Atari Video Music - Needs power supply

[acvieluf]

Hey all, i am waiting on some design work and parts for my mame cab, and thought i'd get some advice from you all. 

I have had an Atari Video Music unit for a long time now, and it's always had it's "wall wart" power adapter chopped off.  The original runs 16.6v 100mA AC power.  I have found a wall wart adapter that runs that in DC power, but that's it.

I know i can run different voltages and mA, but i don't know which one can be more, and which one can be less.

Here's a YT clip, if you've never seen an Atari Video Music: 

These are notoriously susceptible to static and electrical damage.  For all i know, it's a dead box.  But i'd still like to try.


Any suggestions? (preferably cheap, as i don't want to throw money away on something that can't work)

[chopperthedog]

Old Peavey rack gear ran on 16v ac. bet they're cheap on amazon.



good day.

[yotsuya]

I know their website leaves a LOT to be desired, but I'd contact these guys if I were you:

http://best-electronics-ca.com/

[ChadTower]

The original runs 16.6v 100mA AC power.

100mA?  Can that be correct?

[Howard_Casto]

Huh.... I suppose it could be... Atari did some weird stuff with power back in the day. 

I was thinking that Ben Heck did an Atari video project a while back... maybe there is some info on his site?

Btw.... we totally want videos when it's working. 

[acvieluf]

The original runs 16.6v 100mA AC power.

100mA?  Can that be correct?

Yep. Here's a close-up of an adapter.


Sent from my Atari 2600

[acvieluf]

Huh.... I suppose it could be... Atari did some weird stuff with power back in the day. 

I was thinking that Ben Heck did an Atari video project a while back... maybe there is some info on his site?

Btw.... we totally want videos when it's working. 

Yeah, that was from January, which is awesome, cause I had never seen it before until I was looking things up for this post! It's awesome, but...he doesn't have to deal with the problem of not even HAVING an adapter. So thats step one, for me.

Sent from my Atari 2600

[Howard_Casto]

Ok, perhaps a roundabout solution.  I got a email about a DIY benchtop power supply project:

http://www.instructables.com/id/Adjustable-High-Current-Lab-SMPS-Out-of-a-Standard/

Maybe you can gleem enough knowledge out of it to rig up a 16.6v 100mA  power supply.

[pbj]

I've got a couple of weird AC/AC power supplies laying around.  I'll check my pile this evening.

[acvieluf]

I've got a couple of weird AC/AC power supplies laying around.  I'll check my pile this evening.

Man, that would be AWESOME.

Sent from my Atari 2600

[acvieluf]

Ok, perhaps a roundabout solution.  I got a email about a DIY benchtop power supply project:

http://www.instructables.com/id/Adjustable-High-Current-Lab-SMPS-Out-of-a-Standard/

Maybe you can gleem enough knowledge out of it to rig up a 16.6v 100mA  power supply.

Thanks, I'll check that out when I get home!

Sent from my Atari 2600

[ChadTower]

AC to AC Wall Adapter Transformer 16 Volt @ 1000mA Black Straight 2.1mm Female Plug

[acvieluf]

AC to AC Wall Adapter Transformer 16 Volt @ 1000mA Black Straight 2.1mm Female Plug

Sorry for the dumb question, but is it the mA that I can "overshoot?" I did this once for an old NES, but couldn't remember if it was the voltage or the milliamps.

Sent from my Atari 2600

[ChadTower]

AC to AC Wall Adapter Transformer 16 Volt @ 1000mA Black Straight 2.1mm Female Plug

Sorry for the dumb question, but is it the mA that I can "overshoot?" I did this once for an old NES, but couldn't remember if it was the voltage or the milliamps.

Sent from my Atari 2600

You want the voltage to be in the proper range and the amperage to be equal or greater than.  The device will pull as much juice as it needs.  Proper voltage will ensure that it cannot try to pull too much at once and thus fry something.

[pbj]

Take a look at the schematic:


http://www.atarimuseum.com/videogames/dedicated/videomusic/vm-sidea.jpg

You can bypass the AC adapter entirely and feed DC voltage to the test points on the board.  Looks like you need -9V (TP3), -5V (TP1), and +8V (TP2).  Playing with a 12V supply, some resistors, and an inverter circuit should coax all those out.

[ChadTower]

That's a thought too if it comes down to that. 

[Howard_Casto]

AC to AC Wall Adapter Transformer 16 Volt @ 1000mA Black Straight 2.1mm Female Plug

Sorry for the dumb question, but is it the mA that I can "overshoot?" I did this once for an old NES, but couldn't remember if it was the voltage or the milliamps.

Sent from my Atari 2600

You want the voltage to be in the proper range and the amperage to be equal or greater than.  The device will pull as much juice as it needs.  Proper voltage will ensure that it cannot try to pull too much at once and thus fry something.

^^This^^

The question really comes down to how flexible the device is in terms of voltage.  Most things will work with a volt or two in either direction. 

[acvieluf]

Take a look at the schematic:


http://www.atarimuseum.com/videogames/dedicated/videomusic/vm-sidea.jpg

You can bypass the AC adapter entirely and feed DC voltage to the test points on the board.  Looks like you need -9V (TP3), -5V (TP1), and +8V (TP2).  Playing with a 12V supply, some resistors, and an inverter circuit should coax all those out.

Haha, I really appreciate the input. This project may take a LONG TIME to learn enough to do anything with, beyond the power adapter.

Sent from my Atari 2600

[pbj]

Look at the bottom of the page where it says POWER.  Basically what's happening there is 14V AC is being rectified into DC current, and then chopped into the three voltages you need.  The circuit board will have three posts sticking off of it where you can measure to make sure all the proper voltages are being fed to the rest of the device.  (these test points are there for diagnostics because these circuits run hot and parts burn out)

My proposal is that you ignore the AC part of this setup, and directly connect another power supply to those test points.

Anyway, I'm pretty sure I've got either a 12V or 14V transformer laying around.  It was yanked out of a stereo.

[pbj]

Look at what I got....



 

Feel comfortable wiring this up?

[acvieluf]

Look at what I got....



 

Feel comfortable wiring this up?

HAHA!  I definitely deserve that.  I can wire this up.  Even with this, i'd have questions.    But i can do it! 

What do you want for it?

[pbj]

Free.  Send me your address and I'll mail it tomorrow morning.

 

[acvieluf]

Free.  Send me your address and I'll mail it tomorrow morning.

 

Wow, thanks! Pm incoming!

Sent from my Atari 2600

[yotsuya]

That Jim is a classy guy. I tell you what, I'm sending you your stickers tomorrow.

[Howard_Casto]

He has his moments. 

Btw.... I was thinking man, you should do a youtube channel of popular songs on the AVM, like people do with those floppy organs.  I would subscribe. 

[pbj]

Power supply is on its way to Canada.  The black and white wires are your AC input, the two blue wires are your 14V output.  I tested it and you should be good to go.

[acvieluf]

He has his moments. 

Btw.... I was thinking man, you should do a youtube channel of popular songs on the AVM, like people do with those floppy organs.  I would subscribe.

Hmmm....now that's an idea!

Sent from my Atari 2600

[pbj]

So.... transformer arrive?

[Howard_Casto]

Also I demand a video of this thing in action.

[acvieluf]

So.... transformer arrive?

It did!  I wasn't trying to be rude in not replying here yet.  I have been out of town off and on lately, but was planning on posting here when i got back to work on it this next week!

The TMNT magnets were awesome, what a sweet bonus!

Thanks, and i'll post a bit more when i get back.

 

[acvieluf]

So after the loooong delay, i was able to pick this back up.  It took me about an hour looking at the schematic, and the wiring to be confident enough to wire it up without blowing it up.  I connected it up, and viola!  No smoke or sparks!  Then i realized that the video output requires an RF adapter.  I have one kicking around, so the search is on.  Here's a pic to prove this little side project isn't dead.


Also, now that i'm sitting down with a little more time, thank you again, pbj, for the transformer and the magnets.  My 5 year old daughter (who loves ms. pac-man) nabbed your postcard before i saw it.  That took some swift "hey, look over there", type hiding. haha.

the x's and o's were a nice touch   

[Locke141]

[pbj]

Yeah, despite all his diagnostic toosl, he just shotgun replaces a bunch of parts until it works IIRC.

[Howard_Casto]

Eh it's a million years old. That's probably what I would have done just to be on the safe side.  I have no clue why I'm defending Ben Heck.... I'm not exactly a fan. 

I think acvieluf is trying to beat me on my slowness record.  We want vids man, pick up the pace. 

[acvieluf]

I think acvieluf is trying to beat me on my slowness record.  We want vids man, pick up the pace. 

Haha, yes I'm aware I'm being slow. However, I have located an RF adapter, and should be back to testing it tomorrow. Although I think a video at this point will probably be just a blank screen. Just a hunch, 

So simmer down now. 

Sent from my Atari 2600

[acvieluf]

Welp, as promised, an action photo.

Looks like I'm going to NEED a multimeter. I was hoping to get lucky... : /



Sent from my Atari 2600