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Need help for 220 V to 120 V PS conversion

Just hook it up to were your dryer/stove oven hooks up at run taps off that? I don't know if the over seas set up will take two hot 120v wires one neutral and one ground? For a total of 4 wires maybe it has three two hots and one netural.

On 2nd thought maybe that won't work I don't know! But if you do try be careful 220 hurts a bit, and makes bigger boom then 120 ;-)
 
tezza said:
For my donated American IBM-PC (115v) I bought an inexpensive step-down transformer so I could run it off the 240v mains.

Is there such a thing as a step-up transformer which will boost 115v to 240v? If so, the simplist thing might be to just leave things as they are and buy one of those?
Click to expand...

You can take any step-down transformer and run it backwards as a step-up transformer. I used to power the final off of my rig using a reversed "pole pig" as the plate transformer. For that matter, you might be able to feed only one side of the main power transformer and use it to develop 240v (with a corresponding loss in power rating).

But that's not the issue here. It's 60Hz vs. 50Hz.

The motors on an ac-powered 8" drive are synchronous with the power line frequency. Instead of resulting in a spindle speed of 360 RPM, you'll get 60/50 of that, or 432 RPM.

You could machine down the (crowned) drive pulley or substitute a timing pulley that would result in the right speed.

Or you can simply swap the drives out.
 
I've actually got another Altos (115 V version) that I can't get to work. I'm thinking I could switch the drives from that one to the Aussie one, but I'd really rather get the 115 V one working, as it's a multi-user machine.
I have all the schematics for the Altos - my problem is that I can't read the damn things well enough to figure out where the problem might be.

Are there any volunteers out there, who can read a schematic and point me in the right direction?
(It'd definitly be worth a few pints, on me).
 
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Mains freq. conversion

Mains freq. conversion

If you google "50 60 hz voltage converters", you'll see a wide range of stuff that converts 60 Hz into 50 Hz & vice versa. The new stuff tends to be pricey, but sometimes you can dig something up as surplus.
Unless you're running something that has an AC motor (like the 8" drives mentioned by Chuck(G)) , or something that derives timing from mains (like some older alarm clocks), it doesn't really matter if you run it via a simple transformer.
patscc
 
Another way is to get hold of a British or European power inverter - these are not expensive here but the postage might set you back a few $$. Preferably British as these should supply 240v rather than 220v. This will give you the desired 50Hz supply.

You'll need a beefy 12v power supply to feed it from though, but this can be built or sourced locally.







BG
 
My sincere thanks go to Chuck(G) and patscc, who both replied to this post.

These two replied to my request for help, and walked me through repairing my Altos 8200, via email.

They are brilliant !
They read the schematics (which I couldn't) and they provided great, clear instructions to troubleshoot the problem, and then what to do to fix it.

If these two were brain surgeons, you could do brain surgery on someone via email !

The Altos was saved from the scrap heap or being parted out, because of Chuck(G) and patscc.

Many thanks guys.

Lorne.
 
Our pleasure, Lorne!

Now, who's got a couple of 8" drives to sell Lorne--or who wants to swap some 120v 60Hz drives for some 220v 50Hz units?

That would get him on his way toward getting both systems working.

Thanks!
 
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