In this video at the 1:57 mark the narrator says he converted the two halves of a center-tapped transformer winding into parallel windings for use with a full bridge rectifier:
My question is would there be any significant difference between doing that and just using a two diode full wave (non-bridge) rectifier leaving the windings in series?
The configurations being compared are shown in this document:
http://www.hammondmfg.com/pdf/5c007.pdfas "FULL WAVE Capacitor Input Load" and "FULL WAVE BRIDGE Capacitor Input Load".
The formulas on that page suggest that peak DC voltage remains the same, but that the "I D.C." will be about 20% more for the full wave bridge configuration -- assuming that parallalizing the windings will double your current capacity. Is that right? Are there any other factors to consider?
It's all about winding resistance, which correlates with core aperture.
For a center-tapped, two rectifier layout, only one half of the secondary is supplying current at any time, which is inefficient.
With the parallel secondary, bridge rectifier layout, the secondary is utilized fully. You'll have one extra diode voltage drop, which is only an issue at low secondary voltages.
My feeling is, that the 20% figure is a bit optimistic, my estimation would go towards 25%, but this is very dependent on transformer size.
Higher utilization of the transformer V.A rating with a full bridge rectifier
than with a full wave rectifier.
look at the two configurations below (capacitive filter)
FullBridge we can get 1.41*0.62 = 0.874 of the transformers V.A rating
FullWave we only get 0.71*1.0 = 0.71 of the V.A rating
So ~ 16% better utilization.
As Benta posted a fullwave is only using 1/2 of the transformer winding on each half cycle whilst
a fullbridge is utilizing the whole winding on each half cycle.
At lower secondary voltages though the extra 2 diode voltage drops of the fullbridge rectifier will constitute a greater portion of the available output power so at this point a fullwave becomes relatively more efficient.
regards.