Valve Rectifier

[sahib]

Last year I was asked to document an old  sub station for The Institution of Engineering and Technology. It turned out that the sub included a DC rectifier to power up the crane's drive motors. Yesterday I went to document another one which was in a mill house but was much smaller. Anyhow, these rectifiers are early mercury vapour types which are also known as Hewittic rectifiers after their inventor. So I thought it might be of interest.

It is 3 phase in, single 110V 50A DC out. We can probably up the output voltage but getting it in a 19" rack would be a bit of a challenge though.

 

[rodabod]

Scary, scary stuff.

http://en.wikipedia.org/wiki/Mercury_arc_valve

http://uk.youtube.com/watch?v=Rt-a8fxgtno

http://uk.youtube.com/watch?v=KGb-nUK41tc

 

[Larrchild]

Of course any glass object with a filament is gonna get a control grid from some wiseguy sooner or later.
Thyratrons and Ignitrons being a perfect example. Your dad's SCR.

http://en.wikipedia.org/wiki/Thyratron

http://en.wikipedia.org/wiki/Ignitron

 

[Walrus]

Ahhh...  memories.
Early '70's, Bromley College of Technology, ONC Electrical and Electronic Engineering course.
Doing experiments on mecury arc rectifiers was always best in the evenings, as we would open the cabinet and fill the room with the eerie purple glow...