ECN Forum Forums General Topics of the Trade Non-US Electrical Systems & Trades Saline Solution Control

Apparently in some regions liquid resistors for motor starting or speed control are common. www.deanhubert.pwp.blueyonder.co.uk/ossettindustrial/liquidstartersnew.html
Sodium carbonate in water is one regularly used solution for this duty.

This thread reminds me of a story my Dad told me many years ago. Employed as a maintenance fitter in the hospital service, around 1949/1950, he helped the electrician to build some lighting dimmers for amateur theatricals.
The dimmers were based on vertically mounted salt glaze clay drain pipes, filled with brine. A rope and pulley system raised and lowered electrodes. It apparently worked, without harming anyone either electrically, or with boiling brine !
I don't doubt the accuracy of the story as I recall it, nor the ingenuity of the people involved, but I've sometimes wondered if it was a unique and original idea, or as now seems likely a clone of a commercial system.

Just as well the Health & Safety Gestapo (Excuse me, I mean Executive ) weren't around in those days, or some of these innovative methods might never have been used.

I've never come across a brine or caustic-soda lamp dimmer. In my time as lights/sound man for amateur theatre the oldest technology I ever came across was the big linear and rotary rheostat dimmers. Mind you, some of those could be a little scary, and I remember how hot the little control booth got at the end of an act set at night!