Re (3): Voltage halver.

RL and all,

In article <3hot0jdfedfel1pm82vnqbn04u2bq29q37@4ax.com>, legg <legg@nospam.magma.ca> wrote:

I also note that in the zeiss opmi_1 manual, a 12V 100W halogen lamp
is specified - and a self-resetting thermal limiter is built into
the lamp holder.

You have an original paper manual?

OPMI 1 is a family of microscopes rather than a specific model;
correct?

A search in eBay, for example, finds many variants. Appears that
components were assembled according to requirements of a customer.

A search found this URL.
http://www.frankshospitalworkshop.com/equipment/documents/microscopes/user_manuals/Zeiss%20OPMI%201%20FC%20Surgical%20Microscope%20User%20Manual.pdf

The 2nd supplementary page after page 31 lists these bulbs.

Endure Number                 Spare Bulbs

90-1200  Zeiss  6V  30W Bt58Z       390158
90-1201  Zeiss  6V  50W Bt86Z       390186
90-1202  Zeiss 12V 100W HLX #64626  380075 1020
90-1203  EFR    Housing #900
90-1204  Zeiss 15V 150W EFR         310198
90-1205  Zeiss 12V 100W HLX #64627  380079 9040
90-1206  Zeiss Superlux  40
90-1207  Zeiss Superlux 175
90-1208  Zeiss Superlux 300 with Cartridge
90-1209  Zeiss Superlux 300 Bulb Only - No Housing or Meter

90-1302  ELS 150 21V 150W EKE
90-1400  ELS 250 24V 250W ELC
90-1403  ELS  24 60V  24W Metal Halide
90-1402  ILO         300W with Cartridge

EFR, ELS and ILO are bulb manufacturers?

After my original enquiry, also found a page for a replacement LED
illuminator. 700+ $US.  Beyond my budget at present.

Also found some old bulbs in boxes labeled 390153.  They have the
unusual (Zeiss?) triangular base and the filament is parallel to the
bulb axis.  The 39015 has the filament crosswise to the bulb axis.

Also found an inexpensive motor controller which adjusts light
intensity nicely. The adjustable power brick can be set to deliver 6
V.  The controller connected beyond that adjusts intensity.

In case a 90-1202 Zeiss 12V as listed above turns up, my power supply
should suffice for that also.

Thanks to all for the replies,                ... P.