Any tips for toroidal transformer winding. ?

[N_Cook]

Power type with iron and copper between 2 and 3 Kg. Thick gauge of wire so
hand winding using shuttle. Any ideas on a rotate and lock (for a few turns)
external support system (cobbled together not full engineering) and passing
shuttle horizontal or vertically for ease of use ?.

 

[bz]

Power type with iron and copper between 2 and 3 Kg. Thick gauge of wire
so hand winding using shuttle. Any ideas on a rotate and lock (for a few
turns) external support system (cobbled together not full engineering)
and passing shuttle horizontal or vertically for ease of use ?.

Some ideas that may help you. Some have been used successfully winding
smaller toroids.

Use a 'throw away' tie wrap to give you a handle with which to hold the
core.
You can clamp the tie wrap in a fisherman's fly-tying vice and position the
core in a convenient position, with the hole horizontal.


Pre-cut wire to length needed. (calculate amount needed or estimate from a
trial run using short piece of wire). Better to end up with some excess,
rather than too short. Use the 'average length' for a turn. Average turn
length will be the average between the minimum length (a turn snug against
the core) and the maximum length (pad the core to simulate maximum number
of turns of wire already wound).

When winding, pass half your wire through center of core.
Then alternate winding turns with each end of the wire.
Pull each turn 'tight' so you don't run out of room for the wire.

Be careful not to pull too tight and damage the insulation on the sharp
edges of the core. You may want to remove the sharp edges with a file or
the corner of a whet stone before you start winding your wire onto the
core.

You can use a short section of thin tubing, such as that salvaged from an
old telescoping antenna, as a 'needle' to push/pull the ends of the wire
through the center of the core if the wire isn't stiff enough to serve as
its own needle.

Start with the wire doubled if you want to wind 'two windings' of the same
number of turns.



--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

[email protected] remove ch100-5 to avoid spam trap

 

[N_Cook]

Some ideas that may help you. Some have been used successfully winding
smaller toroids.

Use a 'throw away' tie wrap to give you a handle with which to hold the
core.
You can clamp the tie wrap in a fisherman's fly-tying vice and position the
core in a convenient position, with the hole horizontal.


Pre-cut wire to length needed. (calculate amount needed or estimate from a
trial run using short piece of wire). Better to end up with some excess,
rather than too short. Use the 'average length' for a turn. Average turn
length will be the average between the minimum length (a turn snug against
the core) and the maximum length (pad the core to simulate maximum number
of turns of wire already wound).

When winding, pass half your wire through center of core.
Then alternate winding turns with each end of the wire.
Pull each turn 'tight' so you don't run out of room for the wire.

Be careful not to pull too tight and damage the insulation on the sharp
edges of the core. You may want to remove the sharp edges with a file or
the corner of a whet stone before you start winding your wire onto the
core.

You can use a short section of thin tubing, such as that salvaged from an
old telescoping antenna, as a 'needle' to push/pull the ends of the wire
through the center of the core if the wire isn't stiff enough to serve as
its own needle.

Start with the wire doubled if you want to wind 'two windings' of the same
number of turns.



--
bz 73 de N5BZ k

please pardon my infinite ignorance, the set-of-things-I-do-not-know is an
infinite set.

[email protected] remove ch100-5 to avoid spam

Thanks, thats more than I'd found googling. I think its beyond a fly-tie
vice. I was thinking of some slabs of lorry innertube fixed to the jaws of
a Black & Decker workmate and work at the side edge of the workmate. Maybe
use softer rubber, only at the thought experiment stage at the moment.
Doubling up is probably ok for secondaries but I'm not a believer in
doubling up for primary windings , too much voltage over too little laquer.

 

[Robert Macy]

Thanks, thats more than I'd found googling. I think its beyond a fly-tie
vice.  I was thinking of some slabs of lorry innertube fixed to the jaws of
a Black & Decker workmate and work at the side edge of the workmate. Maybe
use softer rubber, only at the thought experiment stage at the moment.
Doubling up is probably ok for secondaries but I'm not a believer in
doubling up for primary windings , too much voltage over too little laquer.

--
Diverse Devices, Southampton, England
electronic hints and repair briefs , schematics/manuals list onhttp://home.graffiti.net/diverse:graffiti.net/- Hide quoted text -

- Show quoted text -

If this transformer is to be used for a 'mains' transformer, like an
isolation transformer - DO NOT DOUBLE UP THE WIRE!

first wind a prmary
then layer well with kapton tape
then wind secondary

you may also find that you will need to add an extra turn(s) to the
secondary to make up for losses and get the voltage through as 1:1
under load.

Robert