Wellington turned off the last mercury arc rectifiers in its electric commuter rail about 2010.
Plenty of heritage tramways and historic railways still use them. Polytechs keep all kinds of long obsolete equipment running for training purposes too - one, there’s still a need for people to operate/maintain it, and two, older gear can sometimes be good as learning tools due to simplicity. That doesn’t really apply to diodes vs mercury arc though…
They were the only practical option to get DC from AC until maybe the 60s, and they’re pretty bulletproof. They’re usually replaced because of upgrades, not failure/obsolescence.
Am I right in thinking the bottom right picture is of Cherenkov radiation, cause it definitely looks like it?
The eerily blue glow of photons and electrons moving faster than light through water, it’s fascinating stuff!
https://en.m.wikipedia.org/wiki/Mercury-arc_valve
Wow.
Amazing how we’re still using such old technology in some places when we have semiconductors.
Wellington turned off the last mercury arc rectifiers in its electric commuter rail about 2010.
Plenty of heritage tramways and historic railways still use them. Polytechs keep all kinds of long obsolete equipment running for training purposes too - one, there’s still a need for people to operate/maintain it, and two, older gear can sometimes be good as learning tools due to simplicity. That doesn’t really apply to diodes vs mercury arc though…
They were the only practical option to get DC from AC until maybe the 60s, and they’re pretty bulletproof. They’re usually replaced because of upgrades, not failure/obsolescence.
It looks like a mercury vapor rectifier to me.
I’ve just seen the link @mustardman sent, and I had no idea a device like that existed. No idea how it works, but it looks interesting AF