Cores, light bulb goes on ...

From: allisonp_at_world.std.com <(allisonp_at_world.std.com)>
Date: Wed Apr 28 07:31:32 1999

On Tue, 27 Apr 1999 Philip.Belben_at_pgen.com wrote:

> ><UNTIL you get to about 7.5 amps or so, and then it looks like:
> >
> > No you know what nuts dont work...
>
>
> I don't usually have trouble with American English, but I must confess this
> baffles me. Does it mean something like "Now you know why nuts don't work"? :-)

The First "No" is supposed to be "Now"... Try typing on a -12 baud telnet
link. Edit... took 8minutes to type this sentence and correct one error.
Hell will freeze before the capitalized "f" gets fixed.

> Hows this for an idea. If you find that the toroidal ferrites that Siemens and
> people make don't have enough hysteresis, why not go to the other extreme and
> try the stuff magnets are made of. Ring magnets as used for loudspeakers and
> things are probably a bit large :-) - I wonder if it's possible to drill a
> hole down a bar magnet and then cut slices off. For mass production, I'm sure
> the magnet manufacturers would sell you the stuff unmagnetised...

IT may work. It takes a lot to magnetize that stuff though.

> Now can someone enlighten me: There will be a minor glitch-type delay between
> read and sense pulses with no transition, and a much bigger delay with a
> transition. How do you tell the difference? Is this one of the applications
> where a monostable really is useful?

The prefered digital delay is a delay line, monostables have far to much
timing jitter and drift with themperature to be reliable. They would work
for an experimental setup.

> I think what he meant was: Rather than sending write current through all core
> planes and inhibit current back through those to which you don't want to write,
> why not send write current only through those planes to which you want to write?

If you doing word width usually there is a single x and a single y driver
for the whole array with a seperate inhibit for the bit lines. It's
a matter of *n circuits.

> The other property that affects this is size. The smaller the core, the less
> current it takes to magnetise it.

Yep.

Allison
Received on Wed Apr 28 1999 - 07:31:32 BST