<Any idea how to estimate the gauge? I know I'd need red and green enameled
<perhaps another color like yellow? I also wonder what they used to insulat
<the splices? It appears to be some kind of paint.
You'll have to mic it once the diameter is known you can look it up give
or take the enamel insulation.
<What size nuts?
Small, looked like #2.
<Oy! The core circuit that I copied for my 12th-grade drafting project use
<7.5VDC as the half-voltage. How much oomph would it take to induce a stabl
<magnetic pattern in a steel nut?!? I would think that enameled insulation
<would cook right off the wire.
Keep in mind using say 30ga wire and the current could be in the several
amps range as it's a pulse (a big one!). The total time would still be
short. For a practical example a suitable ferrite could be used and there
are plenty of suppliers.
To do it with steel (not iron) nuts you'd have to do some pulse testing
using one and a single turn of wire to find the switch point (push it
with a bipolar narrow pulse). a second wire (a few turns) can be connected
to a scope. Increase the drive to the first wire until you see it start
switching. the BH switch point will be noticeable if the core has usable
hystersis (fails otherwise). A good material for this is hypersil commonly
used for transformers. I think the cores of the late 50s used that with a
dimension of 50mils OD and about 5turns of 0.1mil thick material. Large
cores are less critical and give a bigger kick as a responding signal.
The penelty is that large cores switch slowly and have really big half
select currents. The latter is not a problem with modern semis but in the
late 50s early 60s transistors that could switch fast were also too slow
and tubes didn't switch high currents well. mades doing core very hard.
A tidbit of design history extrapolated from design of the TX2 (an
Electronics Design article).
Allison
Received on Mon Apr 19 1999 - 21:59:17 BST