driver transistors are about 5 cent a piece and the power transistors are about 20 cents a piece. There are a couple of resistors required because you can't drive a transistor base off 5 volts and a couple of others for various reasons but they are about 2 cents a piece.

 

MHO, why reinvent the wheel and why use FETS. Fets have been around for nearly as long as transistors and most people don't use them for very good reason. Very susceptible to static and can blow ON , OFF or shorted to there control pin.

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@BIG Trev , @kress , @Autosteve , @thegrunta666 @Michi and more.

 

Kudos guys as I'm total amazement how you can dream up this stuff and think-tank your way through it.

 

A lot of the electronic details I don't understand but I am sincerely in awe of what you guys are capable of achieving:041:

 

I can't fold metal ( not nicely anyway ) I'd like to see some pics of the rail process.

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I can't fold metal ( not nicely anyway ) I'd like to see some pics of the rail process.
Thanks, horses for courses I'd reckon.

 

Some of the time is spent with Mark drawing up what he wants the $$million dollar laser cutter to do on the then flat piece of material so everything is where it should be.

The folding process is the manual side of things using the right size of radii and skill. Remember, the rails we do come out as lasercut, flat blanks. the folding is the key.

 

Mark seems to be getting the hang of it:D

 

Then I pack/wrap etc...

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I can't fold metal ( not nicely anyway ) I'd like to see some pics of the rail process.
How about a write up in the Prototyping section Jeff @Railways?[emoji6] I'd be interested to know what software and file formats are used for the laser cutter and please explain how to work out a bend radius?

Cheers Trev

 

Sent from my SM-G930F using Tapatalk

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I guess I'm stuck in the 60s trying to use relays. [emoji16]

It's good to hear it all works well, thanks.

Cheers Trev

 

Sent from my SM-G930F using Tapatalk

 

I thought you would have used the @Homepin flipper drivers you mentioned would be for sale for homebrew.

https://www.aussiearcade.com/showthread.php/59669-TAG-Thunderbirds-Pinball-Parts-updates-ONLY?p=1139120#post1139120

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Would this be useful?

Gottlieb Aux Driver Board MA1722

[ATTACH=CONFIG]112568[/ATTACH]

https://www.aussiearcade.com/attachment.php?attachmentid=68881&d=1410346919

 

If you bridge the pins on the 74hc273 you could drive the IRL540's directly.

 

ie. If you could get just the PCB from @Homepin and solder in your own irl540 and bridge the 74hc273.

 

That will give you a pre-made driver board - Without having to design & make a PCB run yourself.

 

[Added]

You can get IRL5xx fairly cheap at element 14.

http://au.element14.com/search?st=irl5

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Would this be useful?

Gottlieb Aux Driver Board MA1722

[ATTACH=CONFIG]112568[/ATTACH]

https://www.aussiearcade.com/attachment.php?attachmentid=68881&d=1410346919

 

If you bridge the pins on the 74hc273 you could drive the IRL540's directly.

 

ie. If you could get just the PCB from @Homepin and solder in your own irl540 and bridge the 74hc273.

 

That will give you a pre-made driver board - Without having to design & make a PCB run yourself.

That looks interesting. I'll have to put one on the @Homepin shopping list.[emoji6]

For these small boards it's ridiculously cheap to get them made. It's $5 US for 10 boards plus postage ends up about $2 a board.

I actually enjoy the process of making these boards it's not a chore.[emoji16]

Thanks

 

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That looks interesting. I'll have to put one on the @Homepin shopping list.[emoji6]

For these small boards it's ridiculously cheap to get them made. It's $5 US for 10 boards plus postage ends up about $2 a board.

Thanks

 

Sent from my SM-G930F using Tapatalk

 

If you make your own, Then just get a bunch of IRL540's and 4n25 optocouplers

http://au.element14.com/search?st=4n25

 

Actually the 4n25x should be fine at $0.37 each

http://au.element14.com/search?st=4n25x

 

Generally single 4n25 chips are cheaper than the equivalent multi channel single chip.

 

RS-Components are cheap too.

https://au.rs-online.com/web/c/displays-optoelectronics/optocouplers-photodetectors-photointerrupters/optocouplers/?searchTerm=4n25

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I wouldn't be shy on copper for the power lines either. Those lines, I'm not sure how much current you will be pulling through them but seeing as you have a mile of vacant unused copper it really doesn't hurt having thick tracks.

 

It's only insurance if for some reason excess power does get pulled through them.

 

As a guide look at a 5 amp wire and flatten it with a hammer...That is roughly how fat the track needs to be on your board to handle 5 amps. ( formulas are available)

 

Like I say insurance. If your using a FET or Transistor that is rated at 5 amps and your tracks can only handle 2 amps supplying power to that device, if the device fails you know what is going to smoke don't you.

 

It should be the fuse but you want your next weakest link to be the replaceable part, not the track and you don't want the tracks ever getting hot,

 

They lift and can never carry that much current again once dis-coloured....( a purple colour)

 

Much easier to replace a through hole component than repair a smoked or cooked track.

 

Not trying to tell you what to do Trev. I'd just feel better knowing you over engineered your boards allowing for super thin copper clad used by many these days and copper costs money, No sense in having it eaten away or turned all into a ground plain if you can put it to better use.

 

Last thing you want is smoked tracks when you could have easierly made them 2 3 times wider.

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I wasn't happy with the setup I'd made to lift Harold off the helipad so I cheated. I looked at pics of old EM helicopter games and pinched their ideas. After about 2 days of stuffing around with SketchUp and the 3d printer I've come up with this.

bb1801b622d662728d00d4eafaec24c6.jpged869391f4553ef614e5d6a38ee9636e.jpg I'll put a counterbalance weight (fishing sinker) on the far end.

3b0cc0d19aca060508aeaaac4c269b94.jpg and there will be a push rod to lift it up connected to the black ball joint.

Here are the failures. First off I was going to use a rod bent at 90 deg but(1) the rods I had won't bend unless they're heated so I made an angle bracket on the 3d printer but (2) it looked crap and I really don't think it was a good design.

da53f0b283619602e3bfc030844e54b5.jpg So I went for the post with the rod pivoted on top and ball joint but (3) I made it too small and fragile. So I redrew it and beefed it up but (4) it didn't print properly on the first layer. I tried to print the ball joint bracket next but (5) it didn't print properly so I went back to Cura and put all three pieces on to print at the same time, I added a skirt and supports and tipped the problem bracket over a little and it printed fine. But (6) I now have to print it again in black.[emoji16]a62b4e29aae5daf82207924456b93212.jpg It's not always as easy as it looks.

Cheers Trev

 

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Edited by BIG Trev
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Keep up the good work there fella ! It always the way, what you think is a simple little idea to make, takes 3 days and 10 attempt's to get right. Then someone looks at it and gives it an "Oh, not bad".....let them build one and shed some tears in the process !

Viva la Homebrew !

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No shorted tracks. [emoji16]Fiddly bloody crap smd sh.t.[emoji6]

f16ad928405c47be9663b39432e0dc1c.jpg

4dd6941c14012c2b35b2b318b6735289.jpg

Place a tiny amount of solder on opposite corner pads, place the chip on top and tack it down then tack down the other two corner pins, flood one side with solder, then the other side, use desoldering braid on one side applying downward pressure only removing the excess solder then the other side and if you're lucky nothing has moved and there are no shorts. Wash off the flux residue with a toothbrush and isopropyl alcohol.

You didn't think I soldered the pins individually did you? The chip is just over 7mm long and has 10 legs on each side. They're friggin tiny.

Cheers Trev.

 

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No shorted tracks. [emoji16]Fiddly bloody crap smd sh.t.[emoji6]

f16ad928405c47be9663b39432e0dc1c.jpg

4dd6941c14012c2b35b2b318b6735289.jpg

Place a tiny amount of solder on opposite corner pads, place the chip on top and tack it down then tack down the other two corner pins, flood one side with solder, then the other side, use desoldering braid on one side applying downward pressure only removing the excess solder then the other side and if you're lucky nothing has moved and there are no shorts. Wash off the flux residue with a toothbrush and isopropyl alcohol.

You didn't think I soldered the pins individually did you? The chip is just over 7mm long and has 10 legs on each side. They're friggin tiny.

Cheers Trev.

 

Sent from my SM-G930F using Tapatalk

 

Perfect explanation on exactly how to do this job........one thing though....put a heatsink on the chip temporarily to aid in getting the heat out of the chip as you are soldering it.

 

Massive heat going into that chip when you are soldering the whole side.

 

Last thing you want is it looking pretty only to find all your chips are smoked.

 

A square bar of aluminum placed flat on top of the chip is incredibly handy. No need to attach it, just it's end on the chip face and you can just place the bar till your done.

 

Some guys actually use thermal paste to aid in getting that heat out of the chip doing this process.

 

Just wipe it off after your done or cleaning up your flux.

 

You will be very surprised just how much heat that bar absorbs but better into the bar instead of in your chip.

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