FlapJack
Full Member level 6
How can this power supply possibly work. It is called a Stacked switching regulator. It is an non isolated topology that uses 208 V 3 phase for an input and an output of 3.3 KW, 330 VDC at 10A.
It's claim to fame is that most of the power passes directly through from the 3 phase rectified line to the output. The regulation is handled by a small inverter run at 25 KHZ with a square wave. The inverter primary is center tapped and supplied with a variable DC voltage controlled by the feedback loop.
The output of the inverter is a single secondary in to a bridge rectifier across a 400 uF 100 V capacitor that is in series with the 208 3 phase rectified line.
The 3 phase line is 208 VAC x 1.732 = 360 VDC - diode drop. For this circuit to work the capacitor has to pass the DC from the 360 VDC and somehow buck 30 VDC doing it.
I can see the inverter output driving the 400 uF capacitor to 30 VDC and it's polarity bucking the 360 VDC but that is assuming that the 360 VDC supply could pass through the capacitor. Capacitors are supposed to block DC!!!
Maybe it is a flux capacitor.
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BTW in the post there are 3 separate pictures labeled page 1, page 2, and page 3, it just looks like one big picture, hover your mouse over the thumbnail to see the file names.
It's claim to fame is that most of the power passes directly through from the 3 phase rectified line to the output. The regulation is handled by a small inverter run at 25 KHZ with a square wave. The inverter primary is center tapped and supplied with a variable DC voltage controlled by the feedback loop.
The output of the inverter is a single secondary in to a bridge rectifier across a 400 uF 100 V capacitor that is in series with the 208 3 phase rectified line.
The 3 phase line is 208 VAC x 1.732 = 360 VDC - diode drop. For this circuit to work the capacitor has to pass the DC from the 360 VDC and somehow buck 30 VDC doing it.
I can see the inverter output driving the 400 uF capacitor to 30 VDC and it's polarity bucking the 360 VDC but that is assuming that the 360 VDC supply could pass through the capacitor. Capacitors are supposed to block DC!!!
Maybe it is a flux capacitor.
- - - Updated - - -
BTW in the post there are 3 separate pictures labeled page 1, page 2, and page 3, it just looks like one big picture, hover your mouse over the thumbnail to see the file names.