Hi,Can you decouple AC into a floating ground via a capacitor?
I still unclear about the nature of this floating ground? In order for the bypass (or decoupling capacitor) function to work there must be a complete circuit of some sort so energy can move into that alternative (shunted through) usually low impedance path instead.I guess the short version of what I'm asking is can I bypass the voltage rating of a capacitor in a ripple filter by filtering into floating ground?
This is where IMO you are going conceptually wrong (with it's origins in the water analogy). The currents don't flow into a ground reference point like water out of a facet never to be seen again or fill up a tub. The electric current behaves more like links in a bicycle chain that move in a closed loop to transport energy from source to load. The power supply ripple currents must have a closed loop to return to the their source for the shunt to work.Well seeing how ltspice does't allow floating circuits I can't post a schematic. Not sure how I can explain it any more simply.
Capacitors are used in power supplies to shunt ripple currents into ground.
The only return path for C8 current would be in series to the very small L1:L2 transformer coupling capacitance or leakage currents. The Galvanic isolation breaks the current loop 'chain'.
I agree. The L2 circuit could be at any voltage compared to the L1 side and it wouldn't matter. That's the beauty of isolation! The capacitor would change that relative voltage by a small ±∆V, and it still wouldn't matter to an ideal circuit.
The short answer is no.
It does not.The AC power sources signify the AC from the wall. Even though the bottom circuit is floating the current still returns to the wall through the transformer does it not?
You are wasting yours and our time. The current path that actually allows C8 (or some equivalent total capacitance) to filter the ripple current from the positive side of the bridge needs to be directly connected to the negative side of the full-wave bridge to be effective.
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by Jake Hertz