nvic wrote:

I was curious about inverters too. I use 120v (US). You said you had a
story, can you tell it?

The half power series diode on hair dryers ?

A customer of my client who had one of their amplifiers I designed complained of a
noisy mains transformer. I think they sent a replacement but he said it was the same.
I visited the guy and it turned out that it was a problem only when his girlfriend's
hair dryer was on ( at half power ).

I deduced that his mains supply had a high impedance and the half wave rectification
of the hair dryer was enough to add a dc component to his ac supply which caused
excessive current in the transforrmer primary that in turn resulted in a line
frequency hum.

Not actually funny ha-ha but funny odd.

I left him to figure out how he wanted to fix it.


Also, would you mind explaining how these work.

To keep it simple. An inverter makes ac from a low voltage dc supply by various
techniques using semiconductor power devices and then steps it up to mains voltage
using a transformer. The wavefrom is rarely as purely sinusodal as your wall socket
though.

Graham