Is a voltage transformer with a max load of 30 VAC, OK for an Apple II ?

If makes a difference the Apple has one or two cards and one disk drive which I may increase to two in the future.

Is 30 VAC transformer load OK or do I need to move to 100 VAC or higher?

I have just learnt that I should be using 60VAC.
Case closed

I tried using a Franzus tranformer which says it will work for appliances from 50 watt to 1600 watt. The transformer works OK for hair dryers, irons, heaters etc

When I plug it in the computer does not switch on but only produces a humming noise, from the silver internal apple power supply,

Any suggestions?

you will run into problem.

Portable power adapters are designed for hair dryers, shavers etc when you are on holiday. They deliver an output that is adequate for a small motor or heater, but it is not sufficiently regulated (ie consistent AC wave form) to power a computer which has its own switched mode power supply. Computers require a proper 110V to 220V adapter -- they are more expensive but prices have fallen a lot in the the last five years. To identify a proper power supply, imagine something that is the size and weight of a house brick.

Thanks charlieman - would something like this work?
Is it the "toroidal" type which makes the difference

http://www.watt-power.co.uk/catalogue/100va-step-down-transformer-voltage-converter-p-790.html

100VA Step Down Transformer- USA to UK voltage converter. This is ideal to power a Nintendo Wii game from the USA in the UK. Maximum output 120vAC 0.83 Amps.
TYPE

Autotransformer
WINDING

Toroidal
INPUT

220/240V A.C. 50/60 Hz.
OUTPUT

110/120V A.C. 50/60 Hz.

That is probably powerful enough for an Apple II (with a few cards) on its own but the output is limiting. If you are likely to require a power adapter for use with other computers (or a monitor), something like this is better:
http://www.watt-power.co.uk/catalogue/300va-step-down-transformer-voltage-converter-p-792.html

You've got an original spec Apple II which is worth £600 (last selling price that I can recall) so paying an extra £20 on a better power adapter seems reasonable to protect your investment.

Thanks charlieman. While the 300watt power supply you suggested would have been a better choice, I already own a 100watt toroidal power supply that is working well with the Apple II

A dumb question - if I want to connect a small monitor (around 40 watts) in addition to my Apple II, is it OK to use the same 100watt transformer and connect two devices in parallel? (assuming the total wattage of the Apple+monitor do not exceed 100 watts. An ever dumber question but how do I convert one US socket on my transformer into two?

Its easy to convert one socket into two, or even six. Over here we have what is called a Power Strip, these are absolutely magical. Its just a plug on one end, with a short cord, and anywhere from 3 to six outlets arranged in a line, which you can then plug everything into.

Try turning on the monitor first, then power up the Apple. A CRT monitor uses the most power at power on.

Your voltage transformer will comfortably support an Apple II and a monitor (100W is adequate for a contemporary business PC and monitor, though not a max spec gaming PC).

Buy a standard power strip, cut off the mains plug and replace with a US spec mains plug. Correct wiring is important :-) Then you can use standard IEC power leads from your own country for the monitor and Apple II. Just make sure that you only plug them into the transformer/power strip.

Thanks for all the suggestions. What I need is a simple US 2 way adaptor which will allow me to connect 2 US devices into one US socket. Strangly I have been unable to find this adaptor on the web or in my local electrical store (Maplins). Maybe I am using the wrong search term, surely this must be a widely available widget?

Can someone point me to a site (preferably UK but I am happy to order from US or Europe if required) which sells a 2 way or multiway US style adaptor?

(P.S. the reason I want a simple US style 2/multi way adaptor and not a power strip is that I am 90% sure I will have no more than a small 8 inch color monitor which already has a US style plug + the Apple II, again with a US plug. I want to avoid the additional clutter and cabling of a power strip)

The receptacle side is called a NEMA 5-15R and the plug side is called NEMA 5-15P. That may help you with your search.