The CV686 is a voltage stabiliser. The prototypes were the 0C3 and VR105/30.
Internally pins 3 and 7 are linked. This shorting link is designed to protect the connected equipment from overload, as when the stabiliser is removed the supplied circuit is disconnected.
The KB/RC identifies this valve as being made to specification K1001 or K1006, the B denotes qualification by a UK authority and the RC identifies the maker as Ferranti, Chadderton, Oldham.
The reverse carries the Type designations 0C3 and VR105 thus proving a direct equivalence to the CV686.
Construction of this gas filled stabiliser follows the normal pattern of closed cylinder with the second electrode as a central vertical rod.
References: Data-sheet & 1040. Type CV686 was first introduced in 1939. See also1939 adverts.
