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Convert 220v/50Hz illuminator to 120v/60 Hz. Safe to plug in?

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mcfudge:
Last week Amazon shipped me a "great deal" of an item (1/3 price) but with the wrong specs -- European power instead of North American.  Is it safe to plug in to 60 Hz, or can this be converted to 120V 60Hz?  I've done a lot of reading but haven't found a clear enough answer.

It's an AmScope microscope illuminator (fiber optic dual gooseneck light) model HL150-AY.  Instead I think it should read HL150-AY-220V.  They make both models.  It has a European plug, is marked AC-220V 50Hz on the back, and the documentation indicates it requires 220V +/- 22V 50Hz +/- 1Hz.  I have a step up transformer to get 220V but the output is still 60 Hz.  I'm tempted to plug it in but for $200 I don't want to fry it.

GoHz has a 500 VA frequency converter for $1,100 USD, nice to have perhaps but buying that for this item defeats the "great deal".  I'll post some pics and hopefully I can get some advice including modifying the single mainboard as needed.  Thanks in advance.

Myles

Zero999:
60Hz shouldn't be a problem. It's operating a 60Hz device at 50Hz which would be more of an issue.

Gyro:
I'm not sure what lamp it uses, I'm assuming Halogen.

The PSU is a non-isolated forward converter, not a problem as long as all wiring is inside the grounded enclosure. Unfortunately I can't see any evidence of links or jumpers on the board to convert it to 120V, they must use a different PCB.


P.S. That's a really lousy choice of a mains input connector, I'm not even sure it's legal!  The mating socket has very little clearance between the contacts and the outside world (or the metal shell). Why on earth didn't they use an IEC? ::)

Yansi:

--- Quote from: Gyro on February 17, 2019, 11:30:51 am ---P.S. That's a really lousy choice of a mains input connector, I'm not even sure it's legal!  The mating socket has very little clearance between the contacts and the outside world (or the metal shell). Why on earth didn't they use an IEC? ::)

--- End quote ---

It most then likely isn't,  but it is convenient that (school) laboratory equipment manufacturers are complete jerks that like to sell overpriced crap - I have seen more examples of this "obfuscatory" designs in school lab eq., to force customers buy only from them - the specific manufacturer, that makes the purest BS of all.

The PSU is of one of the worst junks I have seen. Not even sure why they have opted for this overly complex nonsense, they could have just used a 230V halogen bulb on a triac dimmer. Much cheaper, same result.

I do not see anything complicated to convert it to 120V.  Just rewire the full bridge rectifier into a half wave doubler circuit. (You will also need to replace the small mains transformer  though).

Richard Crowley:
Is there no nameplate on the frame of the power supply module?
That looks very much like a modern switch-mode power supply (SMPS).
Virtually all SMPS are "universal voltage" and are designed to operate properly from 100V to 240V AC
Or in some cases, there is a switch or jumper, etc to switch between 100-120V and 220-240V

The power mains FREQUENCY is of no importance at all.
Because the SMPS is converting the power to very high frequency AC, and then to DC, so it makes no difference what is coming in.

Traditional "linear" power supplies used a "heavy iron" transformer that operated directly at the mains frequency. Many products that were designed for use at 60Hz will overheat at 50Hz because of the marginal (cost-cutting). But SMPS do not suffer from this phenomenon.

I agree that is a particularly poor choice for the mains input connector.  If you don't modify the unit to use an IEC connector, I would certainly avoid handling it especially when plugged into the mains outlet. Connect it and tighten the ring and never remove it when plugged in.  I would remove it and substitute a proper IEC connector.

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