Hey guys can you tell me if this power supply is broken?
I think it might be but I don't know for sure.
Thanks
Hey guys can you tell me if this power supply is broken?
I think it might be but I don't know for sure.
Thanks
It's probably an unregulated supply. They usually read higher than their nominal voltage when under no load.
OK, you're probably right because I have a couple of them and they are both reading 13-15. But they are also like 30 years old, so I was thinking they could both be broken.
If they are that old then they will not be regulated.
Thanks,
My Atari was actually manufactured in 1970 so I guess they are probably 44 years old. I'm glad they still work.
Good, it is the large capacitors that tend to fail.
and its not very unusual, if a 12v power supply gives you a voltage of 13.5v.
they all have a little "error" of something like 5% or 10%.
but they still work - even after 44 years!
I am surprised to see no regulation, given the fact electronics are sensitive .... it reads dc, so it's at least rectified, what it gets plugged into must have a regulator.
Having seen the inside of an Atari power supply, I can say... the regulation happened somewhere else. IN my case, the only parts inside he power block were transformer, 4 diodes and a 1000 uF capacitor. That will not regulate...
Hi.. WOW, 4 diodes , getting a bit extravagant for a plug pack, must be the DELUXE model..
Tom.....
TomGeorge:
Hi.. WOW, 4 diodes , getting a bit extravagant for a plug pack, must be the DELUXE model..Tom.....
Well it is cheaper than having a larger transformer.
Hmmm... I'm just saying what was there... I know these things were cheap... but there were 4 1N4001's in a bridge configuration... I agree that a lot of these things would just use 1 diode with a filter cap.
Most would use four diodes, in my experience, as an extra 3 diodes are cheaper and smaller than a capacitor that would have to be at least twice as large. And the transformer would have to be larger.
I don't think I've ever seen one of those old power supplies with only one diode.
pwillard:
Hmmm... I'm just saying what was there... I know these things were cheap... but there were 4 1N4001's in a bridge configuration... I agree that a lot of these things would just use 1 diode with a filter cap.
how would that circuit look like ?
isn't using 4 diodes a "minimum" requirement for the rectifier in a power supply (AC to DC) ?
pwillard:
Having seen the inside of an Atari power supply, I can say... the regulation happened somewhere else. IN my case, the only parts inside he power block were transformer, 4 diodes and a 1000 uF capacitor. That will not regulate...
It might be inside the Atari?
Here is the inside of the Atari if you've never seen that. But it was built in 1970.
WOW, look at those solid looking toggle switches !!
nothing like the dinky plastic ones we get nowadays !
retronet_RIMBA1ZO:
pwillard:
Hmmm... I'm just saying what was there... I know these things were cheap... but there were 4 1N4001's in a bridge configuration... I agree that a lot of these things would just use 1 diode with a filter cap.how would that circuit look like ?
isn't using 4 diodes a "minimum" requirement for the rectifier in a power supply (AC to DC) ?
Diodes | Electronics Club
4 diodes is the minimum for a full wave rectifier. If you're satified with half wave, you can use only one diode in series with the load.
Jiggy-Ninja:
4 diodes is the minimum for a full wave rectifier. If you're satified with half wave, you can use only one diode in series with the load.
i see - okay, and that means half the voltage, right ? (compared to if one used the full wave rectifier?)
retronet_RIMBA1ZO:
WOW, look at those solid looking toggle switches !!
nothing like the dinky plastic ones we get nowadays !
They are all metal. Probably why this thing still plays games after 44 years-good components. I use it almost every day.
It has one huge capacitor in it, but that can be replaced very easily if that goes bad.
I just make sure to unplug it every time I'm done playing it. I never leave it plugged in while it's not being played. I have no idea what that would do, leaving a 44 year old electronic plugged in 24/7.
The TO220 case part in the bottom left corner is an LM7805 linear 5V regulator. The large grey cylinder above it will be a Vcc bypass/smoothing capacitor, and the green thing between them is also probably a Vcc bypass capacitor.