How to lower mains voltage using resistors

[gingertube]

One other idea I have seen BUT not tried myself, however the guy who did it claimed it worked "like a treat".

Put a 24V globe (or 2 x 12v in series etc) in series with the mains input. It doesn't relly matter if its in the active or neutral side. Choose globe wattage such that globe current is matched well to ioperating current.

Cheers,
Ian

[johnm]

After thinking about this I decided if something is worth doing it's worth doing right, so I've ordered a custom made transformer for this project to solve all the above problems.

Thanks for all your replies

- John

[Tweeker]

Hi John,

and then using a meter connect the probs to the 300V secondary, and CT to measure the secondary voltage?

If its full wave rectified, one can use a zener to CT to drop HT voltage. Doesnt fix the heaters, but here one could use resistance without performance issue.

[TubeHead Johnny]

I want to drop the level of mains voltage supplied to a pre-amp from our measured 247V 50Hz AC wall outlet, to 220V, which the pre-amp is spec'd for.

Why don't you just get a power conditioner with voltage regulation (AVR)? Using resistors to lower AC line voltage is not a good idea (believe me, I tried it). All that AC is going to be transfered to heat...enough to heat your house! I know Tripp Lite has a few inexpensive 120V models at PartsExpress, but I'm sure
they have a 220V model as well.

[johnm]

Thanks for your suggestions, but I've gone ahead with ordering a custom-wound mains transformer, so problems solved

Thanks,

- John