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Lee,
The sinusoidal (multicycle) waveform is easily eliminated with a simple
series diode which prevents the current from flowing backwards in the coil.
I have found that works well with capacitor-discharge magnetizing circuits
for permanent magnets. So this turns off the polarizing field just as it
tries to reverse. If you want the peak intensity to remain longer, you must
also prevent the capacitor from charging in reverse, using a second diode
(reverse biased) connected in parallel with the capacitor. Basically this
forces the peak stored magnetic-field energy to be dissipated in the coil
(maintaining a decaying but non-alternating field) rather than
reverse-charging the capacitor. Of course it is necessary to match the
voltage of the capacitor with the number of turns on the coil, its
resistance, and the desired flux density. If one capacitor has sufficient
energy (making series capacitors a waste) then smaller-C capacitors can be
connected in series to provide the same energy with higher voltage.
Best regards,
Peter
----Original Message Follows----
From: "Lee Fraser"
Reply-To: "The Proton Mag Forum"
To: "The Proton Mag Forum"
Subject: Re: Bifilar windings
Date: Fri, 19 May 2000 17:51:28 -0300
The Proton Mag Forum
Peter
I was just thinking about a capacitor discharge and drew out the equivalent
circuit ( an inductance, a resistance ( didn't add one for the capacitor)
and a capacitor. This is a tank circuit and most likely the only thing it
will produce is a exponentially decaying sinusoidal waveform. Yes low cost
BIG capacitors are available but check out their voltage rating. You
haven't lived until a capacitor blows up in your face.
Now if you thing CD has merit then I would like to see a design that I can
build that clearly deals with the turn off of the polarizing field. Also a
capacitor is a voltage device so when it is switched into the discharge path
(through the coil) its terminal voltage will be determined mostly by the
resistance of the coil thus limiting the current.
__________________________________________________ ____________________
The sinusoidal (multicycle) waveform is easily eliminated with a simple
series diode which prevents the current from flowing backwards in the coil.
I have found that works well with capacitor-discharge magnetizing circuits
for permanent magnets. So this turns off the polarizing field just as it
tries to reverse. If you want the peak intensity to remain longer, you must
also prevent the capacitor from charging in reverse, using a second diode
(reverse biased) connected in parallel with the capacitor. Basically this
forces the peak stored magnetic-field energy to be dissipated in the coil
(maintaining a decaying but non-alternating field) rather than
reverse-charging the capacitor. Of course it is necessary to match the
voltage of the capacitor with the number of turns on the coil, its
resistance, and the desired flux density. If one capacitor has sufficient
energy (making series capacitors a waste) then smaller-C capacitors can be
connected in series to provide the same energy with higher voltage.
Best regards,
Peter
----Original Message Follows----
From: "Lee Fraser"
Reply-To: "The Proton Mag Forum"
To: "The Proton Mag Forum"
Subject: Re: Bifilar windings
Date: Fri, 19 May 2000 17:51:28 -0300
The Proton Mag Forum
Peter
I was just thinking about a capacitor discharge and drew out the equivalent
circuit ( an inductance, a resistance ( didn't add one for the capacitor)
and a capacitor. This is a tank circuit and most likely the only thing it
will produce is a exponentially decaying sinusoidal waveform. Yes low cost
BIG capacitors are available but check out their voltage rating. You
haven't lived until a capacitor blows up in your face.
Now if you thing CD has merit then I would like to see a design that I can
build that clearly deals with the turn off of the polarizing field. Also a
capacitor is a voltage device so when it is switched into the discharge path
(through the coil) its terminal voltage will be determined mostly by the
resistance of the coil thus limiting the current.
__________________________________________________ ____________________