Convert 230v 50hz to 100v 60hz

Thread Starter

Allaboutgains

Joined Oct 2, 2015
8
Hi!

I have a hair trimmer from the US that needs 110v, 60hz to work properly. I live in sweden and the local voltage here is 230v, 50hz. With a 230-110v transformer I get the right voltage but the frequency remains at 50hz. So when I turn the trimmer on it gets VERY noisy. And the reason for this is because the cutting part that goes to back and forth hits the edges of trimmer and therefore makes the noise.

A frequency converter is very expensive so I was thinking about buying a 230vac to 24vdc (or 12v) converter with a car cigarette plug. And from there plug a 24vdc to 110vac 60hz converter to the cigarette plug.

Do you think it will work? Or will the 24vdc be converted to 110vac, 50hz because of the fact that I live in Sweden?

Thanks in advance!
 

#12

Joined Nov 30, 2010
18,224
plug a 24vdc to 110vac 60hz converter to the cigarette plug.
It will work and it will be the right frequency. What Dodgydave is talking about is economics. I've seen some awfully expensive trimmers so I can't tell you the math of the money. Now that you know it will work, check the prices.
 

tcmtech

Joined Nov 4, 2013
2,867
Best trimmer I have ever had was a Wahl trimmer kit I bought about 5 years ago for $20.

Still have it and us it weekly for face trimming and my wife cuts my hair with it every few weeks as well. Even use it to trim burrs out of the kitties now and then and still have yet to wear it out or dull it. :cool:
 

#12

Joined Nov 30, 2010
18,224
Read the comments...carefully. There is a lot of crap on the market and it's up to you to try to get your money's worth.

"Turns out the AC frequency fluctuates wildly - during my short measurement I saw it briefly dip to 40 Hz."
 

GopherT

Joined Nov 23, 2012
8,009
@Allaboutgains
If it is an Andis brand trimmer, call them. They have regional repair shops all over the world. Have them swap the motor for you. They only make 2 or 3 different motors. Even if yours I'd for animals - a shop that repairs stylist clippers will use the same parts.


image.jpg
 
Last edited:

crutschow

Joined Mar 14, 2008
33,976
You could also try reducing the voltage to the trimmer at 50Hz to reduce the cutter excursion (and thus the noise).
A resistor in series should work (look at the current draw and choose a resistor value to reduce the voltage by about 15V or so).
Alternately you could add a 220V-12V filament transformer with the output winding in series with the 110V transformer output but with opposite phase (measuring the total voltage will show whether the two are in-phase or out-of-phase).
That will reduce the voltage by 12V which may be sufficient to prevent the excess excursion.
 

Colin55

Joined Aug 27, 2015
519
"With a 230-110v transformer I get the right voltage"
No. The voltage is too high because your trimmer is only taking a very small current. You need to reduce the voltage by adding two back-to-back 12v or 18v zener diodes.
 

crutschow

Joined Mar 14, 2008
33,976
The likely reason for the excess cutter excursion is that the trimmer inductive reactance is less at 50Hz than 60Hz by about 20% so the trimmer current is higher for the same voltage. Thus the suggestions to reduce the trimmer voltage at 50Hz.
 

Thread Starter

Allaboutgains

Joined Oct 2, 2015
8
So if I get it right the easiest and cheapest way of solving the problem is by opening the trimmer and connect a fitting resistor in series with the voltage cable. And by doing so get a voltage divide between the resistor and the magnetic motor of the trimmer?

I have calculated and done voltage division with resistors before in school and it worked just fine. But that was with small currents and voltages and also only DC. It should work just fine now too shouldn't it?
 

ian field

Joined Oct 27, 2012
6,536
Hi!

I have a hair trimmer from the US that needs 110v, 60hz to work properly. I live in sweden and the local voltage here is 230v, 50hz. With a 230-110v transformer I get the right voltage but the frequency remains at 50hz. So when I turn the trimmer on it gets VERY noisy. And the reason for this is because the cutting part that goes to back and forth hits the edges of trimmer and therefore makes the noise.

A frequency converter is very expensive so I was thinking about buying a 230vac to 24vdc (or 12v) converter with a car cigarette plug. And from there plug a 24vdc to 110vac 60hz converter to the cigarette plug.

Do you think it will work? Or will the 24vdc be converted to 110vac, 50hz because of the fact that I live in Sweden?

Thanks in advance!
Most trimmers are just a solenoid with a spring loaded armature that drives the cutter. Use an auto-transformer to get the voltage right and 10Hz difference in frequency will be a trivial inconvenience.

They usually have a screw head on the side to adjust the armature if it buzzes loudly or seems a little too mild.
 

crutschow

Joined Mar 14, 2008
33,976
So if I get it right the easiest and cheapest way of solving the problem is by opening the trimmer and connect a fitting resistor in series with the voltage cable. And by doing so get a voltage divide between the resistor and the magnetic motor of the trimmer?

I have calculated and done voltage division with resistors before in school and it worked just fine. But that was with small currents and voltages and also only DC. It should work just fine now too shouldn't it?
Yes. If you know the current the trimmer draws then you can calculate the resistor you need to drop the voltage about 20%.
Be sure to calculate the power dissipated by the resistor (I * I * R) so that you get the correct power rating for the resistor (at least twice of what you calculate).
 

Thread Starter

Allaboutgains

Joined Oct 2, 2015
8
The specifications on the trimmer says: 15w,115v

The transformer I use gives out 110v 50hz.

So to calculate the resistance and Power of the resistor I want to put in series with the trimmer I get:

I = P/U = 15/110 = 0.136 A
This gives me the current that flows through the trimmer before placing out the resistor.

Since I want 12v over the resistor and the current through the circuit will be 0.136A I get the required ohm size and power:

R = U/I = 12/0.136 = 88 ohm
P = U*I = 12*0.136 = 1.632W

This means the resistor I need to get needs to be 88 ohm and a power of 1.632W?
 

crutschow

Joined Mar 14, 2008
33,976
....................
This means the resistor I need to get needs to be 88 ohm and a power of 1.632W?
Yes.
But for proper derating the resistor should be a 3W.
If that's to large to fit in the trimmer case, then you would have to add it externally, in series with one of the power cord wires, perhaps in an external box.
 
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