Zeiss Lamphouse and IDI Power Supply

[J_WISC]

Impulse buy. Appeared interesting. Didn’t cost much.

Here are photos of a Carl Zeiss lamphouse and an IDI Power Supply. It appears entirely cobbled together. Not sure it’s even pure Carl Zeiss as far as lamphouse is concerned.

First, can someone please suggest where to find more information about the lamphouse and proper use. I suspect it goes into the base of a microscope. There is a lens at the far left end. But there's another lens just left of the gray portion. And a third lens between the two. Nothing adjustable.

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Second, the power supply needs a new switch. What sort of information do I need from the part to search for a replacement. I opened the box, but i’m having trouble reading the letters and numbers on the part.

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THANKS!

[FredH]

The lamphouse looks very similar to the one shown on page 22-22 of Standard POL and WL POL Microscopes (https://archive.org/details/manual_Zeis ... ion_Manual).

How do you know the power supply needs a new switch? Is it just a switch or combined switch/potentiometer?

FredH

[J_WISC]

How do you know the power supply needs a new switch? Is it just a switch or combined switch/potentiometer?


The knob is difficult to turn and the light intensity isn't stable as the knob is turned. So I assume the component is worn. I don't know about electronics. It appears a combined switch/potentiometer. I thought it would be easy to Google a replacement part, but I might not know the correct terms. Also, it might be easier/cheaper to replace entire power supply. The combination of sketchy light and power supply cost $7.00. The light is nice, the power supply not so much. But I've seen several Zeiss microscopes for sale missing the light. I think I'll have a use for it.

Here's a photo of interior part:

IMG-2813.jpg (39.94 KiB) Viewed 855 times

Thank you for suggestions.

[blekenbleu]

It appears a combined switch/potentiometer.

Indeed, they are called potentiometer with SPST switch, for which variations include:

• mount and shaft dimensions

• resistance and taper.

Some will have manufacturer and part number stamped or printed on them,
but can be replaced based on measurements by caliper and Ohmmeter:

• resistance between outer two terminals rounded +/- 10%

• shaft diameter will probably be a little more than 6mm, often called 1/4 inch

The knob is difficult to turn and the light intensity isn't stable as the knob is turned. So I assume the component is worn.

Potentiometers can sometimes be saved using so-called fader lube (video): https://www.youtube.com/watch?v=8dR0Cb5RUS0

Resistance measurements want a multimeter, e.g. https://www.amazon.com/dp/B098QFS5CC
A multimeter can also confirm whether that switch is indeed defective.
A digital caliper is similarly useful for microscope fiddling: https://www.amazon.com/dp/B09M225ZP9

Set wiper to middle of rotation and measure between center terminal and one outer:

• if 50% of previous resistance measurement, then linear taper, else audio

In the U.S., potentiometers in small quantities can be purchased e.g. from Jameco https://www.jameco.com/c/Potentiometer.html