cuppajoe wrote:Assafl - Interesting idea, tho would require a good sense of electrical/electronics design and engineering as well as an intimate knowledge of the machine involved. Same idea as a computer power supply, take incoming voltage and break it down to other voltages going to various devices. Not too involved for a simple machine, but anything sophisticated would require knowing exactly where to tap in the 220V. Would make for a good experiment, just so long sacrificing it is not a problem if it bricks.

I currently use a 110/220 3,000W converter picked up for less than $100 on the bay. It's original purpose was to use with a Behmor roaster, as it passed clean 110V as well as being useful for up/down converting. Have used it with several 220V machines, mostly home levers. Made sure to get something rated for continuous load including heaters. A bit big, somewhat heavy(good sized transformers), but totally silent. One good thing is it's not tied to any one particular piece of equipment. All transformers and converters lose energy through inefficiency, including wall warts left plugged in. I turn the converter off when not in use.

Actually - it should be rather simple: if the heaters are controlled by a pressure sensor - just replace the original heater with 220v version and wire it to a separate mains cable (the trick here is to wire it through the main on/off switch.
If it is controlled by a Gicar/Giemme controller - it will usually have an SSR -solid state relay- which isolates the input and output (using an opto-isolator located inside the SSR). Again, separating the voltages is separating the two circuits after the on-off switch.

If you are using an auto-transformer - verify it is wired correctly. The 110v side should be wired so that the 110v is referenced to Neutral: so 0v-110v. Sometimes these Chinese sourced ones are wired so that the 110v is referenced to the hot (220v). So the 110v wires become 110v-220v. Theoretically - this isn't a problem since the effective voltage is still 110v; but there are two problems: 1. Insulation is rated for 110v to protective earth and it isn't explicit that 220v to ground reference is okay. 2. If the mains is protected from voltage surges using MOVs tied to earth - they are usually rated 10-20% above mains - so perhaps 135-150v for a 110v mains. They will short to ground, blow up, and may cause ground potential to lift (and destroy things like earth referenced electronics).