As in the question title. Is it possible to generate basic dual rail power from two bridge rectifiers? I tried wiring one forwards and one backwards in a simulator, but I found that it did not work. Does anyone know if it's possible? Instincts say no, because it would require doubling the supply voltage, and that's tricky with just diodes.
Electronic – Is it possible to generate basic dual rail power from two bridge rectifiers
bridgerectifier
Related Solutions
In most cases, paralleling diodes is not a good idea. Their forward voltage drops Vf can be different, if they are not from the same batch. As a result one diode with the lowest Vf in the bank will conduct more current than the rest and more than it's rated for. That diode will get burned. Then the next one will get overcurrent in the same fashion. Untill all of the parallel diodes in the bank are burned. I'm afraid that the quote in the O.P. is describing this [wrong] approach.
But a bridge rectifier could lend itself to a possible workaround. Suppose, you've got 4x bridge rectifier ICs. You must assume that they are not from the same batch. But each of the diodes inside the bridge is from the same batch, because they are on the same die.
Notice that there are parallel diode connections within the bridges, but not between the bridges. No more than 2x bridges can be paralleled this way.
Proceed with caution. Best of all, just get a single bridge with sufficient current rating.
While I have not run any time-based analysis of the described circuit, I see a problem with the ground connection. As you suggest, ground connections are used to connect ground of multiple isolated rectifiers or other floating supplies. However, since both rectifiers use the same input pin (3), they are not isolated from each other.
Since the shared connection creates a virtual node at which voltages at location 2 and 4 are phase-shifted by 180 degrees, the two rectifiers indeed do not work as intended. Try connecting one input between 2 and 4 and the other one between 2 and 3 and see if that would work for you.
Flybacks converter with multiple outputs have usually multiple galvanically isolated winding.
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Best Answer
If the bridge rectifier follows a transformer, and the transformer has a center tap, then the center tap is at the middle (ground) potential. This is the standard linear power supply fpr hifi amplifiers or to make +/-15V for op-amps.