Our buddy Phill composed, in an unusually non-berating way today thusly :

"Large electros kill spikes just like sledgehammers kill flies. "

And they got better aim. As long as you have full wave rectification, and the rectifiers can handle alot of peak current, they are quite effective. However they are not effective so much against having simple overvoltage applied.

You are not in the US, if the power there is like the UK or whatever it is different. While you have 240 coming in referenced to neutral, in the US it is half that. The line is balanced with two 120 volt legs out of phase. Almost all smaller appliiances run from one leg to neutral. If the neutral loses continuity it can apply as much as double the effective, peak to peak, RMS and whatever other way you want to measure it - voltage to your appliance.

This cannot happen in the good countries but I am not here to bitch. At the moment...

At any rate, I have seen a bunch of equipment saved by these MOVs over the years and in fact at one time I did install them as an option on repair jobs. When I worked where they sold service contracts, I should have installed them as a matter of standard operating procedure.

Of course this does not necessarily apply in other countries.

I have also noticed a few tings that actually switch themself. What most of them do is to simply rectify without doubling and then kick it up with a chopper circuit, the usual boost thing. When the incoming is well above the 160 rectified the booster simply shuts down and passes the juice.

A long time ago I worked on a bunch of little TVs for a limo service that actually ran on 24 volts but had an upconvertor for use on 12 volts. The upside to these little Sonys (who else ?) was that they could be simply connected into 24 volt systems (tractor trailers/lorries) with zero modifications.. You could fuse it a little lower but that wasn't all that bad.

I think as soon as Edison's body was cold they should have made it 240, yes center tapped like it is, but made all the outlets and appliances 240 all the time. they also should have changed the frequency to 400 Hz. (CPS LOL) Or better yet, maybe 360 or something to make it easier to make electric clocks. Synchronous motors would be a little more complex but think of all the speeds you could have.

Enough, I am not drunk enough to write more right now... lol.