Also, most power supplies have a voltage adjust. Without the loads connected to the supplies, adjust both supplies to as close to the target voltage as possible (i.e. so both supplies are producing as close to the same voltage as you can achieve (but don't go "nuts"
Then, connect the loads (via the circuit I supplied), and measure the voltages on the anodes of each Rectifier. They should be close to the same (any variance could be due to dissimilar characteristics between the diodes.
Also, as I think about this, because the rectifiers have a negative tempco, the forward voltage will drop as they heat up, and as is the case in nature, no two parts are exactly the same, so one forward voltage is going to drop before the other, and that one will increase the voltage at the cathodes. This will cause three things to happen (simultaneously):
1. Current flow through the other rectifier will decrease (and if it's temperature is above room temp, it will begin to cool).
2. Current flow through the rectifier whose forward voltage dropped first, will rise, causing the rectifier to get even hotter.
3. The sense lines will detect the increase in voltage and each power supply will reduce it's output voltage.
Unfortunately, the power supplies reduction in voltage output won't be enough to cease the heating of the rectifier that is now getting a higher share of the current and it might go into "thermal runnaway", which is not good. The only thing that would prevent melt down is if the power supply has a current limit feature.
I'm not sure if this will happen, but perhaps a small resister in series with each rectifier will prevent this. Something like 10 milliohms at 5 Watts.
