Gives fully variable total spectrum floodlight output under remote control. Or it would but nothing now. Full of dust and fluff in the control area and a long term heat damaged , so presumably dramatically raised ohmage resistor. The bands are not discoloured , I think, reading 100 ohm , 5 percent and 1W size. Currently reading 47K, but scraping back the end thirds of the metal oxide spirals , the outer section thirds to each end are about 500 ohm each.
This resistor connects mains live to in-series opto-coupler, then small 3W mains transformer primary (supplying just a 7805 for the microcontroller) then neutral. The opto is 4 pin P620 , presumably Toshiba TLP620 , current going through back to back LED of 50mA rating with transistor receiver.
For the UK a 3W transformer would take about 12mA so 1.2V dropped across 100 ohm, does that seem about right ? presumably uprating to 2Watt, 100R. The LED side of the opto seems ok at 1V diode drop either way.
-- Diverse Devices, Southampton, England electronic hints and repair briefs , schematics/manuals list on