Question about the circuit board

[parkertseng]

Hi

I am a new joiner here.
Today I am trying to make some modification to for my hair dryer to be able to use in 220V country from a 100V country.
When I opened the power adaptor.
I can see all the visible parts were label with more than 220V.
Does that mean it is 220V ready?
Thanks

 

[Nigel Goodwin]

VERY, VERY unlikely - if it's suitable for operation on 220V then it will say so on the outside - it's got nothing to do with the voltage ratings on the components.

Generally, to be multi-voltage, a unit would require a SMPSU - which I wouldn't expect a hairdrier to have.

The pictures aren't a power adaptor anyway, they look to be a simple mains filter, to prevent interference.

I would imagine plugging it in to 220V would destroy it in seconds.

 

[For The Popcorn]

Those X2 capacitors are rated for 275 volts. The peak voltage of 220 VAC is 220 × 1.414 = 311 volts – oops, you let out the magic smoke. Rest in peace smoky the hair dryer.

Nigel Goodwin is right anyway – the box is just a filter.

 

[sagor1]

There are 110/220V dryers out there, and are clearly marked as such. Your 100V (120V) unit will not operate directly on 220V, you will burn up the heating elements.

 

[For The Popcorn]

Your 100V (120V) unit will not operate directly on 220V, you will burn up the heating elements.

And the filter caps. And the motor.

 

[sagor1]

It's possible the filter is universal, as the caps are rated 275V AC. But, I suspect the 330V varistor rating is too low for 220V anyway, as they usually have a 10% accuracy, and the peak voltage (311V) would be too much. But regardless, the motor and elements won't survive anyway. The unit is 110V only...

 

[Tony Stewart]

Rated AC voltage is always assumed to be sinusoidal RMS AC not peak or DC. So 275V is OK. and the varistor might blow the fuse with a grid transient.

The heater naturally needs to be increased in resistance by 220 % while maintaining the motor current, so good luck..