Best power supply to use with Atari 800?

[TapperP]

So I recently got an Atari 800 and it came with the original power supply. It looks like the one in the photo below. I was just reading that old power supplies can kill the motherboard if they go bad, so what is a recommended new power supply I can buy for the Atari 800? If you have a store link that would be much appreciated. I really don't want anything bad to happen to this computer!
 

Edited June 20, 2020 by TapperP

[+DrVenkman]

8 minutes ago, TapperP said:

So I recently got a Atari 800 and it came with the original power supply. It looks like the one in the photo below. I was just reading that old power supplies can kill the motherboard if they go bad, so what is a recommended new power supply I can buy for the Atari 800? If you have a store link that would be much appreciated. I really don't want anything bad to happen to this computer!
 

The original 9VAC power bricks for the 400/800/1050/1200XL are dead simple transformers - there's not much inside to go wrong, and when they fail, it's either because the fuse inside blew (probably because it was subject to a power surge from house wiring), or because the thing was physically abused and something broke the transformer coil windings. If you have a multimeter, test the PSU and see what the output is. Since it's unregulated, you should get something like 10.5 - 11VAC out of it without a load. That's perfectly fine and expected. 

 

I have about a dozen of these and all of them are still fine after 35 - 40 years. 

[BillC]

8 minutes ago, TapperP said:

So I recently got a Atari 800 and it came with the original power supply. It looks like the one in the photo below. I was just reading that old power supplies can kill the motherboard if they go bad, so what is a recommended new power supply I can buy for the Atari 800? 

 

The 800 has a power supply board to convert the 9VAC from the power supply to the 3 DC voltages required by the system, these power supplies are just a transformer and fuse.

It's some versions the 5VDC power supplies used with the 600XL/800XL and XE computers that tend to fail and damage chips.

[TapperP]

4 minutes ago, DrVenkman said:

The original 9VAC power bricks for the 400/800/1050/1200XL are dead simple transformers - there's not much inside to go wrong, and when they fail, it's either because the fuse inside blew (probably because it was subject to a power surge from house wiring), or because the thing was physically abused and something broke the transformer coil windings. If you have a multimeter, test the PSU and see what the output is. Since it's unregulated, you should get something like 10.5 - 11VAC out of it without a load. That's perfectly fine and expected. 

 

I have about a dozen of these and all of them are still fine after 35 - 40 years. 

Ah, great to know. Maybe what I was reading was referencing other Atari AC adapters then.

 

Just now, BillC said:

The 800 has a power supply board to convert the 9VAC from the power supply to the 3 DC voltages required by the system, these power supplies are just a transformer and fuse.

It's some versions the 5VDC power supplies used with the 600XL/800XL and XE computers that tend to fail and damage chips.

Thank you.

 

Well, then never mind I guess. 😛

Edited June 20, 2020 by TapperP

[Paul Westphal]

I use these : https://www.8bitclassics.com/product/atari-400-800-1050-ac-adapter/

[TapperP]

3 minutes ago, Paul Westphal said:

I use these : https://www.8bitclassics.com/product/atari-400-800-1050-ac-adapter/

Thanks for the link. I may not really need one, but I still might buy one just for the smaller size alone.

[BillC]

3 hours ago, Paul Westphal said:

I use these : https://www.8bitclassics.com/product/atari-400-800-1050-ac-adapter/

I don't recommend these, they have a limited output current, only ~1.5A. This is about the same a the CO14319 which came with my first 400, the fuse in that power supply blew after I upgraded the 400 with a Mosaic 64K board.

 

It may work OK with a 400 or 800, but definitely won't supply sufficient current for a 810/1050/XF551 drive, I will only use a CO14319 with an 850 or a stock 400 due to this low current rating.

 

There were several 9VAC power supplies from Atari, the CO17945(31VA) is the most common.

[Gavin1968]

On 6/20/2020 at 4:03 PM, TapperP said:

I was just reading that old power supplies can kill the motherboard if they go bad,

I am still using mine from my first Atari 800 that my dad bought me when I was 10, and I am 51 now! These are rock solid.

 

[gilsaluki]

1 hour ago, Gavin1968 said:

I am still using mine from my first Atari 800 that my dad bought me when I was 10, and I am 51 now! These are rock solid.

 

I have only had one go "bad" on me in all these years.   It was used for my disk drive.   I opened it, caution is advised, and replaced the blown fuse.  Used it for another 10 or so years till it finally developed an open Primary winding.  

[Gavin1968]

2 hours ago, gilsaluki said:

 I opened it

I found that is the most difficult part, getting that darn case split open! LOL 

 

[TGB1718]

49 minutes ago, Gavin1968 said:

I found that is the most difficult part, getting that darn case split open! LOL 

Mine was held by rivets, so drilled them out, replaced the fuse and fitted screws/nuts, still working fine