Author Topic: Tank II (Read 72619 times)

blinddog · « **Reply #240 on:** March 01, 2008, 08:06:34 pm »

Well now I’m not sure. Have you ever come across something that proves you were wrong and probable have been for quite some time even though you were sure you were right. I've started second guess myself on the ~ or at least the ~ on top of the equals looking at the schematic it could very well mean AC voltage. You might not want to believe that ~ thing I just said till it’s proved right.

ChadTower · « **Reply #241 on:** March 01, 2008, 08:12:08 pm »

Context tells me it is AC here. In a mathematic context, that is "almost equals", but here I can't see it being anything other than a differentiator between AC and DC.

whammoed · « **Reply #242 on:** March 01, 2008, 10:21:08 pm »

Quote from: ChadTower on March 01, 2008, 08:12:08 pm

Context tells me it is AC here.

You are correct:
http://www.kpsec.freeuk.com/symbol.htm

Level42 · « **Reply #243 on:** March 02, 2008, 04:45:05 am »

Yes, it's a graphical representation of an AC (sinus) voltage. Just like it looks on a scope.

blinddog · « **Reply #244 on:** March 02, 2008, 11:52:41 am »

I agree that the sine wave ~ by itself is a symbol for AC voltage but the document I was referencing (VGL power schematic posted here on page 6) has a ~ on top of the = and originally I stated it means "the approximate value" actually I said it meant about but approximate value is a better phrase. I then started wondering if I was mistaken but looking at the schematic again I noticed that tp 2 and tp 3 are coming out of a full bridge rectifier which would make them DC voltages and now I’m thinking my originally statement is correct

ChadTower · « **Reply #245 on:** March 02, 2008, 05:22:09 pm »

Then how is one to know which points would be AC and which would be DC? Just by knowing the circuit?

whammoed · « **Reply #246 on:** March 02, 2008, 07:11:21 pm »

Didn't know there was an = below the ~. Are any of the voltages AC? They are all designated as either + or -. AC is neither + nor - ? Yes?

Fozzy The Bear · « **Reply #247 on:** March 02, 2008, 07:34:16 pm »

Quote from: whammoed on March 02, 2008, 07:11:21 pm

Didn't know there was an = below the ~. Are any of the voltages AC? They are all designated as either + or -. AC is neither + nor - ? Yes?

Electronics 101 now in progress... No Talking In Class!! And spit out that chewing gum, boy!!

It IS AC Volts..... Points 1, 2 and 3 (also shown on the circuit diagram inside circles) are a part of the "Bridge Rectifier" that is converting those AC Volts to DC. The Bridge Rectifier is the circuit made up of the 4 Diodes set out in a diamond pattern at the lower left of the diagram.

In answer to your question about AC being + or - ..... yes it can be. The bridge rectifier works on a principle called half wave rectification, to smooth out the constant + to - swinging of the Alternating Current. It works by chopping out half of the sine wave that you can see on the oscilloscope. Hence it's still Partly AC at those points on the diagram, but only contains either the negative or positive half of the wave. So while it is still Alternating Current, at those points in the circuit. It is only swinging between +V and 0V OR -V and 0V so on a meter it will look to be either positive or negative.

The symbol is shown as a wave over an equals sign to show that at that point in the circuit it is half wave rectified. The symbol acually represents AC Over DC or AC/DC.

The bits that only contain negative are sent out of the rectifier one way and the bits that only contain positive are sent out of the rectifier the other way.... this is done by the diodes which only allow current to travel in one direction. So now that we have half wave rectified current (effectively either positive lumps or negative lumps), we can pass that through smoothing capacitors and voltage regulators to convert it to a true stable DC +- Current.

Hope that expalins how it can be alternating current but Positive Alternating OR Negative Alternating.

Best Regards,
Julian (Fozzy The Bear)

whammoed · « **Reply #248 on:** March 02, 2008, 08:40:43 pm »

But point 1 is straight from the transformer. Shouldn't it be strictly AC at that location, and if so what is the ~ over = for there?

Quote

So while it is still Alternating Current, at those points in the circuit. It is only swinging between +V and 0V OR -V and 0V so on a meter it will look to be either positive or negative.

I'd buy that if there were only one diode in the diagram but there are 4. Like you said a "Bridge Rectifier".
Points 2 and 3 are fully rectified, not half wave rectified. It's not filtered but current is only flowing one way.

http://en.wikipedia.org/wiki/Rectifier

Fozzy The Bear · « **Reply #249 on:** March 02, 2008, 08:53:55 pm »

Quote from: whammoed on March 02, 2008, 08:40:43 pm

But point 1 is straight from the transformer. Shouldn't it be strictly AC at that location, and if so what is the ~ over = for there?

You are quite correct about that.....

Quote from: whammoed on March 02, 2008, 08:40:43 pm

I'd buy that if there were only one diode in the diagram but there are 4. Like you said a "Bridge Rectifier".
Points 2 and 3 are fully rectified, not half wave rectified. It's not filtered but current is only flowing one way.

You are quite correct again..... However it is still lumpy DC... That is, that at point 2 it is swinging between 0V and -V and at point 3 it is swinging between 0V and +V so it's not true DC, which has those lumps smoothed out to make it constant +V or constant -V. Hence the symbol. At those points it is still alternating positive or alternating negative. Hence the AC/DC symbol.

Best Regards,
Julian (Fozzy The Bear)

Level42 · « **Reply #250 on:** March 03, 2008, 02:20:59 pm »

I was always told that an AC current is only AC when it actually crosses the 0V line. SO, current flows one direction at one moment, then the other way the next moment.

So, although you could call it a "pulsed" DC, it's still already DC between points 2 and 3.

Anyway, a good explanation Fozz !

Also, don't forget about the rectification by CR20 and CR21. Everything behind those (so, across C42) is also DC.

whammoed · « **Reply #251 on:** March 07, 2008, 01:30:34 pm »

So what's the word? Been too busy to work on it?
I haven't been able to cap my G07 since I've been at the hospital all week...going home today.
BTW, you took all the moon pies. Got my order from Bob yesterday and not a single pie.

I find the restoration/repair threads most interesting these days, so post something if you got it eh?

ChadTower · « **Reply #252 on:** March 07, 2008, 01:32:36 pm »

Why were you at the hospital? Everything okay?

Haven't really touched the game since my last post. I was getting too burnt out on it. I did finish Paper Mario Thousand Year Door, though.

whammoed · « **Reply #253 on:** March 07, 2008, 01:45:18 pm »

Quote from: ChadTower on March 07, 2008, 01:32:36 pm

Why were you at the hospital? Everything okay?

Haven't really touched the game since my last post. I was getting too burnt out on it. I did finish Paper Mario Thousand Year Door, though.

My wife had a hysterectomy. She had a hematoma from it which is why we didn't go home yesterday, but everything seems to be ok now, so we are going home today. Thanks for asking.
I can understand getting burnt out on that, it's quite the undertaking.

ChadTower · « **Reply #254 on:** March 07, 2008, 01:53:39 pm »

Glad to hear she's okay.

shardian · « **Reply #255 on:** March 07, 2008, 02:16:53 pm »

Once you are done, you think you could write up a restoration article for Gameroom magazine?
I love the articles written by the E.M. restoring guy known as "The Doctor". The issues you have gotten into with the B&W monitor would be a neat read to most, I would think.

As a bonus, you would get paid!

ChadTower · « **Reply #256 on:** March 07, 2008, 02:20:19 pm »

I've PMed back and forth with Kevin on that before... it's not likely going to happen. Not with this project, anyway. I'm not even a Gameroom subscriber.

I don't think I am comfortable writing technical articles in an area where I am such a clear amateur. It doesn't feel right.

Now, when I do the Black Knight restoration that is coming up... maybe. That one would be looooong, though.

ChadTower · « **Reply #257 on:** March 11, 2008, 09:06:35 am »

I was poking around this some more with the DMM the other day. I finally came to the decision that I had two solid goals on this project: make this game nice and reliable again and learn quite a bit in the process. I have already learned a ton through a whole lot of reading and a bunch of help from you guys (thank you for that) and a couple elsewhere. Looking at the queue of projects I have that I want to work on more than this one, and how long this one was taking me, I decided to bring this game to a pro. It is now in the hands of this guy. His website isn't that great but he is easily the best tech I know. I bet he gets it running well inside of two hours unless he runs into a dead part he doesn't have on hand.

When it comes back I'm going to get some quality pics of whatever parts anyone would like to see, get it back together, and probably put it up in my son's room. I'll probably scan the monitor bezel for the art library as well.

Next project is also going in to the same guy - I have an Asteroids Deluxe, complete, that isn't far from working. I'm bringing the monitor and boards in for repair and will be cleaning up the cab myself. That should be a good short one.

shardian · « **Reply #258 on:** March 11, 2008, 09:35:59 am »

Don't forget to use the $5 off coupon!

ChadTower · « **Reply #259 on:** March 11, 2008, 09:39:19 am »

Heh. I do enough work with him it won't matter. We give each other stuff for free at times, occasionally I'll help him out by sourcing a hard part or finding a buyer for a particularly hot machine. I send a lot of local folks his way, too, as he doesn't do much to get his name out there and as you know we come across a lot of people in our collecting travels.

If you're ever in this area, it's worth a peek in his shop... he has a few thousand square feet and it was so crowded with cabs this week I had to climb over games to get in.

EDIT: Found my original AD project thread. Man, what a newb that guy was.

whammoed · « **Reply #260 on:** March 11, 2008, 09:52:37 am »

Cool. Can't wait to hear what he does to get it running.

rodo · « **Reply #261 on:** March 11, 2008, 10:27:21 pm »

yes, and I'm curious to see how much his fees are too.

whammoed · « **Reply #262 on:** March 19, 2008, 10:08:10 am »

Any word yet?

ChadTower · « **Reply #263 on:** March 19, 2008, 10:10:40 am »

He still has it. Last I talked to him he had poked around and agreed that the problem was likely in the power supply section of the PCB. He hadn't done anything to it yet, though. Right now is a very busy time for travelling techs - all of the summer joints are getting their stuff cleaned up and repaired for the upcoming season. Side jobs like this get back burnered in favor of larger clients.

danny_galaga · « **Reply #264 on:** March 21, 2008, 06:33:06 am »

Quote from: ChadTower on February 29, 2008, 12:57:44 pm

Awesome! The project even brought in a new member. Welcome.

now wheres that pitchfork...

ChadTower · « **Reply #265 on:** March 24, 2008, 09:02:23 am »

The pitchforks are kept in PnR. That's where all the ---That which is odiferous and causeth plants to grow--- is.

rodo · « **Reply #266 on:** March 31, 2008, 06:05:34 am »

Right...I've had enough with the pitch fork jokes...ARRRRGGGHHHHH!

Ok, that feels better.

As I mentioned before, I don't have the luxury of space. I live in a small Tokyo apartment, so instead of collecting cabs, I collect 'untested' boards, repairing them where possible, building JAMMA adaptors for them and playing them on my supergun. It's not perfect, but it's better than nothing, and it keeps me entertained.
So there is no classic cab to JAMMA conversion/hacks involved, so you can all put away the pitch forks ;-)
In fact I truly try to keep any repairs I do as original as possible..I'm old school like that.

At present I'm trying to fix an old Midway Guided Missile, Midway SI (I actually have another that I repaired some time ago, but this one is giving me trouble), and a Gyruss (with some character issues). if you are interested I have just started keeping a log of my fixes/issues here:

http://web.mac.com/lord_philip/Arcade/Midway_Space_Invaders.html

Anyway...enough with the off topic conversation.
So, I'm about get ready for building an adaptor for my tank PCB and have ordered the parts from Jammaboards.com, and I hope to have them arrive sometime next week. I will look locally for a power supply, as the ebay sellers are just asking far too much for shipping to Japan.

So my question is, can anyone confirm that the voltages that Chadtowers is getting from his PSU (14.8 and 7.3) are in fact correct? It's easy for me to find an AC PSU here that does 12.6ac and 6.3ac, but anything higher seems a little difficult here in Japan (don't know why). Just wanted to be sure before I slap down some hard cash.

...now where did I put that pile of smurf-poop.

P

rodo · « **Reply #267 on:** April 03, 2008, 10:45:31 am »

Quote from: Level42 on February 26, 2008, 03:39:43 pm

He should GIVE you the PCB's to make at least one piece of arcade gaming history completely working....

Sorry, I feel compelled to reply to this... Level42, I have a dead Atari Centipede (constantly resets), I see you have one also, please private email me and I'll reply with my shipping address so that you can send me yours for free.

Anyway...so I spent the last few hours replacing some obvious broken parts on my board, and hooked it up to my newly purchased PSU. What would you know...it works!

Seems to have a few issues with white tank not firing (and maybe others, but I'm not 100% sure yet), and I guess there isn't really an attract screen, which kind of threw me off at first.

Next step, solder up a proper adaptor so I can get rid of this crazy mess of wires.

P

Level42 · « **Reply #268 on:** April 04, 2008, 07:22:01 am »

Quote from: rodo on April 03, 2008, 10:45:31 am

Quote from: Level42 on February 26, 2008, 03:39:43 pm
He should GIVE you the PCB's to make at least one piece of arcade gaming history completely working....

Sorry, I feel compelled to reply to this... Level42, I have a dead Atari Centipede (constantly resets), I see you have one also, please private email me and I'll reply with my shipping address so that you can send me yours for free.

Uhhmmmm. No.

Don't take everything I say so literary.

Besides, you can get Centipede PCB's by the dozens everywhere.

rodo · « **Reply #269 on:** April 04, 2008, 10:48:12 am »

Quote from: Level42 on April 04, 2008, 07:22:01 am

Don't take everything I say so literary.

i'll remember that in the future.

ChadTower · « **Reply #270 on:** April 04, 2008, 11:00:22 am »

Quote from: rodo on April 04, 2008, 10:48:12 am

Quote from: Level42 on April 04, 2008, 07:22:01 am

Don't take everything I say so literary.

i'll remember that in the future.

He means literally. He was joking with the original statement - we have a pretty dry sense of humor around here.

rodo · « **Reply #271 on:** April 04, 2008, 11:22:18 am »

Still no word on the board?

I'm having some problems figuring out how to adapt the tank controls to a 4 way joystick...see here:

http://groups.google.com/group/rec.games.video.arcade.collecting/browse_thread/thread/7cbcad2e42a0335f/7cac0a322691f09e#7cac0a322691f09e

So I gave up for tonight. Off to sleeeeeeeeeep.

rodo · « **Reply #272 on:** April 05, 2008, 10:11:14 am »

Much progress made:

http://web.mac.com/lord_philip/Arcade/1974_Kee_Tank.html#0

Level42 · « **Reply #273 on:** May 19, 2008, 07:12:21 am »

Whatever happened to this project ?

In fact: Whatever happened to Chad ? Normaly he replies to about any thread here....hope he's OK ?

In the meantime chad, you could consider getting this over from Germany. It's a steal :S

Shorten Those Links!

SirPeale · « **Reply #274 on:** May 19, 2008, 11:56:17 am »

Chad's okay. He's just taking a break from BYOAC for a while.

Level42 · « **Reply #275 on:** May 20, 2008, 01:09:46 pm »

Sorry about the link.

I guess Chad is in BYOAC-forum rehab ?

Seriously, glad he's OK.

ChadTower · « **Reply #276 on:** August 05, 2008, 01:47:23 pm »

It's time to recover this sucker from the guy who took it in for repair... haven't heard anything from him since I dropped it off.

hatrick · « **Reply #277 on:** August 06, 2008, 10:43:45 am »

I just read through this thread as I am troublshooting an Atari/Kee Sprint 2 game (1976).
It also uses a b&w monitor (23") and has the power supply on the PCB.
So far I've had to replace the LM323 which is the +5volt regulator, and the 2ohm resistor in the same circuit. I'm still getting slightly higher DC voltage than I'd like to be sending to the 74 series IC's, so I'm going to try replacing the caps next. The Sprint 2 board also uses those 8000uf caps and they are darn near impossible to find. I've decided to go with the 8200uf caps, but I'm going to have to go with radial rather than axial on those.

Sorry to throw this into your thread, I'm interested to see how yours turns out. I love working on these old boards, but finding parts can be a beeotch.

ChadTower · « **Reply #278 on:** August 06, 2008, 10:48:22 am »

Welcome! Nice on the Sprint 2. I think I ended up going with 8200uf too and I definitely had to go radial. It was sort of ugly with a jumper for one lead, and some hot glue to keep it all secure, but it did work as far as I could tell.

hatrick · « **Reply #279 on:** August 06, 2008, 03:43:04 pm »

FYI...I saw a post on KLOV for sale section where a guy was selling a complete working Tank II game for $40.
It was a recent for sale post in the last day or so.


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