Inductor Core Saturation and Losses

[ronsimpson]

Off line isolation:
Lets assume the neutral wire runs through your box and is the (-) probe.
Lets assume the hot wire runs into your box.
The (+) probe is at 30 volts above neutral.
Neutral is near ground.
Looks good!

Some nut removes the ground wire. AND/OR Your house is old and only has two wire. OR Some one mis-wired the outlet.
Now you (-) probe is at 110 volts. AND You die.

I would use a full or half bridge forward power supply. (may resonant) Run it at 250khz. Use a 10:1 transformer running at 250khz so the transformer is small. Input 120VAC, 170VDC @10A, transformer 17VDC @100A. That I can do. The transformer also makes isolation.

 

[johansen]

you could still kill yourself standing barefoot on a steel plate and putting your hand into a bucket of electrolysing salts at 20 volts lol..
safety is relative.

i managed to zap a friend of mine with 700 volts last week it was unintentional ... i warned him about the magnet wire sticking through the motor casing.. vibrating against the sharp edge of the aluminum case..
we were both thinking "who's going to be the first to get shocked" at the time.

 

[samovar]

Neutral wire is bonded to ground. When it goes positive, your "afer rectifier" (-) wire goes negative relative to it. Therefore you get half-cycle AC between ground and your (-) wire. This sure can kill.

Since your load's (+) is only 12 volts away from (-), you also get almost entire half-cycle AC between load's (+) and ground. This can kill too.

The only safe way is isolation.

Any thoughts on the source for inductor cores?

 

[johansen]

if you want to go with a high frequency 50Khz and up, just use the ferrite cores out of scrap computer power supplies. you can also use the powdered iron cores from the same, but they have higher losses, but over twice the energy density.