I've got a shaking dog here

[Walt Longmire]

I used my Milwaukie cordless tools last night. Put the batteries on the charger today. Dog hates it. She is right next to me shivering like she is shitting peach pits. This is a 75 pound Golden Pyrenees that will blood trail wounded bears. Scared of the charger. 

[Glocks4Freedom]

Sewing machines, chargers... WTF!

[XSIV4S]

The noise or vibration must touch on some primal fear, I wonder what it is?

 

[Walt Longmire]

3 minutes ago, Glocks4Freedom said:

Sewing machines, chargers... WTF!

Let's not forget the pressure cooker either.

[Boogieman]

A nuclear event could occur next door and my Mastiff would just fart and go back to sleep.

[janice6]

Many of the new semiconductor "circuits" use an inverter principle in the power supply.  To make the components cheaper and smaller, they use a much higher frequency than the 60 Hz power line, which means that they can use smaller and cheaper transformers and circuit components.  The frequencies are very high and some go higher than human hearing so you don't hear the squealing like the old TV Flyback transformers had.

My guess is that it is very high audio frequency and the dog can hear it and it's driving him nuts.  His hearing is being bombarded by it.

[Walt Longmire]

10 minutes ago, janice6 said:

Many of the new semiconductor "circuits" use an inverter principle in the power supply.  To make the components cheaper and smaller, they use a much higher frequency than the 60 Hz power line, which means that they can use smaller and cheaper transformers and circuit components.  The frequencies are very high and some go higher than human hearing so you don't hear the squealing like the old TV Flyback transformers had.

My guess is that it is very high audio frequency and the dog can hear it and it's driving him nuts.  His hearing is being bombarded by it.

I think the whistling of venting steam on the pressure cooker may do the same thing. Don't know about the sewing machine or the Roomba.