Olympus BH-2 voltage adjustment?

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Rudix
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Joined: Sat Jan 21, 2017 11:30 am
Location: South Africa

Olympus BH-2 voltage adjustment?

Post by Rudix »

Hi Everyone.

I wonder if someone can give advice. I have 3 Olympus BH-2 microscopes in different configurations in use and I love them. Only one problem, they are all 110V models and our local voltage is 230-245V. I am running them via a step-down transformer and it works but it is inconvenient, wastes space and energy (the transformers run slightly warm even when not under load).

I can see the the switch underneath the microscopes is labeled 100-115V, on the inside the switch is labeled something like 230-250V. Is there maybe just a different tapping on the transformer that can be used to change them to 230-245V?

Any advice would be appreciated!

Thanks!
Last edited by Rudix on Wed Jun 02, 2021 10:04 am, edited 1 time in total.
Rudi

Rudix
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Re: Olympus BH-2 voltage adjustment.

Post by Rudix »

I found a manual that states that different transformers are installed depending on the line voltage. It also states that the output of the transformer is 9.5VAC RMS so if I can find a transformer that fits I could convert the scopes to 230-240V.

The shape of the transformer seems non-standard so the only option might be to rewind the transformer but that might be more effort than just leaving things the way they are :shock:

The one positive thing about this whole exercise is that while going through all my bits and pieces today to see what transformers I have I realized I have enough parts to assemble another BH-2 complete with transmitted and epi light fittings. I serviced the gears and moving bits today so tomorrow I will assemble the scope, still need to decide on a selection of objectives and condenser, might make it a dedicated phase or pol scope.
Rudi

Pau
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Re: Olympus BH-2 voltage adjustment?

Post by Pau »

(I'm not sure to really understand the question)
I can see the the switch underneath the microscopes is labeled 100-115V, on the inside the switch is labeled something like 230-250V. Is there maybe just a different tapping on the transformer that can be used to change them to 230-245V?
I can't say for sure but it sounds like you have an international two voltage model, it if is a switch between both positions just changing it should change the voltage input. A picture could be useful to understand the situation.
A simple test would be to switch it to 230 position and plug it with your transformer at 110V, if it has really changed to 230V input light intensity will be much dimmer and likely will be safe to plug it at 230V
Pau

Rudix
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Location: South Africa

Re: Olympus BH-2 voltage adjustment?

Post by Rudix »

Pau wrote:
Wed Jun 02, 2021 10:52 am
(I'm not sure to really understand the question)
I can see the the switch underneath the microscopes is labeled 100-115V, on the inside the switch is labeled something like 230-250V. Is there maybe just a different tapping on the transformer that can be used to change them to 230-245V?
I can't say for sure but it sounds like you have an international two voltage model, it if is a switch between both positions just changing it should change the voltage input. A picture could be useful to understand the situation.
A simple test would be to switch it to 230 position and plug it with your transformer at 110V, if it has really changed to 230V input light intensity will be much dimmer and likely will be safe to plug it at 230V
Thanks for the reply!

I was hoping that is the case but the switch on the inside marked 230-240V is actually the same switch that is marked 100-115V on the outside (on the bottom cover)!

I suppose they just used the same switch (the 230-240V markings are actually stamped on the switch).

This reminds me of a mistake I once made, I have 2 CH40's, one is a 100-115V model and the other a 230-250V model. Well, I suppose it was bound to happen, after a reshuffle on the bench the 100-115V model got plugged into 230V. There was a loud bang and a flash of light followed by that horrible smell.....

Great was my relief that the only damage was a blown fuse and a lamp that exploded, had her up and running in no time.
Rudi

carlh6902
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Re: Olympus BH-2 voltage adjustment?

Post by carlh6902 »

There is a 100/115V switch on the bh2, to select for operation between North America (115v) and Japan (100v). None are selectable between 120 and 240. Don't even think about trying that!

https://drive.google.com/file/d/16GJRjS ... p=drivesdk

Carl

Rudix
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Location: South Africa

Re: Olympus BH-2 voltage adjustment?

Post by Rudix »

carlh6902 wrote:
Wed Jun 02, 2021 7:48 pm
There is a 100/115V switch on the bh2, to select for operation between North America (115v) and Japan (100v). None are selectable between 120 and 240. Don't even think about trying that!

https://drive.google.com/file/d/16GJRjS ... p=drivesdk

Carl
Thanks, yes, I am aware of the normal switch range, there are also models that can be switched between 230-240V as well. I was hoping the difference is simply a different tap on the transformer like it lots of older equipment (including my CX41) but no such luck!
Rudi

Macro_Cosmos
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Re: Olympus BH-2 voltage adjustment?

Post by Macro_Cosmos »

I would just power the lamphouse directly with a variable power supply. I've learned to not mess with power circuits, the hard way.

Rudix
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Re: Olympus BH-2 voltage adjustment?

Post by Rudix »

Macro_Cosmos wrote:
Thu Jun 03, 2021 2:50 am
I would just power the lamphouse directly with a variable power supply. I've learned to not mess with power circuits, the hard way.
I did consider that and yes, it is an option but it would still result in an external device so not really better than the step-down transformer I am using at the moment.

I have no problem working on the power supply, I have designed and build far more complicated electronics than this including RF amplifiers that use lethal (up to 8000V) voltages.

I have found a transformer that will fit and of the right voltage and current capacity, I will install it but I could only find one, would have liked 4 to get everything converted.

My "build from spares" BH-2 produced it's first images today and it is perfect. I have configured it with normal and epi light sources and polarizers, along with 2 x quick change nose pieces it is now a very versatile microscope and will also be the receiver of the new transformer. I feels like it is a "free" microscope so I am happy with the result of all this playing around with bits and pieces.
Rudi

carlh6902
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Re: Olympus BH-2 voltage adjustment?

Post by carlh6902 »

Just to clarify, there were no imt2, bht, bhtp, bhtu, bhs, bhsp, or bhsu scopes made to accommodate 120 and 240v. Later scopes perhaps. But not bh2.

Carl

wowjl
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Re: Olympus BH-2 voltage adjustment?

Post by wowjl »

Rudix wrote:
Thu Jun 03, 2021 8:32 am

I have no problem working on the power supply, I have designed and build far more complicated electronics than this including RF amplifiers that use lethal (up to 8000V) voltages.
I take the liberty of interrupting.

https://www.microbehunter.com/microscop ... 25&t=15710

The green light version is obviously a later improved model and I'm just wondering what the purpose of the circuit complication is.

Macro_Cosmos
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Re: Olympus BH-2 voltage adjustment?

Post by Macro_Cosmos »

wowjl wrote:
Thu Jun 23, 2022 12:29 am
Rudix wrote:
Thu Jun 03, 2021 8:32 am

I have no problem working on the power supply, I have designed and build far more complicated electronics than this including RF amplifiers that use lethal (up to 8000V) voltages.
I take the liberty of interrupting.

https://www.microbehunter.com/microscop ... 25&t=15710

The green light version is obviously a later improved model and I'm just wondering what the purpose of the circuit complication is.
Keep in mind that I know nothing about finite microscopes, later does not necessarily mean better. I have handled some BH2s at an older workplace and they feel better than the BX40 I started the hobby with...
Looking at the diagram, it seems like the "red" LED version offers a voltage switch. Was it a case of 100/120 or the preferred 100/120/230/245 kind? I have a destroyed micromanipulator controller, had it set at 230 but my mains voltage was closer to 245... :cry: It went up in flames.

Be aware of repairs too, there is nothing stopping a previous user from swapping a green LED with a red one and vice versa... You learn it the hard way with fluorescence cubes.

I would honestly just power the lamphouse with an external power supply. Olympus/Nikon vintage models are $30 a pop. Look up "Olympus power supply". Make an adaptor cord, the tungsten halogen lamp has a couple of unpolarised pins.

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