Commodore 64 Power Supply wall plug question

[Hannacek]

I got a Commodore 64 recently. The 3 prong wall plug from the power supply was falling off, so I went to the hardware store and got a replacement plug that you just strip the wires and screw them in. The green wire is ground which goes in the middle. Does it matter which side the other two wires go in? Is one supposed to be positive, and the other neutral, or does it not matter which of the two remaining wires goes into which side? I just guessed and screwed in the two remaining wires, and everything seems to be working fine. If anyone knows about Commodore, or other old computer power supplies, I would appreciate some help.

 

[carlsson]

I am not a qualified electrician, but as you have alternating current in the wall jack, the power will flow in a sine curve so it should not matter as long as you got the ground in the right place. This applies to all forms of electricity, not just Commodore.

 

For that matter, Commodore 64 power supplies in mainland Europe ususlly have a two pin, non grounded connector. I don't know if you live in the UK or US, perhaps the requirement of grounded equipment always have been stronger there.

[Hannacek]

The ground wire has green insulation, and is in the middle, so it would be difficult to screw that up. I live in the US. In the US at some point they made 2 plug electronics have one plug slightly bigger than the other plug, so you could only plug it in one way (see diagram below). So even though a toaster only has 2 plugs, one plug was bigger than the other so you could only plug it in one way. Older appliances have two small plugs, so they could be plugged in either way. I assume the Commodore is an older style appliance where you could plug it in either way (as long as the ground plug goes to ground), because I don't think they used the modern plugs by 1982.

 

[Osgeld]

it doesnt really matter cause it goes directly into a transformer and the only thing separating the two is a coil of wire

 

in reality its all because of safety, neutral is the low side of the line

 

ground is earth (Ideally the lowest potential possible) and its there just in case something comes loose, especially in a metal enclosure, that it will short out and trip the breaker instead of turning you into a torch when you touch your microwave(or you C64 doesnt explode in a ball of fire), neutral is the line with a low voltage potential, hot side is the wire that has a high voltage potential.

 

now if those are reversed and your working on something with disregard to total safety you may think you have disconnected the hot side, when in reality you disconnected the neutral side, this of course breaks the current flow, but what happens if you become the low potential side, while there is still a high potential in circuit.

 

at the very least a few choice words (cause you may be lower than the available potential, but not as low as ground), if your grounded you could become dead.

Edited September 23, 2014 by Osgeld

[RodLightning]

I recommend testing those old power bricks with a multi-meter. As also seen with the Atari 600/800 XL, they have potential to damage otherwise good working hardware. Those black commodore epoxy filled bricks have the same problems as the 'ingot' version of Atari's power supply. Many c64 hobbyists end up building or buying modern replacements. I got my first c64 this month and am looking into replacing the one that came with it.

[Rybags]

Neutral goes to ground as well. That's how the whole power grid works.

 

With 3 pin appliance the metal cover is typically wired to the ground pin, the purpose there is in event of a bad fault where eletrical flow is occurring to the case, it provides an easier path to ground - ie easier than otherwise flowing through the person holding the appliance.

 

Modern day it's usually "double insulated" - ie, the wires are insulated, the electrical parts and any metal coverings inside the machine are insulated from the outside world.