I'm at a conference and the only plug is a "Uni Pak II" which is a dimming power source (here's the manual).

At first my charging indicator on the end of the MBA plug didn't light, but I slid up the analog slider and it lit up (I knew it had worked yesterday!).

Is there any chance of it harming my MBA or power supply to use this?

2 Answers 2


I make no guarantees here.

Probably no harm will come to the MBA. The power is buffered through the transformer in the power adapter. You might burn out your power adapter if you vary (dim) the voltage while it is in operation.

I would also strongly suggest not plugging in the power supply to the adapter until you have adjusted the adapter to full power.


In general, it isn't a good idea to put a power adapter on a light dimmer as the circuitry could malfunction if the voltage is too low.

That being said, I believe the 45W adapter for the MacBook Air will survive- it just won't charge if the dimmer reduces the voltage below 100 volts. The AC is converted into DC and then applied to a voltage regulator circuit which typically shuts down when it isn't getting enough.

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