It is not economical to bifilar wind all the windings of the transformer together.
Instead a selective bifilar winding technique will be used. The primary winding
will be twisted together with the +24V winding and the +12V and -12V wind-
ings will be twisted together prior to winding them on the core. The +24V
winding will act as the catch winding for the primary and will reduce the voltage
spike during the turn-off of the power switch.
The +5V winding is wound first, distributed equally around the circumfer-
ence of the toroid. ...
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