All works as expected and on the zener I have exactly 15 V rectified. Later, one day after, I've discovered that even with the AC power (230V) disconnected on the C1 capacitor there were about 5 residuals Volts. For this reason I've short-circuited the capacitor with the purpose of completly discharge it. This, probably, was my big mistake because after that the circuit stops working and I've discovered that the bridge rectifier was irrimediably broken and shot-circuited. Frankly I don't understand why this it happened and how to improve my circuit to prevent a similar event in the future. Any idea? Thanks in advance.
ADD: Reading all replays an comment I suspect that the circuit is not so good. Neverthless, I've forgetted to say that before that the bridge rectifier broke down, I've connected an oscilloscope probe across the zener and by this way I could see that there was a residual 5V voltage on the capacitor. I don't know if that can explain what is happen...
I've a significant update to my issue.
After I've added the bleed resistor and replaced the fried bridge rectifier, than I've replugged the AC power and all seemed to works fine too.
I've connected the multimeter and all measures are right.
At this point I've connected the oscilloscope probe and puff... the bridge rectifier was fried too.
The oscilloscope is a Tektronix TBS1000C Series, brand new, just purchased and works fine even after the issue described.
Nevertheless I've a suspect.
The circuit that mount the bridge rectifier is connected to the power wall outlet (230V) while the oscilloscope is connected to an APC Smart UPS.
All like the following layout:
I don't know if this could be the reason of the issue and, especially, why. Any other idea?