What is this witchcraft? Heresy! 2600 switching power supply modification

[mojoatomic]

It's an itsy bitsy, teeny Weenie little switching power supply that replaces the 7805 voltage regulator giving you a near perfect ripple free 5v, under much broader conditions with less heat than the 7805 EVER thought about. As a bonus, it also gets you a divorce from much of the line noise for a much cleaner picture.

 

 

 

 

Edited February 14, 2017 by mojoatomic

[Cobra Commander]

Go ahead and share with us its name and where you got it please.

[R.Cade]

Just an FYI, you can get these boards to replace 7805's for a couple of bucks on eBay.

[mojoatomic]

Go ahead and share with us its name and where you got it please.

 

TSR 1-2450 - from tracopower; I got mine in a bulk order from Allied

Edited February 14, 2017 by mojoatomic

[R.Cade]

There are these:

http://www.ebay.com/itm/272451377177?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

I have not tried one specifically in a 2600, but have with no problem in other applications. I will try one in a 2600 and report back when I can.

[mojoatomic]

Just an FYI, you can get these boards to replace 7805's for a couple of bucks on eBay.

Please show us a where to find TSR 1-2450's on Ebay for a couple of bucks, I'll buy all they have!

[mojoatomic]

There are these:

http://www.ebay.com/itm/272451377177?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

I have not tried one specifically in a 2600, but have with no problem in other applications. I will try one in a 2600 and report back when I can.

No - they are these....

[R.Cade]

I don't know the internals of the Tracopower, but if it's just a buck converter, see my message above for a clone.

[R.Cade]

Yeah, I'm sure that is just a potted buck converter.

[mojoatomic]

Yeah, I'm sure that is just a potted buck converter.

In all fairness, there's a bit more to it - Traco has been around for a long time and they're well trusted in the industry. They make top notch products and stand behind them. These units have a complete published data sheet with design notes, which is a big deal to guys like me, because I can do my own tests and verify their claims. They also carry a 3 year warranty.

 

All I'm saying is, before you dismiss them out of hand, have a look at the data sheet and compare the long term value.

[R.Cade]

Don't misunderstand. I am not recommending a cheap Chinese knock-off product in place of something from a proven company. I'm just pointing out that they are out there. It could be junk and fry your equipment, or may work fine. It may cause worse interference... I will try one sometime soon and report back.

[mojoatomic]

Don't misunderstand. I am not recommending a cheap Chinese knock-off product in place of something from a proven company. I'm just pointing out that they are out there. It could be junk and fry your equipment, or may work fine. It may cause worse interference... I will try one sometime soon and report back.

I think that is completely reasonable.

[H454]

There is also This:

https://www.digikey.com/product-detail/en/murata-power-solutions-inc/OKI-78SR-5-1.5-W36-C/811-2196-5-ND/2259781

They are also sold on the on 2600 RGB site:

http://etim.net.au/shop/shop.php?crn=206&rn=547&action=show_detail

http://power.murata.com/data/power/oki-78sr.pdf

 

Both the NES and the 2600 RGB kits come with modified power units that replace the 7805.

http://etim.net.au/2600rgb/installation-4switch/19-reg_pins.jpg

 

But the Instructions also have you install a cap as well:

"An extra capacitor is required to reduce radiated noise. Install the supplied 220u electrolytic capacitor between the Input and Ground pins of the switching regulator. The negative leg (marked with a stripe) is connected to ground."

Edited February 15, 2017 by H454

[marcosmeanos]

1) would you use this with a linear or switched mode power wall wart?

 

2) would using a switched mode power supply and a standard 7805 have the same results other than heat output of the regulator?

[mojoatomic]

Either, but a switching supply works better in my opinion.

 

VS switching supply + 7508, this Tracopower unit + switching supply wins as the combo extremely efficient

[tep392]

I'm thinking of changing the 7805 and 7812 over to switching regulators for my 1050 floppy drive. Ever touch the heat sink in one of those? Ouch! I think the large caps next to that heat sink and my floppy's would be happier if I could reduce the internal temperature in the drive.

[marcosmeanos]

Thanks for the reply Mojoatomic. One last thing is did you have to change anything else on the board or is this a true drop in replacement because as H454 mentioned the data sheet talks about adding a capacitor on the input side did you use one?

[Andromeda Stardust]

Hey mojo, i was wondering about the buck regulators... Will these work for any old 5v console that used through-hole 7805 regs? My tg-16 reg got cooked while i was installing an led backlight mod. I hooked up my console brick (nec oem part, which outputs 13v under load) without the sink to test the led board. Got hot as haydes, burnt my finger when i touched it. :-X anyway the thing runs 5.65v at the controller port, a bit high. I could buy a batch of regulators and just redo all my vintage 5v console regulators. My understanding is these do not need sinks, correct?

[mojoatomic]

Hey mojo, i was wondering about the buck regulators... Will these work for any old 5v console that used through-hole 7805 regs? My tg-16 reg got cooked while i was installing an led backlight mod. I hooked up my console brick (nec oem part, which outputs 13v under load) without the sink to test the led board. Got hot as haydes, burnt my finger when i touched it. :-X anyway the thing runs 5.65v at the controller port, a bit high. I could buy a batch of regulators and just redo all my vintage 5v console regulators. My understanding is these do not need sinks, correct?

Yeah, they'll retrofit any 7805 without the use of a heatsink - they just drop right in. Allied has the best price on them as far as I know, and I looked hard. I'm a fan - they really, really work well and just don;t produce any heat at all.

 

On another note... I've looked high and low for for some really high quality 9v switching power supplies - and came up empty. So... I found a manufacturer willing to help me & I'm having them made! I'm really excited about this as I HATE Atari walwarts (always have) as I have seen them eat up more than their fair share of consoles.

[SoundGammon]

Going to put these in my 5200s, 2 is needed I believe, and in my 7800s. Also my Atari 800s!

[mojoatomic]

Thanks for the reply Mojoatomic. One last thing is did you have to change anything else on the board or is this a true drop in replacement because as H454 mentioned the data sheet talks about adding a capacitor on the input side did you use one?

True drop in replacement.

 

Having said that - I would however change out the 40 year old caps as a prophylactic measure - have a look at the schematic, you'll see that 9v is pulled BEFORE it reaches the regulator (blanking delay) on pin 10 of the TIA - that input still needs to be smooth and ripple free. C242 and C243 take care of that. The TSR 1-2450 only requires a (22uf) cap if the input voltage is greater than 32v. The .1uf that it sees won't hurt it at all.

[H454]

Thanks for the reply Mojoatomic. One last thing is did you have to change anything else on the board or is this a true drop in replacement because as H454 mentioned the data sheet talks about adding a capacitor on the input side did you use one?

That extra cap is just for reducing video noise with the 2600 RGB mod.

You probably don't need unless you get interference from higher than normal power draw(like with the RGB mod).

[Andromeda Stardust]

im using a switching 9v 850ma brick from the shack. a Bit Pricey At 20 Bux But Worth It. It runs cooler than the stock bricks and puts 10v unloaded or not. I attached Tips for vcs, Snes, And A Barrel For Nes, Genesis, Turbo, Etc... Most vintage unregulated oem bricks i have tested put out way more juice than the nameplate, loaded or not. This just dumps more heat into the regulator. Suppose the console is pulling 700ma from the regulator with a 12v supply rated 9v on the nameplate. Well theres 7v dropped across the 7805 sinking 700ma, about 5w dumped across a single chip, often with tiny sink attached. The vcs i believe just uses the thin pcb ground plane to dissipate heat, hardly better than air cooling it. And the consoles arent getting any younger...

[marcosmeanos]

Awsome cheers for the info guys.... I joined Atari age to ask about switch mode and It was sat right at the top of the list as most recent post so now it looks as though I will be spending some pennies

[deltronik]

I know very little about these things, but I always heard that switching regulators produce a lot of noise -especially RF- and that the old linear regulators where better in these applications for that reason (I'm guessing that's why etim has the cap in his kit too.)

 

What is it about these that is cleaning up the picture and is there any high pitch noise in the audio after the swap?