There is such a thing as too strong. DC flippers can and do break plastics etc. It is a relatively trivial change to add a rectifier if you want to go down that road. I had this in a Big Indian I bought a few years back. It came that way, and it was too much. It actually peened to top arch and bent all the metal up. I pulled them out. A well rebuilt flipper is all you generally require. If you decide you need more, an orange or yellow dot will get you there.

I had yellow dots in a Big Indian I owned and they were way too much.

I've never felt the need for DC flippers in any game I've owned. I'm with Todd, too much.

DC flippers in EMs do exist in some of the last Gottlieb EMs produced.

Cleo

That has more to do with the machines being solid state. AC flippers can electronically be very noisy (as in there can send spikes back to the voltage source). They are supplied power from the same power source that the transistor driven solenoids are driven from (for the reason I gave, and it's cheaper to use the DC source than to have separate AC and DC power for solenoids). You don't want that noise running back to the filtered power source.

AC is easier to deal with on coils because of the zero crossing capability.
Switching "off" AC can be as simple as removing a gate voltage on an SCR. Also; if you switch off a relay at it's zero crossing point; you help extend the life of the contacts because the arcing between the points in minimized.

Hit the Deck has DC flippers. 1978. So quiet!

AC is cheaper, no extra parts.

Technically; correct in that the power is DC in that it never goes negative; however,
IS the power rectified AC? sure.
If you look closely; most 80/90s SS machines have a full wave bridge. This still "crosses" zero because of the "off time" of the diodes. I'm fairly sure that the solenoid and lamp matrix Power rails do not have capacitors on them... which allows them to reach the "zero".

On the bally -35 cpus; there is a zero cross detection circuit which is tied to NMI of the cpu; it's at that IRQ where decisions are made to turn off lamps and solenoids.

So, after refuting all the suggestions, the only one left is:
"Just because"

Actually, *that* is incorrect.
The title of your post was "Why *no* DC flippers?" Your question is factually inaccurate, as evidenced by some games, like Hit the Deck and the EM version of Solar Ride.

You were very non-specific in your question, which as it turns out is more accurately stated as: 'Why didn't all the manufacturers, use DC flippers all the time, from the very first implementation of DC pop bumpers?' How can that possibly be answered with 100% accuracy? Then when people offered up ideas, you dismissed them as wrong if they didn't fit the answer 100% of the time.

DC flippers are stronger, that is a fact. They do break more things than AC. That is a fact. Perhaps they felt is wasn't worth it for the EM market to give that up, but changed their mind later. (that is a guess) Again, 3 (or more) companies, perhaps 3 different answers.

DC flippers did, in fact, use more parts than the AC counterparts. You focused on the rectifier, but in the Hit the Deck mentioned above, they used diodes on the DC flippers. Why? I have no idea, and I feel it wouldn't be required, but that is what they did. So your response is actually factually incorrect, there were more parts.

So, perhaps the answer is: "because they didn't all get around to it and had bigger fish to fry".

Except, some do, and I just cited two examples. So, not incorrect. Some do, some don't.

image-42_(resized).jpg

Here's the underside of Neptune, the AAB of Hit the Deck. You can clearly see the diodes on the flipper coils.

As for us "satisfying" you on why manufacturers didn't use DC flippers, first nobody here is required to satisfy you, and second, given that EMs haven't been manufactured for 38 years, there's not a lot of people who are around now who were part of the decision making process at any of them to answer that question. They didn't do it. Just accept it as that's the way it was, and quit picking idiotic fights on here.

The majority of EM games had no DC at all. I hope that helps set your mind at ease.

If you want to know why Williams did not use DC flippers when they had DC pops and slings, Steve Kordek would be the man to ask. However, it's a few years too late for that.

Or why, after using DC when he was at Genco, he went away from it for awhile at Williams until DC returned in the 70s.

You could go on and on with this. Bally used 50v in games for awhile, then they didn't. So did Williams. Why change?

To be honest, you've basically come off as a complete toolbag. You're taken a steaming dump on every idea that anyone has put out. Not really a good way to win friends, influence people, and get good answers.

The answer is, nobody really knows why they did what they did. It's only been pushing 40 years, many of the people in decision making positions back then are long gone and those that are still around are not likely reading this forum.

You ask people a question, then dump on them when they give an honest opinion of why this might have been the way it was. At this point, I doubt anyone really wants to answer your question on this any further.

Here's my best guess then. Williams flippers were always very snappy. In fact some of the snappiest in the business. And flippers can send the ball further up the playfield than either pop bumpers or slingshots. So when they decided to increase playfield action (which is written on a sticker in the game) by adding DC rectifiers, they determined that the flippers did not need it. Or they probably would have gone ahead and done it.

Can the OP please name the bleepin' game he's referring to!!! There were several EMs with DC flippers.
If a manufacturer decided to design a game with DC flippers, they would obviously design the flipper coils to deliver an adequate, but not excessive amount of force to the pinball.
My brother once owned a Gottlieb "Pro Pool" that had yellow dot flipper coils and was converted to DC flippers. Needless to say, the flippers could have driven the ball to the top of a 20' playfield, and as someone mentioned above, the top arch was heavily peened by the relentless hammering of the pinball. He put normal coils in it, and it is now reasonably controlled.

Adding to my post above, the drop targets on the "Pro Pool" were in no danger of being broken though, because it was almost impossible to hit them with the flippers! Because they were so powerful, the flippers simply drove the ball straight up to the arch most of the time. If those "mods" weren't bastardizing the game, I don't know what!

It's probably a Williams from the mid 70s as they were the ones that went with DC pops and slings but not flippers. I forget what the first one was but I think they stuck with it until the end. As opposed to Gottlieb that fully rectified their playfield in some of their last few games.

Bally just threw 50 volts in there in the 70s and said here ya go!

Of course, that isn't what you originally said, right?

Here, let me remind you:

The semantics thing can go both ways. See how that works?

Black Jack EM is a very rare game. I saw one recently at auction. I didn't know Bally was using DC coils in their EMs at that time.

Seriously, what the actual F***?!?

You've been snippy towards all answers. but this last one takes the cake:

Instead of just saying "I meant games with DC pop-bumpers" you turned it into a lecture.

Several people have given you valid answers, but instead of clarifying what you meant, or just saying out right you don't understand, you come back with:

You seem to want to argue ANY answer you get. I can just see the mods stepping in to shut this down.

Bally had 50v games in the 60s too o-din. I own one of them. It plays fast.

Quoting you because it is easier than going back and quoting o-din - I might know this one!

Bally used 50V to make things easier on the manufacturing and maintenance side (for operators) since their bingos were primarily 50V. Bingos were the big money-makers, so why retool everything to use 24V just for those silly flipper games?

Many of the bingo assemblies were ported back to the flipper games made after 1963 (when Bally started making flipper games again), and they started thinking about modular playfield assemblies and the like. Operators wouldn't need a second set of fuses or a special flipper tech vs. their normal (usually highly skilled) bingo techs.

Not germane to the conversation about why not DC flippers, but there you go.

Pinside why so negative?
Did anyone actually read what the ops initial questions were?

Basically this post,

Turned to this post in under 25 responses.

Well done. I didn't think it possible in a EM Thread.

I actually clicked on this post to see if someone actually knew why. And maybe I could learn something new.

But now drained.
But before I drained it I took this pic of the results of me reading it.

Screenshot_20160623-104732_(resized).png

Yep. Capersville is 50 volts. All my 50s Williams games are 50 volts too (actually 54), and have some of the snappiest action of them all.

One more thing to consider is how flipper coils are different than other coils in the game.
1. They are higher power and thus lower resistance than other coils.
2. They are triggered by the user vs. the ball.
Normally you have coils firing one-at-a-time as the ball hits pop bumpers and sling shots. Flippers can fire at any time, which means you can have two flipper coils and a playfield coil energized simultaneously.

This leads to a design point that has to handle significantly more current once you add the flippers to the DC power. High-current diodes and bridges are common today, but I suspect they were quite expensive back in the 1970s. (Anyone still have an old electronic catalog to check?)

I may be wrong, but I believe the Bally is running twice the voltage of the other two. That all figures in when they are fusing games.

Two thought come to mind.

They where Tesla fans!

And

Well I'm glad you're not ignoring me!

You're the only one left JR.

Well; JR is being ignored in this thread because he drained it. :S
Maybe he should make a more significant donation to Pinside as his ignore list appears to be a mile long... that much data costs pinside more than the average user in network and cpu bandwidth.

Not sure what *I* did to be ignored; but his loss IMHO.

Drained it? Did no such thing. Anyone wants to ignore me, so be it. No skin off my nuggets! Mr. Zitt, I wonder how you're privy to such information.

I was refering to Erak... not you ... in his "ignored" post; he stated he drained it after that post.

OK, no problem.