I'm using a 110V→220V foreign electricity transformer (image attached).

Is it possible / safe to mount a power-splitter on the transformer, to allow multiple 110V devices to be connected simultaneously through the same transformer, or should I use a separate transformer for each device?

The foreign electricity transformer I'm using

  • you want to power 220V devices with a transformer which has a 110V output? – Solar Mike Jul 19 '20 at 9:35
  • @SolarMike That's a typo, I meant the other way around. I edited the question. Thanks. – golosovsky Jul 19 '20 at 9:44
  • 2
    Transformers have a maximum power rating. The one in the pic is 90VA. If you use a splitter to power multiple devices from this transformer their combined draw should be less than that. – UmH Jul 19 '20 at 13:51

Is the actual problem "I need to power a bunch of 120V devices" or is it "I have a bunch of gadgets that need correct power" ? There is quite a difference. In the picture, it looks like a power adapter (a.k.a. "wall wart") is plugged in.

  • Many wall warts (or other types of adapters, like "laptop bricks") can actually handle a wide range - e.g., 90V - 240V. If they can handle that range then they will run more efficiently if you simply get a passive adapter that adapts for the type of connection (i.e., the position of the pins) but does not actually change the voltage.

  • Many wall warts (laptop bricks, etc.) produce a standard output. Typical is ~ 18V for laptops with different tips for different manufacturers/models - there are "universal" adapters available that come with a whole variety of tips, such as this Targus adapter:

Targus universal adapter

  • Many wall warts are simply USB power converters. They end with a mini or micro USB connector and there is no need to use the one that came with your device. In fact, plenty of people get extras just to be able to plug the same devices in multiple locations in their house.

I recommend getting a USB wall wart designed for your location that has USB A (the familiar little rectangle you find on most computers) connectors instead of a cable. That way you can just plug in standard USB mini or micro cables as needed for your particular device(s) and, with many of these, charge 2 or more devices at once.


Yes, technically you can do it. You could hook up the secondary to an outlet mounted in a junction box and then just plug the power strip into the outlet.

But this is a bad idea. It would be very easy to forget and turn on too many devices and overload the transformer. Many transformers have thermal fuses that would temporarily disconnect in an overload case but some just have an internal fuse and when it blows, you can't replace it and have to buy another transformer.

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