Time Vector Generator
From Tardis Wiki, the free Doctor Who reference
A Time Vector Generator was a component of a TARDIS that made it dimensionally transcendental. Removal of the Time Vector Generator would collapse its interior, making it the same size on the inside as the outside. It resembled a long ebony wand and ess a powerful energy source.
The Second Doctor removed his TARDIS' Time Vector Generator to trap Atimkos. (MA: Invasion of the Cat-People)
The Doctor later removed the TVG when the fluid links exploded, filling the TARDIS with mercury fumes. The TVG was later used to boost Space Station W3's x-ray laser to defeat the Cybermen. (DW: The Wheel in Space)
Jared Khan attempted to steal the TVG from Bernice Summerfield on behalf of his masters, the Charrl. (NA: Birthright)
