Alternative 2 prong PSU

[eslapion]

ah so now you will change your answer again ......
now its a smaller trace and it gets smaller and what ever is next
so lets see the new size of .050 , I show max current 2.73A still better than the 1.5A fuse
and it narrows to what?

Go argue with the maker of the Arfon Micro expander.

Did you take a close look at the circuit board of a VIC-20 with PET style keyboard to say that?

Take a caliper and check it for yourself...



As for your "max current"; what temperature rise is expected? what thickness of copper are we talking about here? Is that peak or continuous?

BTW, that 1.5A fuse is slow blow so even the spikes of 5A you should expect with an old VIC-20 will not blow it.

Now... let me recap... the spacing from tab to tab is 0.156", the width of the tabs is approx. 0.1" and the trace between the 9Vac tab and the connector is 50mils or 0.050". Checked with a Mastercraft digital caliper bought at Canadian Tire.

Go argue with the maker of the Arfon Micro expander.

Commodore made the VIC-1020 expander which was similar in many aspects and they didn't power the VIC that way.

It's a bad idea today as much as it was 35 years ago...

[ken]

mrr19121970 asked if it could be done
and I did it to see ....and yes it can be done
I do do not care if you like it or not

all I did was try it ...and if you go look that was way more than you did
why not show a better way , oh wait , you only want to point out flaws and not help

[eslapion]

mrr19121970 asked if it could be done
and I did it to see ....and yes it can be done
I do do not care if you like it or not

all I did was try it ...and if you go look that was way more than you did
why not show a better way , oh wait , you only want to point out flaws and not help

Haa... I am familiar with this kind of discourse... If you can't suggest better then shut up...

Here's my answer:
If someone presents me with the plan of a time travelling machine and after carefully studying it I come up to the conclusion that this will not do what is claimed, do you think it's possible for me (or anyone else for that matter) to come up with a better suggestion ?

This is absolutely not a matter of me liking it or not and you using this type of language clearly shows an unscientific/irrational way of communicating. It's a matter of me taking the time to explain to you exactly what it will do to the best of my abilities and YOU not liking what you read.

The better way IMHO, is to do the same thing as on the VIC-1020; plug the 9Vac to the proper power connector. I'm sure you can find tons of images on the Internet. That's what Commodore engineers did and I think it's the right solution.

[mrr19121970]

Well the idea behind my suggestion was to help a guy out in the USA who bought a 2 prong PAL model with no PSU. Infact he took my least favoured suggestion and desoldered the 2 (split/wider) prong connector and replaced it with the narrower style.

[eslapion]

Well the idea behind my suggestion was to help a guy out in the USA who bought a 2 prong PAL model with no PSU. Infact he took my least favoured suggestion and desoldered the 2 (split/wider) prong connector and replaced it with the narrower style.

PAL VIC-20s with 2 prong PSU have been equipped with a power connector with a plastic tab that prevents incidents which were frequent in north america where people used electric razor's power cords and plugged 120Vac directly into the computer.

The downside is that finding the right type of connector or making one for these VIC-20s is quite cumbersome.

This was one of the main reasons why VIC-20s made after 1982 and C64 are equipped with a round power connector. This can't occur with these machines.

I had a PAL 2-prong VIC-20 in the past (was unfortunately destroyed when my stuff was sent to a warehouse when I was hospitalised in 2014) and I made a custom connector for it using a pair of alligator clips and thermal glue.

This gentleman's replacement connector isn't a bad job at all but this now makes this machine vulnerable to the same fate all other NTSC 2-prong VIC-20s can suffer.

The Amibay thread does not indicate what your other suggestions were. Could you please tell us about them?

Also, the pictures in there clearly show the width of the traces on the power connector are much wider than those making the connection between the 9Vac wiring connector and the edge connector tabs.

[mrr19121970]

Here are my other thoughts

My favourite is still the test hook/probes soldered to a barrel connector dangling out of the cartridge case. The test probes would then be attached to the back of the power inlet and still use the ferrite bead and on/off switch as before. This way is non invasive & reversible too.

[eslapion]

Here are my other thoughts

My favourite is still the test hook/probes soldered to a barrel connector dangling out of the cartridge case. The test probes would then be attached to the back of the power inlet and still use the ferrite bead and on/off switch as before. This way is non invasive & reversible too.

Unlike the north american connector, the european connector has exposed contacts so as long as the test probes can take the current it seems like a good "reversible" solution.

Changing the power connector to a north american type is electrically adequate too, just not reversible.

Both of the above are certainly much better solutions than powering through the user port. This is not a matter of me liking or not liking a solution; this is a matter of physics - passing that much current in such small traces will cause an excessive temperature rise.

[Boray]

You can use two crocodile clamps to connect to the european two prongs. Works perfectly. I even have a picture of it in my camera that I will post in a couple of days.

[e5frog]

I already saw them in another thread, but here we are still waiting.

Just happened to stumble upon this thread as it was linked to in another discussion.

Doesn't seem like a good idea to power from that end, mostly because of the thin traces between edge connector and cable and maybe the contact area between female edge connector and the edge connector.

But if they're 50 mil wide with 1oz copper they'll be able to handle almost 3A (2.85A) continuously with 10 degrees raise in temperature.
http://www.4pcb.com/trace-width-calculator.html

I don't think I would do it that way but it might work fine, for a while at least. A pair of wires could be added to fix that detail.