In a previous Blog- Wednesday 26th July 2017 titled 'Thoughts on the First VALOY enlarger' I wrote at some length on the need for electrical safety which seemed lacking in the early days.
I have now been able to disect a late Focomat lamphouse in detail. This is one of the last Colour models which had signs of the modern age with a magnification indicator lit from within by a gas filled bulb (of a type that has not been seen recently). I think a 'fridge LED will fit as long as the final figures are lit in red by a gel filter, but the gas bulb is still live.In fact there is little need for this in the intended Black and White use that I plan.
The lamphouse is of a degree of sophistication not seen in past Leitz heads. It can be taken apart by a series of fine screw threads and the three spring fittings that locate the bulb have captive springs and are a perfect and logical development of the past designs that had faults in the service department. The wiring is three core with a lead to an earth screw fitting within the lampholder. All the wiring seems to show a continuity of earth with a separate earth wire to the screw on the column. They have really tried on this one.