Mercury arc rectifier #4 pictures from a forum member:

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Tony S

© Honorary Lifetime Member
Sep 24, 2012
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Resting under the Major Oak.
This video clip shows one of Grendel ’s mercury arc rectifier’s in action. It also shows just how beautiful and how mesmerising they are in operation. As an apprentice I would spend far too much time watching them in operation, probably why my eyesight is so bad.

This bulb can also be switched to thyratron mode to convert DC to AC.

DC electric railways tried to make use of this for regenerative braking but there was a problem, the speed of change over. The only way around this was to have a rectifier and a thyratron side by side connected to the supply rail via a high speed switch.

To control the inverse operation needs control grids, clearly seen below the carbon electrode in this picture.

View attachment 9457

The following pictures are of a UK made Hewitic rectifier bulb just after being unpacked from its original packing case.

View attachment 9458

View attachment 9461

© Tony S

All pictures © Grendel

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