Lighting Ud

Hi broadgage no it was here in weymouth actually the health center which is at the end of my road. I'm in there again tomorow  so unless the appointment goes badly il try to look at the lighting again Thanks for the details of the control system used in London I didn't know that was a thing is it like a zellwegger ripple  control system? If memory serves it uses 1050 cycle ripple imposed on the 50 cycle mains wave 

The original cyclocontrol system involves changing the waveforms near the zero-crossings

In contrast Zellweger systems (still used in Oz) superimpose a continuous audio tone of a few volts RMS onto the mains - 1050Hz is one of a number of carrier frequencies used in different places.

Mike.

Wow just amazing what's been done in the past and even now my mate told me that there was a time in the early or mid 80s when every evening around 5 pm the transformer in his communication receiver would give a thump so eventually he foned the electricity board to ask them about it apparently the engineer said oh bloody hell sorry bout that it never happened again I now wonder if it was something like waveform changes or similar upsetting the transformer