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I've two Vibro Graver electric engravers (120V 60Hz) with me. I gave one to a friend who recently moved to another country. He got a step down converter from 220V to 110V but then he noticed the frequency used there is 50Hz.

What would the effects of using the device on a 110V 50Hz supply when the device is meant to be used on 120V 60Hz supply. Does the 10Hz difference cause any damage?

Edit: The voltage is stepped down from 220V 50Hz to 110V 50Hz Img 1

IMG 2

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  • \$\begingroup\$ Likely will go unnoticed...And 120V to 110V stepdown? I doubt it is needed as well. \$\endgroup\$ – Eugene Sh. Oct 26 '17 at 20:39
  • \$\begingroup\$ So, its safe to go ahead? I'm slightly confused because a person told me yesterday that sometimes inductive devices don't like frequency changes much. Is it true? \$\endgroup\$ – The_Vintage_Collector Oct 26 '17 at 20:41
  • \$\begingroup\$ That's true. The question is how "much". Best thing would be to ask the manufacturer. \$\endgroup\$ – Eugene Sh. Oct 26 '17 at 20:42
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    \$\begingroup\$ The adjuster is labelled "stroke" so I would expect it to adjust the amplitude of the vibration rather than the frequency. I suspect @Trevor is right about the 17% slower. \$\endgroup\$ – Finbarr Oct 26 '17 at 20:58
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    \$\begingroup\$ @ThePhoton I agree, but you need a reference to know that it doesn't sound right. For example I have no idea how this thing should sound like :) \$\endgroup\$ – Eugene Sh. Oct 26 '17 at 21:29
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There are two reasons you may have trouble.

50Hz into 60Hz-designed inductors can always be a problem, depending on how conservatively the original 60Hz design was with respect to saturation. If saturation is more than 20% away at 60Hz, then you'll get away with it at 50Hz. If closer, then the core could saturate, drawing many times more current. You can avoid this by transforming the voltage down to 83% of the rated voltage, so 100v, but of course this will reduce the power available.

Vibratory motors will often use a mechanical resonance between the mass of the armature and the compliance of the spring used to support it, to make up for the poor efficiency of that type of motor. If that's the case with this one, then the 50/60 difference could render it completely ineffective. Try it and see.

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  • \$\begingroup\$ Hi, Thanks for the reply. I agree with what you have said. The device is louder and gets warm faster on 50Hz. So the only cheap option he has now is getting a 12V DC to 120V 60Hz inverter. amazon.com/dp/B074DV8YKJ/ref=dp_sp_detail2?psc=1 \$\endgroup\$ – The_Vintage_Collector Oct 27 '17 at 10:58
  • \$\begingroup\$ Also I'm confused about Howard reversible auto transformers that have both 110V/220V conversion can run at both 50/60Hz frequencies without over-heating. As it is also an inductive device like a motor. What could be the possible design changes they have adopted? \$\endgroup\$ – The_Vintage_Collector Oct 27 '17 at 11:01
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    \$\begingroup\$ @RahulSalin A multi-frequency transformer is designed to be OK at the worst frequency for each specification. So for instance the core area is designed for no saturation at 50Hz operation, it will be better at 60Hz. The core material would be rated for core hysteresis losses at 60Hz, and the laminations would be thin enough for eddy current losses at 60Hz, and it then both will be fine at 50Hz. It's not difficult if it goes in at the original design. We often used 50-400Hz rated transformers, consider audio range transformers in tube amplifiers! \$\endgroup\$ – Neil_UK Oct 27 '17 at 12:48
  • \$\begingroup\$ @Rahul, is this $90 12v-inverter the better option? Wouldn't be better if he buys an engraver in the country where he's living now? \$\endgroup\$ – mguima Oct 28 '17 at 14:20
  • \$\begingroup\$ @mguima :D Only if it was just the engraver. He seemed to have taken some other appliances/devices too. He already ordered a $200 3000W 115V 60Hz inverter he told me. \$\endgroup\$ – The_Vintage_Collector Oct 28 '17 at 16:25

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