E
ehsjr
- Jan 1, 1970
- 0
In the thread "Need linear supply 3.3V/15A or 5V/25A"
that Joerg started on 12/2 I posted the idea of rewinding
a MOT for ~6V. I've never done it, but decided to try
it. If anything good comes from it, Joerg gets the credit
because his question planted the seed.
Things went so well with the initial experiments that I
decided to actually make a useful transformer for a
13.8V ~25A (peak) supply.
To do that, I need about 100' of #14 enamelled wire.
(Gonna add 24-30 turns on the primary to knock the
5.62 magnetizing current down to 1.4A or lower. 24
turns knocked it down to 1.4. The secondary will be
3 or 4 18 turn windings in parallel.)
The dissapointment: I found another oven yesterday.
Today I ground off the welds and pried off the primary.
Now, get this: it looks like #14 copper, but weighs
only 6 ounces! It has about 132 feet of wire (based
on turns count x average perimeter of the winding)
The damn stuff must be aluminum.
So I'll have to keep on scrounging until I find one
that has real copper. The rewinding will be a bitch,
so I'm going to wait until I can get the real stuff.
If anyone has any pointers to offer - about the winding,
getting the wire, whatever, I'd love to hear them.
By the way, the ~ 25A is not a requirement. I just
want to get the maximum current I can from it, reaonably.
There's no point in going through the effort for
say 10 amps, and my main experimental interest was in
finding out what it would take to get an MOT into
"re-windable condition" . Now it is sort of a challenge
to try to get the most out of it reasonably. I already
know that Joerg could get his 15A at 3.3 or 25A at 5V
from this xformer. It will easily take 50 feet of #14
enamelled wire, with room to spare.
Ed
that Joerg started on 12/2 I posted the idea of rewinding
a MOT for ~6V. I've never done it, but decided to try
it. If anything good comes from it, Joerg gets the credit
because his question planted the seed.
Things went so well with the initial experiments that I
decided to actually make a useful transformer for a
13.8V ~25A (peak) supply.
To do that, I need about 100' of #14 enamelled wire.
(Gonna add 24-30 turns on the primary to knock the
5.62 magnetizing current down to 1.4A or lower. 24
turns knocked it down to 1.4. The secondary will be
3 or 4 18 turn windings in parallel.)
The dissapointment: I found another oven yesterday.
Today I ground off the welds and pried off the primary.
Now, get this: it looks like #14 copper, but weighs
only 6 ounces! It has about 132 feet of wire (based
on turns count x average perimeter of the winding)
The damn stuff must be aluminum.
So I'll have to keep on scrounging until I find one
that has real copper. The rewinding will be a bitch,
so I'm going to wait until I can get the real stuff.
If anyone has any pointers to offer - about the winding,
getting the wire, whatever, I'd love to hear them.
By the way, the ~ 25A is not a requirement. I just
want to get the maximum current I can from it, reaonably.
There's no point in going through the effort for
say 10 amps, and my main experimental interest was in
finding out what it would take to get an MOT into
"re-windable condition" . Now it is sort of a challenge
to try to get the most out of it reasonably. I already
know that Joerg could get his 15A at 3.3 or 25A at 5V
from this xformer. It will easily take 50 feet of #14
enamelled wire, with room to spare.
Ed