MicrobeHunter.com Microscopy Forum

Does anyone know for a fact what power supply originally came with the M5 in this configuration? By the way, I know they offered a ring that goes on the objective for the lights, but I don't have that piece. I have a MTr 22 0-8v that the switch isn't working, but I'd like to know what power supply actually came with this model.

The M5 was made for decades. They msy have offered it with a few similarly specced power supplies over that period. I've certainly seen plenty of variations from the wild/leitz family.

Scarodactyl wrote: ↑

Sun Feb 18, 2024 10:53 pm

The M5 was made for decades. They msy have offered it with a few similarly specced power supplies over that period. I've certainly seen plenty of variations from the wild/leitz family.

Thanks, I'm aware of that. I just thought someone might know the era that it actually came with. The one I have isn't working. I fired it up once and it never worked after that. I assume the push button switch is history. I tried cleaning the switch with Deoxit and cycled it dozens of times, with no luck. Guess I'll be looking for another.

-JW:

You probably know this, but the area of exposed autotransformer coils and the (usually) carbon brush that sweeps through it are often oxidized in old units. That might also require attention.

PeteM wrote: ↑

Mon Feb 19, 2024 6:05 pm

You probably know this, but the area of exposed autotransformer coils and the (usually) carbon brush that sweeps through it are often oxidized in old units. That might also require attention.

No, I did not. Unfortunately, I am not electronic savvy. I will give that a try but it won't even power up. I was going to try and jump the switch to see if it is bad but can't get to the bottom connector with a wire.

I took a chance and jumped the switch and a lamp came on that I had attached to the power supply. So, it looks like the switch is history.

It sure would be sweet if I could get an aftermarket replacement switch with a power on light indicator.

You should be able to find something as that was a typical panel thickness and material back then, and Wild allowed a generous amount of room around the switch. I might want to measure the transformer's power up, inrush current to help choose a switch that can handle it.

Finding something that would work would be nice. Like I said, I'm not too savvy on electronics.

Thanks for the picture. I would say that is a 5A/250V illuminated switch with a 60V/1.2W bulb. I believe you have a Wild MTR 22 transformer. I have an MTR 28, which has a meter instead of the lamp, that I could look at and measure. It came with a microscope made around 1980.

jfiresto wrote: ↑

Mon Feb 19, 2024 10:31 pm

Thanks for the picture. I would say that is a 5A/250V illuminated switch with a 60V/1.2W bulb. I believe you have a Wild MTR 22 transformer. I have an MTR 28, which has a meter instead of the lamp, that I could look at and measure. It came with a microscope made around 1980.

Thanks for the information, it's appreciated. I seriously doubt that I will find a replacement UNIMAX 01-221. I did see a UNIMAX 01-261 on eBay that physically looks the same, but it's a different model number. I haven't a clue if it would work.

Try this as a search for suitable replacement switches:

https://uk.rs-online.com/web/c/?searchT ... ton+switch

The left side-bar on that page will let you refine the search

MichaelG.

That 01-261 looks promising, and I might take the chance if it cheap and you are trying to avoid a little metal (re)working.

It is not like you have to buy a bunch of an old part. On that note, if anyone needs a replacement fuseholder and/or cap for a Schott KL 1500 electronic halogen light source, in grey not black, I have 76 and 70 of them, respectively. They were cheap.

I should have mentioned that I expect both switches take a replaceable bulb of up to 60V and 1.2W, that you would choose to match the transformer's output voltage and the required brightness and operating life. It has been a few decades since I worked with such switches.

jfiresto,

jfiresto wrote: ↑

Tue Feb 20, 2024 10:06 am

That 01-261 looks promising, and I might take the chance if it cheap and you are trying to avoid a little metal (re)working.

I paid $5 for it so it's worth trying. I have photos of the 01-261 from all sides and it is an exact match physically photo-wise, including the rear connection markings. I'm not sure what the difference is between the original broken one and this one. The eBay one is on the left, and the original is on the right in the photo below.

-JW:

I wish you luck that the differences will be inconsequential, for example, having a different lens color rather than being momentary vs. alternate action.