Tech: Can I replace Pwr Supply with Computer Supply?

[Taxman]

Archived from groups: rec.games.video.arcade,rec.games.video.arcade.collecting (More info?)

I have a Super Cobra cocktail that someone did a butcher job on, I don't
even want to go into the mess. The power supply is a transformer block that
supplies isolated 110 to a GO7, 6.3 volts to some general illumination, and
what is suppose to be a 10 vac and 15 vac lines to the regulator board. The
regulator board supplies +5 vdc, -5 vdc, +12 vdc, +12 vdc unregulated to the
harness.

I have old computers all over the place. Can I just take AC after the
switch and run the monitor through an isolation transformer and a regular
computer type power supply for the rest of the voltages? I know there are
+5 and +12. I will have to find out about the -5. What is the reason for
+12 vdc unregulated? Is this needed? And I should be able to run GI off a
5V line.

This old Stern regulator board is butchered and burnt. What is my best bet?

Thanks in advance - Dave

 

[Guest]

Archived from groups: rec.games.video.arcade,rec.games.video.arcade.collecting (More info?)

You would probably need to use an older style AT power supply, but it
does work. The PS would provide both +/- 5v and +/-12V. I remember
reading somewhere that it's not an ideal solution, because (iirc) the
Computer PS puts out 20 amps on the +5v and the typical arcade PS puts
out much less (3 amps?) but I could be wrong on that. Doing a google
search will probably answer that.

On most older PC Power supplies (at least on the old AT ones), the
outputs (to the motherboard)are as follows:
Pin Funtion Wire color

1. Power Good * Orange
2. +5Vdc Red
3. +12Vdc Yellow
4. -12Vdc Blue
5. Ground Black
6. Ground Black

7. Ground Black
8. Ground Black
9. -5Vdc White
10. +5Vdc Red
11. +5Vdc Red
12. +5Vdc Red

It's a pretty safe bet that the colors listed are correct, but (from
what I understand)there is no technical standard for this, although I
personally have never seen one that doesn't follow this color pattern.
Of course, I can't guarantee any of this will work, or that you won't
fry your board

 

[Guest]

Archived from groups: rec.games.video.arcade,rec.games.video.arcade.collecting (More info?)

Supplying MORE amps is safe. Supplying too few amps is DANGEROUS. Exactly
why so many people burn down their houses with extention cords.

E.g. Your typical house wiring can supply 15 amps at an outlet using 14
gauge romex wire. Plug a 120 watt 25" TV into it, and you use (appx) 1 amp.
The TV doesn't get harmed just because you can supply 15 amps.

On the other hand, plug 2 1850 watt heaters into an outlet and watch your
walls catch on fire as it tries to pull 30+ amps through a 15 amp wire.

"RedWolfJC" <redwolfjc@excite.com> wrote in message
news:1113969614.843316.151130@g14g2000cwa.googlegroups.com...
> You would probably need to use an older style AT power supply, but it
> does work. The PS would provide both +/- 5v and +/-12V. I remember
> reading somewhere that it's not an ideal solution, because (iirc) the
> Computer PS puts out 20 amps on the +5v and the typical arcade PS puts
> out much less (3 amps?) but I could be wrong on that. Doing a google
> search will probably answer that.
>
> On most older PC Power supplies (at least on the old AT ones), the
> outputs (to the motherboard)are as follows:
> Pin Funtion Wire color
>
> 1. Power Good * Orange
> 2. +5Vdc Red
> 3. +12Vdc Yellow
> 4. -12Vdc Blue
> 5. Ground Black
> 6. Ground Black
>
> 7. Ground Black
> 8. Ground Black
> 9. -5Vdc White
> 10. +5Vdc Red
> 11. +5Vdc Red
> 12. +5Vdc Red
>
> It's a pretty safe bet that the colors listed are correct, but (from
> what I understand)there is no technical standard for this, although I
> personally have never seen one that doesn't follow this color pattern.
> Of course, I can't guarantee any of this will work, or that you won't
> fry your board
>

 

[Taxman]

Archived from groups: rec.games.video.arcade,rec.games.video.arcade.collecting (More info?)

All set and it works great. I sat in my garage tonight and played my first
game of Super Cobra on a cocktail in 22 years.


"Taxman" <NOSPAMdavid.tkacs@snet.net> wrote in message
news:IAj9e.1840$L03.1723@newssvr17.news.prodigy.com...
> I have a Super Cobra cocktail that someone did a butcher job on, I don't
> even want to go into the mess. The power supply is a transformer block
that
> supplies isolated 110 to a GO7, 6.3 volts to some general illumination,
and
> what is suppose to be a 10 vac and 15 vac lines to the regulator board.
The
> regulator board supplies +5 vdc, -5 vdc, +12 vdc, +12 vdc unregulated to
the
> harness.
>
> I have old computers all over the place. Can I just take AC after the
> switch and run the monitor through an isolation transformer and a regular
> computer type power supply for the rest of the voltages? I know there are
> +5 and +12. I will have to find out about the -5. What is the reason for
> +12 vdc unregulated? Is this needed? And I should be able to run GI off
a
> 5V line.
>
> This old Stern regulator board is butchered and burnt. What is my best
bet?
>
> Thanks in advance - Dave
>
>
>
>

 

[Guest]

Archived from groups: rec.games.video.arcade,rec.games.video.arcade.collecting (More info?)

In rec.games.video.arcade.collecting anonebayseller <anon@seller.com> wrote:
: Supplying MORE amps is safe. Supplying too few amps is DANGEROUS. Exactly
: why so many people burn down their houses with extention cords.

Uh... those 2 have nothing to do with each other.

A weaker power supply that doesn't supply as much current as the PCB
requires will either shutdown gracefully or just brown out and supply
lower voltages. (Which can lead to runaway since the lower voltage
might make the board draw more current, until something shuts down all
the way).

In house wiring, there's a virtually unlimited supply of current,
but the 14ga romex is only rated at 15A, so if you're trying to supply
significanltly more through it, it'll heat up due to resistive losses,
and the resistivity increases, causing more voltage drop in the wire,
and since there's unlimited current available, the runaway doesn't stop
untilthe wire get hot enough to set surrounding things aflame.

: On the other hand, plug 2 1850 watt heaters into an outlet and watch your
: walls catch on fire as it tries to pull 30+ amps through a 15 amp wire.

No, you watch your circuit breaker pop or fuse blow

--
Mark Spaeth mspaeth@mtl.mit.edu
50 Vassar St., #38.265 mspaeth@mit.edu
Cambridge, MA 02139
(617) 452-2354 http://rgvac.978.org/~mspaeth

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

What dismal PS those Stern games had. Were switchers that expensive back
then? Why bother making your own was it that much cheaper than buying a
couple thousand switchers? I can vouch for the over drawing wiring
thing, my helper attached thermostat wire to 220v. It was a real treat
having the insulation melt then the red hot wire burn my hand!

 

[Guest]

Archived from groups: rec.games.video.arcade,rec.games.video.arcade.collecting (More info?)

Want a quick example... go and grap hold of both sides of a car battery...
fell anything? I would highly doubt it as you have 12 volts / 100,000 ohms
which results in negligable current flow...

Now take a screw driver (don't really do this!) and short it across the
terminals... you'll instantly weld the screw driver to the battery (and
probably explode the battery in your face as soon as all the hydrogen
outgassing from the reaction ignites!).

The supply you get from a wall is constant voltage... with the voltage fixed
(wall or switcher output) and the resistance fixed (game board), the only
thing that is variable is current flow, which WILL vary depending on the
other two. This is why people say it will only draw what it needs.

There ARE such things as constant current sources which will supply a fixed
current. In such a case, it is the output voltage that varies. Such a
source is used in very specific circumstances and you would know if you were
using one (hopefully). (anyone else(sheepishly) ever blow up something in
the lab by accidently hitting constant current on a supply by mistake?).

steve

"RedWolfJC" <redwolfjc@excite.com> wrote in message
news:1113969614.843316.151130@g14g2000cwa.googlegroups.com...
> You would probably need to use an older style AT power supply, but it
> does work. The PS would provide both +/- 5v and +/-12V. I remember
> reading somewhere that it's not an ideal solution, because (iirc) the
> Computer PS puts out 20 amps on the +5v and the typical arcade PS puts
> out much less (3 amps?) but I could be wrong on that. Doing a google
> search will probably answer that.
>
> On most older PC Power supplies (at least on the old AT ones), the
> outputs (to the motherboard)are as follows:
> Pin Funtion Wire color
>
> 1. Power Good * Orange
> 2. +5Vdc Red
> 3. +12Vdc Yellow
> 4. -12Vdc Blue
> 5. Ground Black
> 6. Ground Black
>
> 7. Ground Black
> 8. Ground Black
> 9. -5Vdc White
> 10. +5Vdc Red
> 11. +5Vdc Red
> 12. +5Vdc Red
>
> It's a pretty safe bet that the colors listed are correct, but (from
> what I understand)there is no technical standard for this, although I
> personally have never seen one that doesn't follow this color pattern.
> Of course, I can't guarantee any of this will work, or that you won't
> fry your board
>

 

[Guest]

Archived from groups: rec.games.video.arcade,rec.games.video.arcade.collecting (More info?)

"Mark C. Spaeth" <mspaeth@plancherel.mit.edu> wrote in message
news:42671698$0$567$b45e6eb0@senator-bedfellow.mit.edu...
> In rec.games.video.arcade.collecting anonebayseller <anon@seller.com>
> wrote:
> : Supplying MORE amps is safe. Supplying too few amps is DANGEROUS.
> Exactly
> : why so many people burn down their houses with extention cords.
>
> Uh... those 2 have nothing to do with each other.

It certainly does.. people try to connect too much amp draw to 16 ga or 18
gauge extension wire... they're trying to pull too many amps through the
wire that cannot supply it.


> : On the other hand, plug 2 1850 watt heaters into an outlet and watch
> your
> : walls catch on fire as it tries to pull 30+ amps through a 15 amp wire.
>
> No, you watch your circuit breaker pop or fuse blow

Not for those homes that put in 20 amp breakers on 15 amp wire or pennies in
their fuse box because they're "sick of the constant blows", or have 16
gauge old fashioned wire on a 15 or 20 amp fuse/breaker.


>
> --
> Mark Spaeth mspaeth@mtl.mit.edu
> 50 Vassar St., #38.265 mspaeth@mit.edu
> Cambridge, MA 02139
> (617) 452-2354 http://rgvac.978.org/~mspaeth
>

 

[Guest]

Archived from groups: rec.games.video.arcade,rec.games.video.arcade.collecting (More info?)

"anonebayseller" <anon@seller.com> wrote in message
news:116fqk9q6sb1i23@corp.supernews.com...
>
> "Mark C. Spaeth" <mspaeth@plancherel.mit.edu> wrote in message
> news:42671698$0$567$b45e6eb0@senator-bedfellow.mit.edu...
> > In rec.games.video.arcade.collecting anonebayseller <anon@seller.com>
> > wrote:
> > : Supplying MORE amps is safe. Supplying too few amps is DANGEROUS.
> > Exactly
> > : why so many people burn down their houses with extention cords.
> >
> > Uh... those 2 have nothing to do with each other.
>
> It certainly does.. people try to connect too much amp draw to 16 ga or 18
> gauge extension wire... they're trying to pull too many amps through the
> wire that cannot supply it.

Mark's right... You said that "Supplying MORE amps is safe. Supplying too
few amps is DANGEROUS". In your extension wire example your "supply" of
current is very large (~200A+ from the house mains, or limited to 15-20A
continuous by a breaker/fuse). The problem is that the wire is not capable
of delivering the amount of current you're trying to draw without excessive
heating/resistance.

The "supply of amps" isn't necessarily the problem, it's the capability of
the wire that it's used to connect to the power supply that can get you.

So if you have a game PCB that draws 5A on +5VDC. You could:

a) Have a +5VDC supply rated for 10A and be fine.
b) Have a +5VDC supply rated for 200A and be fine.
c) Have a +5VDC supply rated for 1A and kill the supply (or have it
shutdown)
d) Have a +5VDC supply rated for 200A and connect it with a few strands of
30ga wire-wrap wire and start a fire.

Current rating alone is not sufficient to say "safe" or "dangerous"...

-Clay

 

[Vaxx]

Archived from groups: rec.games.video.arcade,rec.games.video.arcade.collecting (More info?)

This is why people say it will only draw what it needs.
>
> There ARE such things as constant current sources which will supply a
fixed
> current. In such a case, it is the output voltage that varies. Such a
> source is used in very specific circumstances and you would know if you
were
> using one (hopefully). (anyone else(sheepishly) ever blow up something in
> the lab by accidently hitting constant current on a supply by mistake?).
>
> steve
>

just the ends of some multi probes Had it set on amps when checking the
voltage on 240v ac !!

 

[Guest]

Archived from groups: rec.games.video.arcade,rec.games.video.arcade.collecting (More info?)

Lol... that'll do it... not that *I* have ever done anything like that... of
course I buy boxes of those $2.99 multi-testers for a reason
(actually... they're so damn cheap nowadays it's really hard to justify
buying a $200 fluke).

"VaxX" <geoff_gunn@hotmail.com> wrote in message
news:42678a29$0$261$61c65585@uq-127creek-reader-03.brisbane.pipenetworks.com.au...
> This is why people say it will only draw what it needs.
>>
>> There ARE such things as constant current sources which will supply a
> fixed
>> current. In such a case, it is the output voltage that varies. Such a
>> source is used in very specific circumstances and you would know if you
> were
>> using one (hopefully). (anyone else(sheepishly) ever blow up something
>> in
>> the lab by accidently hitting constant current on a supply by mistake?).
>>
>> steve
>>
>
> just the ends of some multi probes Had it set on amps when checking the
> voltage on 240v ac !!
>
>
>

 

[Guest]

Archived from groups: rec.games.video.arcade,rec.games.video.arcade.collecting (More info?)

In rec.games.video.arcade.collecting anonebayseller <anon@seller.com> wrote:
:
: "Mark C. Spaeth" <mspaeth@plancherel.mit.edu> wrote in message
: news:42671698$0$567$b45e6eb0@senator-bedfellow.mit.edu...
:> In rec.games.video.arcade.collecting anonebayseller <anon@seller.com>
:> wrote:
:> : Supplying MORE amps is safe. Supplying too few amps is DANGEROUS.
:> Exactly
:> : why so many people burn down their houses with extention cords.
:>
:> Uh... those 2 have nothing to do with each other.
:
: It certainly does.. people try to connect too much amp draw to 16 ga or 18
: gauge extension wire... they're trying to pull too many amps through the
: wire that cannot supply it.

That's a matter of current DRAW, not current SUPPLY.

:
:> : On the other hand, plug 2 1850 watt heaters into an outlet and watch
:> your
:> : walls catch on fire as it tries to pull 30+ amps through a 15 amp wire.
:>
:> No, you watch your circuit breaker pop or fuse blow
:
: Not for those homes that put in 20 amp breakers on 15 amp wire or pennies in
: their fuse box because they're "sick of the constant blows", or have 16
: gauge old fashioned wire on a 15 or 20 amp fuse/breaker.


Even my 200+ year old house has breakers. (Of course, the moron who wired it
up put the entire 2nd floor on a single circuit, so....) No house wired to
modern code will have 16 ga wire on a 15/20A breaker. There's no accounting
for stupid people swapping breakers, shorting fuses, etc though.




--
Mark Spaeth mspaeth@mtl.mit.edu
50 Vassar St., #38.265 mspaeth@mit.edu
Cambridge, MA 02139
(617) 452-2354 http://rgvac.978.org/~mspaeth

 

[Guest]

Archived from groups: rec.games.video.arcade.collecting (More info?)

Mark you would be suprised how many houses in the Boston area namely
Needham / Newton area have 60A services with screw in fuses. I can't
imagine only having 60A in my house. You should NEVER use a penny to
jump a fuse...use a nickle, they work much better!! :^)