Traction electronics have been around for longer than you might think. When English Electric’s demonstrator locomotive DP2 rocked up at Finsbury Park depot in the summer of 1963, fresh from an overhaul at Vulcan Foundry, it incorporated a new piece of electronic wizardry. This was an anonymous grey box which replaced the previous electro-mechanical torque regulator.
In a diesel-electric locomotive, the torque regulator matches the load on the generator to the power output demanded from the engine by the driver. In the Class 55 Deltics I was working on, the torque regulator was an hydraulically-driven rotating arm with a roller on the end. As the arm rotated it closed or opened a ring of electrical contacts which controlled the excitation of the generator’s field.
With this design, if you suspected a torque regulator problem, you could whip off the cover and have a look inside. Wiping up any leaks from the hydraulics was always a good start.
On DP2, all this functionality was provided by the anonymous grey box, which had the gnomic designation KV10. When it went wrong, and it did, all you could do was phone up Preston and the boffins would come and fit a new one.
TEMPERAMENTAL
Jumping forward a few decad…
