How to Convert 250vAC to 200vDC 0.05A Output With Zener Regulation and Backup Capacitor

hi guys recently i was searching to build a circuit that converts 250vAC to 200vDC and 0.05A as output.
with a multimeter i measured the source (outlet) and its 225-250 AC then i used a rectifier diode in4007 MIC and a capacitor 400v 2.2uf the output was 338vDC stable (multimeter).
so i was thinking to add a Zener diode 200v 5w and another rectifier diode to protect the Zener.
so please help me to build this circuit and an other thing what capacitance should i use for a 5 second in case of a sudden interruption thank to all of you.

Hi,

Basically, the process is like how to make a power supply, what you need to convert is AC to DC. The simplest way can be done with a rectifier, full wave or half wave. Then comes the filter and finally the regulator. The idea is already there. Just research, there are plenty of examples in the net.