I served in this unit from 1980-82, it supplied power to 7 Signal Regt and 16 signal regt. Its full title was,HQ 1 BR Corps Lighting Troop Royal Enginners.
We had numerous Meadows 27.5kva generators and a few 40kva Hawker Sidley sets.
The Troop was based in North Camp 7 Signal Regiment Waldfrieden Camp.
I believe the unit started back in WW2 as one of several seachlight units.