CV AC Adapter Hack?

[unhuman]

Any reason why I couldn't replace the huge CV AC adapter with smaller ones for 5V and 12V? Certainly seems like a new power source would be far more efficient... And I might be able to embed the new adapters inside the CV for a far cleaner look. The only thing I wonder is what are the amperage requirements of each of the power lines?

Edited January 2, 2011 by unhuman

[+5-11under]

Sounds good. Don't forget the minus 5 volts.

[unhuman]

Yeah - just would like to know minimum amperages... Or maybe I'll just have to see if what I have is "good enough"

[Yurkie]

Yeah - just would like to know minimum amperages... Or maybe I'll just have to see if what I have is "good enough"

 

The maximum amperage rating for the original power supply is on the data plate. I wouldn't use anything that is rated lower than that.

[NIAD]

Any reason why I couldn't replace the huge CV AC adapter with smaller ones for 5V and 12V? Certainly seems like a new power source would be far more efficient... And I might be able to embed the new adapters inside the CV for a far cleaner look. The only thing I wonder is what are the amperage requirements of each of the power lines?

This system is on eBay right now and includes a lot of modifications as well as an internal power supply!

 

eBay Auction -- Item Number: 190485230381

[Murph74]

Wow-- that Ebay seller is a modding phewl! Looks like he does some nice work across multiple systems!

 

Also, there are a few threads here about doing internal power mdos on the CV if you search for them. I think one even has a link to a $20 solution if you're inclined to do it yourself. (It's possible that was a google search that I saw that on, not here-- it's early here, brain is still hazy!)

Edited January 3, 2011 by Murph74

[Ikrananka]

Wow-- that Ebay seller is a modding phewl! Looks like he does some nice work across multiple systems!

 

Also, there are a few threads here about doing internal power mdos on the CV if you search for them. I think one even has a link to a $20 solution if you're inclined to do it yourself. (It's possible that was a google search that I saw that on, not here-- it's early here, brain is still hazy!)

I have modded a CV with an internal power supply and it works great. I am in the process of ordering a more appropriate power entry module and insulated mounting hardware. Once I have the setup sorted I will be updating my internal power mod thread with full details of how to do the mod and where to buy the parts.

[Ikrananka]

Any reason why I couldn't replace the huge CV AC adapter with smaller ones for 5V and 12V? Certainly seems like a new power source would be far more efficient... And I might be able to embed the new adapters inside the CV for a far cleaner look. The only thing I wonder is what are the amperage requirements of each of the power lines?

This system is on eBay right now and includes a lot of modifications as well as an internal power supply!

 

eBay Auction -- Item Number: 190485230381

Is the seller someone on AA? Looks like he has sourced a nice replacement power switch - would be nice to know where to buy them.

[the.golden.ax]

I wanna know where he gets PCBs with micro switches for the 5200 controllers on the set he is selling.

 

AX

[boardjunkie]

Any reason why I couldn't replace the huge CV AC adapter with smaller ones for 5V and 12V? Certainly seems like a new power source would be far more efficient... And I might be able to embed the new adapters inside the CV for a far cleaner look. The only thing I wonder is what are the amperage requirements of each of the power lines?

 

To replace the pwr supply all you need is to match the voltages and current requirements. For a stock unit, all 3 voltages are under 1 amp, the 5v just short of at 900ma.

 

If you do the ram replacement with parts that are single (5v) supply (hint: check old 386 computer boards for 16 pin ram chips....they work with slight board modification), you can use one of the switching supplies that were used with external CDRW drives, which are typically 5v and 12v at around 1.5-2a each. The -5 was used only with the triple supply ram chips and is no longer needed. You'd just have to splice the cabling to the original 4 pin connector. I'm not sure, but the whole shot may run off just a single 5v supply unless 12v is used elsewhere, like in the RF section. The video processor does not need 12v. If the op amp composite video mod is done, you'll want that 12v line for that.

[Yurkie]

Any reason why I couldn't replace the huge CV AC adapter with smaller ones for 5V and 12V? Certainly seems like a new power source would be far more efficient... And I might be able to embed the new adapters inside the CV for a far cleaner look. The only thing I wonder is what are the amperage requirements of each of the power lines?

 

To replace the pwr supply all you need is to match the voltages and current requirements. For a stock unit, all 3 voltages are under 1 amp, the 5v just short of at 900ma.

 

If you do the ram replacement with parts that are single (5v) supply (hint: check old 386 computer boards for 16 pin ram chips....they work with slight board modification), you can use one of the switching supplies that were used with external CDRW drives, which are typically 5v and 12v at around 1.5-2a each. The -5 was used only with the triple supply ram chips and is no longer needed. You'd just have to splice the cabling to the original 4 pin connector. I'm not sure, but the whole shot may run off just a single 5v supply unless 12v is used elsewhere, like in the RF section. The video processor does not need 12v. If the op amp composite video mod is done, you'll want that 12v line for that.

 

I think the -5 Volts is used for the controller ports.

[boardjunkie]

Any reason why I couldn't replace the huge CV AC adapter with smaller ones for 5V and 12V? Certainly seems like a new power source would be far more efficient... And I might be able to embed the new adapters inside the CV for a far cleaner look. The only thing I wonder is what are the amperage requirements of each of the power lines?

 

To replace the pwr supply all you need is to match the voltages and current requirements. For a stock unit, all 3 voltages are under 1 amp, the 5v just short of at 900ma.

 

If you do the ram replacement with parts that are single (5v) supply (hint: check old 386 computer boards for 16 pin ram chips....they work with slight board modification), you can use one of the switching supplies that were used with external CDRW drives, which are typically 5v and 12v at around 1.5-2a each. The -5 was used only with the triple supply ram chips and is no longer needed. You'd just have to splice the cabling to the original 4 pin connector. I'm not sure, but the whole shot may run off just a single 5v supply unless 12v is used elsewhere, like in the RF section. The video processor does not need 12v. If the op amp composite video mod is done, you'll want that 12v line for that.

 

 

Also....anyone still using the stock supply should check the output voltges every so often. I had a couple CV's brought in for repair and one of the pwr supplies had a 5v output that was at around 9v. The pass transistor was OK, but the v ref IC was putting out the wrong voltage. I didn't bother to repair it since I did a ram upgrade and could use a modern switching supply. Just FYI....

[the.golden.ax]

Could we expand on the ram chip idea? I have a dozen units with glitchy video.

 

AX

[boardjunkie]

Could we expand on the ram chip idea? I have a dozen units with glitchy video.

 

AX

 

Well you need to be semi-well versed in digital logic repair or hardware design. There are several different types of dynamic ram that can be interchanged with a 4116 that don't need the extra 12 and -5v supplies. A 4164 is a common replacement, but really you can use just about anything that is functionally equivalent with the same pinout....more or less. You just need to eliminate the extra supply voltages so they don't appear at the chip pins that the 4116 needed. And any unused address lines need to be tied either high or low. Consult the datasheet do determine compatibility.

 

I just did ram replacement on 2 CV units and I used ram from an old 386 computer board that was in my junkpile just because it was all I had on hand. 16 pin, part type 2801-07. The pinout was the same as a 4116, save for 2 extra address lines that were unused. The replacement ram uses way less power (cmos based) and has a faster access time. It is a bit overkill, but worked out great. I like to recycle old stuff that would otherwise end up in the trash.

 

 

That reminds me....I have a ton of old arcade hardware that uses 4116 ram that I should dig out and update the ram on. That old Williams stuff (Defender, Joust, Robotron, etc.) was *always* flaky due to the 3 supplies not "coming up" at the same time....causing random errors and failure to get thru self test.