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Kerosene
December 10th, 2009, 10:05 PM
My VIC-20 finally arrived today, and although I thought it was a DIN powered model (which could use an AU Commodore 64 PSU), it's actually a 2 pin model.

How can I power this using 240v in Australia?
Is it as simple as getting an Australian 9v AC adaptor with the same 2 pins on the end? (I bet it's not!).

The red breakout is what it says on the 2 pin connector, just in case it's relevant...

http://i48.tinypic.com/1675zd5.jpg

As for my new VIC, it's in SUPERB condition, and looks like it may have spent the last 25 years in the box.

http://i49.tinypic.com/11kd008.jpg

carlsson
December 10th, 2009, 10:54 PM
Well, for most part if you get a two-prong ~220V PSU it will work the same. Internally there are voltage regulators and stuff to bring the voltages down and rectify them. The only thing that can be different is the frequency (phase?) of the 9VAC in the user port, if you would have any external hardware that is synchronized to 50 or 60 Hz.

On the other hand those two-prongs are a little hard to find, and so are general 9VAC transformers capable of delivering 20-30 VA. Thus it would not be a bad idea to invest in a step-down converter so you can run any 110V device in your household. There are plenty of inexpensive and supposedly safe converters on eBay if you look around a bit.

By the way, good point about getting an Australian power supply. Yet to this day, a lot of people have the misconception the two-prong 9VAC power supply is strictly an NTSC thing and all PAL VIC-20s came with DIN-style power to start with. That is absolutely wrong, there are VIC's of both generations and both video modes. The only way to detect an NTSC from a PAL model on the outside would be to read the sticker underneath the computer. Otherwise one has to open it up and read the chips if you have no means to power it on and check the display.

Kerosene
December 10th, 2009, 11:03 PM
The only external hardware I'll be using is a Commodore tape drive.

If I was to try and find a new (third party) AU adaptor, what specifications do I need to look for? 9V AC, 20-30 VA - is that all I need to know?

Anyone know the actual name of those 2 pin connectors?

I might just have to bight the bullet and get a step down converter. It's probably the safest thing to do. I don't wanna fry my VIC!

carlsson
December 10th, 2009, 11:07 PM
The original PAL PSU is marked 9VAC 27VA. After detailed measuring it has been found it doesn't draw that much power so theoretically you may be OK with 15-20 VA. To my knowledge, that particular connector has no known product name, but certainly it should've had one some 30 years ago.

Kerosene
December 10th, 2009, 11:19 PM
Now for a really stupid question - does it matter which way the 2 pin connector plugs in? It can go in either way.
I remember in the 80s that it didn't matter on most equipment.

Thanks for all your help Anders :)

Ole Juul
December 10th, 2009, 11:59 PM
Now for a really stupid question - does it matter which way the 2 pin connector plugs in? It can go in either way. . . .
For AC both connectors are the same. There is no +/- to worry about. For DC you have to have it the right way around. :)
I see the PS says 10VAC, that means 10 volts AC so either way is fine.

Kerosene
December 11th, 2009, 12:04 AM
I've just been looking at step down converters.
To run a 110v adaptor that outputs 30VA, do I really need a 3300+ watt step down converter? They start at around AUD $1200!

Somebody please tell me my maths is wrong!

Looks like the VIC is getting closer and closer to being a shelf queen.

tezza
December 11th, 2009, 12:19 AM
I've just been looking at step down converters.
To run a 110v adaptor that outputs 30VA, do I really need a 3300+ watt step down converter? They start at around AUD $1200!

Somebody please tell me my maths is wrong!

Looks like the VIC is getting closer and closer to being a shelf queen.

The maths MUST be wrong. I got a step down converter for my US-sourced IBM PC and it cost me about $30 (NZ!)

Tez

Kerosene
December 11th, 2009, 12:37 AM
The maths MUST be wrong.
Yep. Way wrong in fact. I was using VA instead of amps.

According to tortech.com.au (who have a good reputation for step downs in AU):

Do you know the Amps of your device? - is so you can calculate the watts required:
Calculated as = Amps x 110v (eg 5 Amps x 110 = 550 watts)

But I can't work out how to convert 30VA (the US VIC adaptor) to plain old amps.

???

Ole Juul
December 11th, 2009, 12:49 AM
VA means Volts times Amps. So 30VA would be 1 amp and 30 volts. If you are talking about 10 volts then 10 times what is 30? Easy ... 3 amps. Like carlsson said though, it won't take that much. There is a large margin of safety in the rating. He seems to know these machines so 2 amps or 20 watts is OK.

BTW you can call VA watts for all practical purposes. 30VA is 30 watts.

BTW2 the amps that a device draws is dependent on the voltage available. If you up the voltage the device will draw a higher amperage. Google ohms law. :)

carlsson
December 11th, 2009, 01:05 AM
It is also interesting to notice the 117V adapter says 10VAC while I'm absolutely sure my 220V adapter says 9VAC. If anything, it tells you about the voltage regulator inside the VIC.

I think my step-down converter is rated for 110V 50W or so, could be 100W too because I settled for a little beefier model to start with.

From what I understand, the difference between VA and W is that Watt says how much effect you get out of the power supply while VA says how much it "charges" from the power line. A rule of thumb says W = VA * 0.7 on a transformator.

Kerosene
December 11th, 2009, 01:13 AM
3 amps x 110v = 330 watts

So if the VIC doesn't actually draw the full 30VA, could I get away with a 300w step down converter?

I've never been good with volts, amps and ohms. It's on my study list :oops:

carlsson
December 11th, 2009, 01:48 AM
I think it is more like at 110V, the power supply (or computer actually) will draw up to 30 VA. Thus the step-down transformer should be rated for 110VAC 30W out. If the formula W = VA * 0.7 is correct, the step-down transformer may also be marked 110VAC 43VA ~= 50VA.

You can also look on the underside of your VIC-20. On the label it should say how many watt it consumes. It should be a figure around 15-25W if I recall correctly.

MikeS
December 11th, 2009, 05:07 AM
3 amps x 110v = 330 watts

So if the VIC doesn't actually draw the full 30VA, could I get away with a 300w step down converter?

I've never been good with volts, amps and ohms. It's on my study list :oops:As Ole says, for all practical purposes VA=W, so you need a converter rated at 30 Watts or more.

Kerosene
December 11th, 2009, 05:19 AM
There's some 300w step down converters on eBay AU for $50 delivered.
Here's the specs:
http://tinyurl.com/y9a9yhj

They seem pretty cheap. I think I'll buy one...

MikeS
December 11th, 2009, 05:26 AM
VA means Volts times Amps. So 30VA would be 1 amp and 30 volts. If you are talking about 10 volts then 10 times what is 30? Easy ... 3 amps. Like carlsson said though, it won't take that much. There is a large margin of safety in the rating. He seems to know these machines so 2 amps or 20 watts is OK.

BTW you can call VA watts for all practical purposes. 30VA is 30 watts.

BTW2 the amps that a device draws is dependent on the voltage available. If you up the voltage the device will draw a higher amperage. Google ohms law. :)
Your bottom line is correct; for practical purposes 30VA is 30W and that's at least what the 220>117 adapter should be rated at.

But I think you're adding to the confusion with your higher voltage=higher amperage; when you're talking about the currents in a transformer, as we are here, then the opposite is true: for a given wattage/VA rating, the higher the voltage, the *lower* the current (amperage).

VA=Volts x Amps; therefore A=VA/V
At 10V 30VA=3A (30/10)
At 110V 30VA=.27A (30/110)

And as a rule I would suggest going to a higher rating if anything, not lower; note the first word in "safety margin."

As Ole, Carlsson and I have said, 30W is all he needs, but if the OP wants to buy a 300W unit, that's fine.

Dwight Elvey
December 11th, 2009, 05:48 AM
Hi
It looks like it may be a switcher/ If so it may have
a jumper for 220v. Also, even if it is a transformer
model, it may have dual primary windings and
can be easily reconfigured for 220.
Do be careful to get the phasing correct.
Dwight

Kerosene
December 11th, 2009, 06:11 AM
Hi
It looks like it may be a switcher/ If so it may have
a jumper for 220v. Also, even if it is a transformer
model, it may have dual primary windings and
can be easily reconfigured for 220.
Do be careful to get the phasing correct.
Dwight

Huh?
Dual primary windings?
Phasing?
:shocked:

"Just when I thought I was out... they pull me back in."

I'm prepared to spend $50 on a 300w step down converter. I was hoping that would be the end of the story. I just want to fire it up and see if it works!
If anyone else wants to confuse me, now would be a good time to do it.

http://i45.tinypic.com/33kzu4x.jpg

carlsson
December 11th, 2009, 07:54 AM
It strikes me apart from the 117V/220V variants, there exists at least two different versions (looks) of the same transformer. I can't recall if they have the same part number. Usually this little beast runs quite hot and can break down due to heat, so if it would contain two separate windings of which only one is active at a time it would've been a waste of space from Commodore.

The 110V 300W step-down converter will be an excellent choice. It will allow you to power bigger PC compatibles and other stuff imported from the USA, if you ever would want to do that. Or of course you could get an extention block and have many smaller devices plugged into it.

Ole Juul
December 11th, 2009, 11:26 AM
But I think you're adding to the confusion with your higher voltage=higher amperage; when you're talking about the currents in a transformer, as we are here, then the opposite is true: for a given wattage/VA rating, the higher the voltage, the *lower* the current (amperage).
Sorry. I agree with perhaps adding to the confusion. I am however correct. I said that because I firmly believe that everyone must understand ohm's law and that is what I was illustrating. With that understanding, there would be no questions here. It's not that hard. :) E=IR, or as in this case I=E/R.

Anyway, the bottom line is that the OP needs to get a transformer for his computer which is rated at around 10 volts on the secondary and 220 volts on the primary. Since it sounds like 2 amps will do, he can probably find one laying around. I say "around" because the device obviously has internal rectification and regulation. Carlsson mentions 9V on another unit, so we know that is OK. Anything in the range of 8 to 11 should be safe to try and it is even possible that further afield is fine. Lot's of devices use that range and one wall wart is as good as another. Even if the power rating (anps or watts) is a bit low it might still work. If it gets too hot or burns out - try another one.

The more complicated solution is to get the 220 to 110 transformer and stick it in between. This is useful for other things too so I agree with the recommendation. They come in all rages and 200-300 is practical here, but I've seen them as low as 50 watts at about a $30 price tag and that would work for this purpose.

MikeS
December 11th, 2009, 05:58 PM
Huh?
Dual primary windings?
Phasing?
:shocked:

"Just when I thought I was out... they pull me back in."

I'm prepared to spend $50 on a 300w step down converter. I was hoping that would be the end of the story. I just want to fire it up and see if it works!
If anyone else wants to confuse me, now would be a good time to do it.

http://i45.tinypic.com/33kzu4x.jpg
Go for it! 300W will do a fine job; we're just trying to confuse ya ;-)

MikeS
December 11th, 2009, 06:12 PM
Sorry. I agree with perhaps adding to the confusion. I am however correct. I said that because I firmly believe that everyone must understand ohm's law and that is what I was illustrating. With that understanding, there would be no questions here. It's not that hard. :) E=IR, or as in this case I=E/R.

You're correct if you're talking about resistance, but my point was that the discussion was about power, not resistance; Ohm's law says P=IE, so in that context as the voltage goes up the current goes down, not up.

The OP thought that since 30VA meant 3 A at 10V then he needed a transformer to handle 3A at 117V (>300VA), so I thought it worth while to mention that when you're talking power as the voltage goes up the current goes *down*.

Kerosene
December 19th, 2009, 05:58 AM
Success!
Thanks for the help everyone. It's great to have a working VIC back in the house again! :)

http://i46.tinypic.com/2we01dt.jpg

carlsson
December 19th, 2009, 07:40 AM
And you get a colour picture too! It means you have quite a decent TV set, even if you operate it through composite video which is quite easier to handle than RF signal.