Re: Magnetic Rectifier??

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz <twftesla-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>

Tesla list wrote:
> 
> Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-qwest-dot-net>"
<evp-at-pacbell-dot-net>

>         Are you saying that a reactor, with the core saturated in one
direction
> by a DC magnetizing force or a permanent magnet will have a steady-state
> DC component in the current which can flow through it when an AC voltage
> is impressed?  Gotta think that through some more, but don't see how
> that could happen.  Don't have a simulation program which includes a
> model for saturation, and am trying to figure out an EASY experiment.
> Gave plenty of magamp cores of all sizes, so might be able to rig it.
> More discussion please.

The idea is to insert an inductor in the AC path, that has an extra 
winding where a DC current is applied (a magnetized core would work too,
but a DC current adds easy control). A transformer with AC in one coil
and DC in the other. The inductor would normally
present a high impedance to the AC circuit, with little current flowing
through it. When the sum of the magnetic fields produced by the DC
and AC currents causes the inductor core to saturate, the inductance
falls to a low value, and the AC current flows more intensely.
Since the bias is DC, the "inductive switch" will operate at just one
side of the AC cycle. The resulting current will look as a small AC
waveform (sinusoid) with high current pulses at the centers of the 
swings of one polarity. The width of the pulses can be controlled by
the DC current. These devices are very robust, although not very
efficient. I have seen they used in (rather old) high-power battery 
chargers, with a diode connecting the AC+pulses current to the
batteries. 
(Without the diode, the battery would generate a DC current flowing
back through the inductor and the AC power transformer, limited only
by wire resistance).
These devices are still used in many applications, including
high-voltage
switching.

Antonio Carlos M. de Queiroz