Re: Magnetic Rectifier??

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

Original poster: "rheidlebaugh by way of Terry Fritz <twftesla-at-qwest-dot-net>" <rheidlebaugh-at-zialink-dot-com>

A capacitor can also limit the reverse dc current flow.  When Antonio said
robust he was not kidding.
Robert  H

> From: "Tesla list" <tesla-at-pupman-dot-com>
> Date: Sat, 02 Mar 2002 20:32:35 -0700
> To: tesla-at-pupman-dot-com
> Subject: Re: Magnetic Rectifier??
> Resent-From: tesla-at-pupman-dot-com
> Resent-Date: Sat, 2 Mar 2002 20:45:51 -0700
> 
> 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
> 
> 
> 
>