John Fields wrote in news: snipped-for-privacy@4ax.com:
So what IS the story, exactly? Right now you've focussed on the results of a load (the resistor), so you've said things that might be taken to discredit the rest of us who specified that either peak has an absolute value of voltage across a capacitor that when unloaded, must be considered for its safety. While a half-wave rectified form is a more complex wave whose RMS value needs a different calculation, in this case it's the separation between peaks that matters.
Many PSU capacitor failures seems to be a result of people underspecifying the working voltage while assuming they'll be 'safely' loaded to prevent the peak from dictating terms more than the RMS. It's not a safe assumption.