Fixing up a Norman 200c.
This is the later version of the time proven reliable Norman 200b. This 200c was part of a group of Norman strobe system bits. Inside the 200c battery compartment was a note saying blown fuse, needs repair. No schematic, but some idea of what might go wrong causing the fuse to fail. High on the list were the power FETS used to drive the HV converter transformers. Turns out this guess was correct. One of the four BUZ11A power fets was shorted Drain to Source causing the fuse to fail. The difficult part was extracting all four power fets for replacement.
The power configuration of the 200c is different than the 200b as likely has two sections of HV power conversion which is switched as needed to vary the power output of 50w/s or 100w/s or 200w/s. Two BUZ11A power fets are run together in parallel per HV power conversion section. This also means best to match the two BUZ11A power fets per section. BUZ11A power fets have been around for decades, easily available at low cost. Got a more than a few stuck them on the Tek 576 curve tracer matching up the sets needed.
Made up the power device mounting hardware and heatsink GOooo, put them in. 200c uses the power fet heatsink as part of their mechanical assembly and pcb support, sort of ok design.
Top of the pcb assembly.
Got the 200c back together.. remarkable it works after sitting waiting to be repaired all these decades.
No battery came with this 200c. Had to figure out the batter connections illustrated below. Notable is the battery pack's +12 volt goes direct to the case, battery return are the two spring terminals at the top. They are connected together to run the 200c. Next up, make a battery pack for the 200c.
200c is about half the weight of the 200b with the same light output.
This makes up a good Norman 200 system with more than one LH2 lamp head and reflectors and related accessories.
200w/s is not quite enough for view camera stuff, but the plans for these Norman 200w/s strobe units are in process.
Bernice
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