(After Market) C64 PSU on an Atari 800xl?

[DistantStar001]

Ok.  First I'm not crazy.  There is no way that I am going to plug in a Commodore PSU straight into my Atari.  I know that would kill it.  But at the moment, all I have is an original ingot, which as I understand it is no safer than the original Commodore units.  Currently, my C64s are using an after market PSU I got from Ray Carlson, which provides a consistent 5.2v at 3 amps.  Now I'm curious if I could build an extender for the 5v DC rails without the 9v AC.  

Basically, a female 7 pin din connector extending the 5v and ground on pins 5 and 2 to pins 1, 4, and 6, and to pins 3, 5, and 7 respectively, on a male 7 pin din on the other side.  If I'm right, the 9v AC would dead end, while the 5v DC would pass through to the Atari.  My questions are: Has any one ever tried this before?  And would this be safe for my Atari?

[_The Doctor__]

chop off everything but the 5.2 volts line and ground and wire it up to the wires of the Atari connector you chopped off the ingot... boom done only 2 wires involved

 

Edited February 22, 2021 by _The Doctor__

[+Nezgar]

I would keep the C64 PSU as far away from your atari as possible... even with an adapter...

 

Use your efforts to splice a DIN connector onto a USB cable and use a 2.0+amp phone charger instead. This will be much more useful.

 

Edit: yes I agree with @_The Doctor__ - use the cutoff DIN pigtail from the ingot to attach to a USB connector

[DistantStar001]

31 minutes ago, Nezgar said:

Use your efforts to splice a DIN connector onto a USB cable and use a 2.0+amp phone charger instead.

I tried something similar as a two brick solution for my C64, but no matter which USB brick I used, the 5v lines would drop to 3v under load.  Maybe the wires in the USB cable I used were too thin?  

 

That's my thinking anyway, since all the USB bricks I tried still manage to charge my tablets and iPods.  

 

Maybe the Atari has lower power demands?  I'll give it a try.  Under Volting the system shouldn't be too much of a problem as long as it's only for a few seconds.

 

In any case, if you've done this, what USB brick did you use?  Maybe yours are better than mine.

Edited February 22, 2021 by DistantStar001
Additional information/Question

[DistantStar001]

31 minutes ago, _The Doctor__ said:

chop off everything but the 5.2 volts line and ground and wire it up to the wires of the Atari connector you chopped off the ingot... boom done only 2 wires involved

The problem here is that I still need a PSU for my C64s.  But in essence, what you're suggesting would basically do the same thing, just earlier in the power line.  

[Mazzspeed]

Um...

 

Couldn't you just grab a 7 pin Male DIN and a 7 PIN Female DIN and wire up an adapter as follows:

 

C64 PSU   >   A8

============================

PIN 1      >      PIN 3 (GND)

PIN 2      >      PIN 5 (GND)

PIN 3      >      PIN 7 (GND)

PIN 5      >      PINS 1,4 & 6 (+5v DC)

 

Because that Ray Carlson PSU would literally crap out Chinesium wall warts for breakfast.

[+Nezgar]

2 hours ago, DistantStar001 said:

I tried something similar as a two brick solution for my C64, but no matter which USB brick I used, the 5v lines would drop to 3v under load.  Maybe the wires in the USB cable I used were too thin?  

The thin wires would definitely be a factor, but I've seen only dropping to about 4.5V... anyhow, the cord on the ingot PSU is 18AWG I think. Much thicker.

[Sugarland]

At the very least, be sure to label the DIN plug end of the cord for the C64 wire so you don't accidentally plug it into the 800XL. For the XL power cord, a decent gauge USB cord should work but shorter is better.

[+skr]

5 hours ago, DistantStar001 said:

I tried something similar as a two brick solution for my C64, but no matter which USB brick I used, the 5v lines would drop to 3v under load.  Maybe the wires in the USB cable I used were too thin?  

 

That's my thinking anyway, since all the USB bricks I tried still manage to charge my tablets and iPods.  

 

Maybe the Atari has lower power demands?  I'll give it a try.  Under Volting the system shouldn't be too much of a problem as long as it's only for a few seconds.

 

In any case, if you've done this, what USB brick did you use?  Maybe yours are better than mine.

I´m using an EasyAcc 15000mAh which also powers four GoPros at once. The cable I use was once built by @tf_hh, so I don´t actually know anything about thickness of wires.

[Mazzspeed]

10 minutes ago, Sugarland said:

At the very least, be sure to label the DIN plug end of the cord for the C64 wire so you don't accidentally plug it into the 800XL. For the XL power cord, a decent gauge USB cord should work but shorter is better.

A good recommendation.

 

Any Ray Carlson PSU will power two C64's and an A8 at the same time with no drop in voltage whatsoever. It's not that hard to make a short adapter harness, furthermore it would cost less than buying any half decent USB PSU.

Edited February 22, 2021 by Mazzspeed

[TGB1718]

6 hours ago, DistantStar001 said:

I tried something similar as a two brick solution for my C64, but no matter which USB brick I used, the 5v lines would drop to 3v under load.  

It usually says on the USB charger what the rated current is, a lot of older phone chargers were 1 AMP or less, so not sufficient for an 800XL

A 2 AMP would be fine though.

I use Raspberry Pi USB PSU's as they tend to be less noisy and were built for this purpose.

[_The Doctor__]

the crappy usb cords are a big issue, running an Atari in brownout level supply is hard on the chips. The other issue with many usb wall supplies is simply how dirty the power is, noise and ripple.. most of them are only designed to pulse charge a battery and let the phone/battery + circuit combo act as a filter. If you really have to, try to stick with only the best of the USB supplies or any of the great power supplies we already have or are made today... USB wall, and buck converter type supplies are a crap shoot, as are the usb wires... some wires put out 5.2 without a hitch, others on the same stuff put out 4.5 which is terrible! .7 drop!

Edited February 22, 2021 by _The Doctor__

[Mclaneinc]

As you said, be careful as the C64 has versions as deadly as the ingot..Test the voltage under load

[+ZuluGula]

I don't understand why so many people insist on using questionable quality power supplies or chargers, when Atari uses only 5V DC and 1.5-2A is enough for most of setups. You can get brand new Raspberry Pi or MeanWell PS for under $15.

[manterola]

This stuff is useful for building an Atari 8 bit power supply:

https://www.ebay.com/itm/3ft-USB-Power-Cable-2-Wire-USB-2-0-Male-Charging-Cord-Extension-DIY-with-Switch/383775457710

https://www.ebay.com/itm/30CM-50CM-100CM-USB-LED-Connector-Cable-line-2pin-USB-Socket-Power-Connect-Wire/264706069951

 

Not sure about the maximum current but I got more copper than any typical USB cable.

[TGB1718]

1 hour ago, ZuluGula said:

You can get brand new Raspberry Pi or MeanWell PS for under $15.

As I said also in post #11, it's really a no brainer, cut the lead off your Ingot, solder the lead onto one of these, job done

[Mazzspeed]

4 hours ago, Mclaneinc said:

As you said, be careful as the C64 has versions as deadly as the ingot..Test the voltage under load

He's not using the standard C64 power brick, he's using an aftermarket Ray Carlsen PSU.

 

I still use the standard C64 PSU, not the epoxy filled one. It's the same one I had as a kid and it's never missed a beat. One of these days I'll replace it.

[Mclaneinc]

Ah, missed that bit...Age / senile

[DistantStar001]

So I ended up going with the USB adapter for now.  It seems to work well with my spare iPad charger.  Which is nice since I can attach it to a longer power cord and not be so closely tethered to the wall.  I might try to build the adapter for my Ray Carlson PSU some day, but for now, this works!  Also, the video output has never looked better.  

 

Thanks to all for your help and liberating me from that ingot!  

 

[Mazzspeed]

On 2/24/2021 at 4:50 AM, Mclaneinc said:

Ah, missed that bit...Age / senile

I'm not far behind you my friend! I forget people's names two minutes after I've met them....

 

Perhaps that's selective. ?

[Mclaneinc]

I'm saying nothing

[Rybags]

I'm in the "don't see the point" camp.

 

Another point is that the 9V AC going unused mightn't be healthy - it would be nice if that could be used on a 1050 but I highly doubt the amperage would be what's needed there.

 

In any case, plenty of USB power supplies in the 1-2 Amp range for cheap that can do the job if you make up a cable.

On that note though - I've got some microUSB breakout boards that could easily be made into suitable adaptors with a DIN plug at the other end.

[DistantStar001]

On 2/26/2021 at 4:51 AM, Rybags said:

it would be nice if that could be used on a 1050 but I highly doubt the amperage would be what's needed there.

I have thought of making an adapter for my VIC-20 bricks.  I made the opposite toggle for my 1050 PSU some time back, but it didn't end well for the PSU (I guess the VIC was too much for it).  Since then, I've been using the PSU from my old cable-box.  It works, but I don't entirely trust it.  

I've since gotten several original VIC-20 bricks and they seem a lot beefier (10v 3amp) than their late Atari counterpart.  It seems that a simple barrel adapter should work.  Best part would be that two of them are the larger early versions.  The bottoms are held on with screws, making them serviceable if needed.  

Or I could just add a second cord with a barrel jack for the 1050.  But then I'd have an unused cord dangling off the brick.  So...  Maybe not.