An Attempt at a New Power Solution for the Coleco

[nathaniel.lockha]

I came into a couple CVs lately that were lacking controllers and power supplies. Luckily, I had the PSU and controllers already so I could test them, but it annoyed me that I didn't have PSUs to go with them. The current solutions are a bit expensive for my liking, plus I wanted to have something that could run off a normal 'ol 12v supply with a 2.1mm x 5.5mm barrel plug. 

So here it is: a ColecoVision power supply that runs from a single 12v 3a power supply. The 12v is regulated down to 5v with a 7805, and the -5v is achieved with a charge pump inverter. The charge pump is only capable of supplying 100ma of current, but for the VRAM, it's plenty.

I gave it some preliminary testing; leaving it on for a few hours and playing some games of Donkey Kong. Would love to know if it plays nice with some of the other expansions, especially the Roller Controller, given that it uses the power port. 

Anyway, here's the github. Would love to have some thoughts/comments/suggestions on this thing.

[allansim]

I like that it takes a standard supply and can be mounted in the CV.  Great work!

[+-^CrossBow^-]

Wonder if using a dc-dc switcher converter in place of the linear regulator would allow for a smaller amperage 12v source to be used? If this is designed to be installed internally, where is the recommended location? Or is all of that in the github and I just need to go poking around in there a bit LOL.

 

[Captain Cozmos]

If the power supply is changed then have a fork connected to the original plug to supply the Roller Controller with power.
Then remind whomever inherits the thing to never use an original Colecovision power supply.
I will never understand the design choices Coleco Engineers made considering the Atari 2600 out several years earlier had no issues with expansion devices like a track ball.

[Captain Cozmos]

2 minutes ago, -^CrossBow^- said:

Wonder if using a dc-dc switcher converter in place of the linear regulator would allow for a smaller amperage 12v source to be used? If this is designed to be installed internally, where is the recommended location? Or is all of that in the github and I just need to go poking around in there a bit LOL.

 

Personally I would hook up a Chevy V8 with a Holly double pump. But that's me.

[nathaniel.lockha]

20 minutes ago, Captain Cozmos said:

Personally I would hook up a Chevy V8 with a Holly double pump. But that's me.

Ah yes, the oft overlooked Coleco expansion module, the Engine Block

[nathaniel.lockha]

25 minutes ago, -^CrossBow^- said:

Wonder if using a dc-dc switcher converter in place of the linear regulator would allow for a smaller amperage 12v source to be used? If this is designed to be installed internally, where is the recommended location? Or is all of that in the github and I just need to go poking around in there a bit LOL.

 

It's in the github 😊 I've got a pic in there where it's mounted. I designed it though so you could go either way; installing it internally or leaving it on the outside and grafting an original power cable (or newly made one) onto it. I just wanted folks to have the option, and also to keep the cost down.

 

The use of linear regulators is also down to cost - of course, you can use newer, more efficient DC-DC converters (in fact, I did for my first successful build), but it didn't take away from the current needs of the CV.