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I have a soldering station designed for 110V AC only. I live in Europe so I have to convert it to 220V AC if I want to use it. I thought to sell it but the shipping is huge (it weights 3+ Kg) so probably I would just waste my time.

Its internal power transformer has a label with the following info:

  • Model: YF-EI 66x36
  • Input: 110V/60Hz
  • Output: 10V 26V 30V (I couldn't verify this since I don't have 110V main AC but hopefully the info matches the transformer's outputs)

So I see only 2 solutions:

  1. buy a step-down voltage transformer from 220V to 110V that would provide at least 700W (this is probably the most expensive solution)
  2. buy a new power transformer from 220V to 10V/26V/30V and replace its internal power transformer with this one (this seems somehow cheaper than the other solution)

What would you suggest for this situation? Some advice/tips?

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closed as off-topic by Chris Stratton, Voltage Spike, Enric Blanco, Dmitry Grigoryev, Trevor_G May 25 '17 at 21:38

This question appears to be off-topic. The users who voted to close gave this specific reason:

  • "Questions on the use of electronic devices are off-topic as this site is intended specifically for questions on electronics design." – Dmitry Grigoryev, Trevor_G
If this question can be reworded to fit the rules in the help center, please edit the question.

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    \$\begingroup\$ I doubt you will even find a transformer to buy with those exact specs... \$\endgroup\$ – pipe May 23 '17 at 21:00
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    \$\begingroup\$ You'll probably save yourself a lot of headache (and possibly even repurchasing your soldering station) with a 220/110 converter. I found several 1000W options on Amazon for under $100. Seems like it'd be worth it to look into that route if you're not going to sell it. \$\endgroup\$ – Chris M. May 23 '17 at 21:10
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    \$\begingroup\$ " that would provide at least 700W" Really? A 700 watt soldering station? And it ONLY weighs 3 kg? Are you sure you haven't multiplied 110 volts times 60 Hz, and called that power? \$\endgroup\$ – WhatRoughBeast May 23 '17 at 23:13
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    \$\begingroup\$ @EugenMihailescu - I'm just having trouble with your description. A 700 W iron would be enormous. For instance, here americanbeautytools.com/Soldering-Irons/19https://… is a 550 W iron which weighs 2+ kg, not including a transformer. and a 500 VA 60 Hz transformer will run something like 8 kg. So something in your description does not add up. \$\endgroup\$ – WhatRoughBeast May 23 '17 at 23:53
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    \$\begingroup\$ @WhatRoughBeast I suspect the hot air gun element is powered directly off the mains. The transformer probably only powers the 75W iron and the control electronics (and perhaps the air gun motor). \$\endgroup\$ – Bruce Abbott May 24 '17 at 0:38
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You don't need a transformer, but an autotransformer. An autotransformer is very cheap compared to the transformer. It has one winding that is split into two. One winding has larger gauge thickness, while the other is thin. The core isn't such big as transformer. Last time I had dealt with an autotransformer was a 3kVA 480V/400V, it was the size of my palm.

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  • \$\begingroup\$ Now that (1) we've clarified that the YF-EI 66x36 is a 50VA transformer and that (2) the 700W mentioned refers the hot air gun heating element which bypass entirely the 50VA transformer being connected to the mains, the problem seems to be solved. On Aliexpress/eBay one can found various 220V autotransformers that provides 10/26/30V outputs or very similar. Thanks @MarkoBuršič \$\endgroup\$ – Eugen Mihailescu May 24 '17 at 18:23
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Step-down transformers for this purpose are quite common. Check under "expats" on Google. I had several of these during my couple of European assignments. Smaller transformers are sold as razor adapters and larger transformers are sold in areas where there are US military bases as they will convert the voltages for TV's and other higher current appliances. If the base has a local sale/swap board, you will find them there as people move back to the US and want to unload them. I obtained several 1 kW versions for free with this method. In fact I still have them thanks to the company paying my moving expenses but unfortunately shipping one to you wouldn't be cost effective.

You may also have some success with a lamp dimmer. Connect the dimmer to the mains and adjust the output voltage for 110 Volts. Continue to monitor its output voltage and plug in and briefly turn on your soldering station. Don't use this solution however, if your soldering station has a motor for a vacuum pump as the motor won't be happy with the chopped sine wave.

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  • \$\begingroup\$ How about this crazy idea: power the 110V transformer at the 220V main. What would be the outputs? The "10V" output will output 20V, the "26V" will output 52V, and the "30V" will output 60V. By adding a voltage divider at each these outputs I would get the exact voltage that the circuit board is looking for (ie. 10V/26V/30V). Do I miss something? It couldn't be that easy, right? \$\endgroup\$ – Eugen Mihailescu May 23 '17 at 22:16
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    \$\begingroup\$ Yes, you are missing the power dissipation in your voltage divider. Likely the resistors would have to be huge, and the regulation would be poor, possibly causing issues. \$\endgroup\$ – John D May 23 '17 at 22:30
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    \$\begingroup\$ Agreed that the power dissipation would be a problem. If your station takes 700 watts at 110 volts, your resistors would have to dissipate another 700 watts. \$\endgroup\$ – Glenn W9IQ May 23 '17 at 22:42
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    \$\begingroup\$ Your transformer would burn up if you tried to regulate the secondaries. The primary may not even handle the double voltage. The lamp dimmer is much simpler and more cost effective. Just make sure it is rated for +700 watts. \$\endgroup\$ – Glenn W9IQ May 23 '17 at 22:46
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    \$\begingroup\$ "this crazy idea: power the 110V transformer at the 220V main." - yes, that is a crazy idea. The transformer will saturate and blow the mains fuse (if you are lucky) or burn out. A light dimmer is unlikely to work properly on a device like this which has complex electronics in it. \$\endgroup\$ – Bruce Abbott May 24 '17 at 0:33

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