Hi All.
I need a SMPS for my metering application for three phase network where input could be anywhere between 100Vac & 460Vac.
SMPS should shutdown if the voltage reaches over 506Vac & also there should an output OVP.
My output are as below.
1. 4volt@20mA for TI metering chip (3.3V LDO will be used thereafter)
2. 18V@50mA for driving a latching relay (1000 uF capacitor will be charged through a 100ohm resistance via this supply, Latching relay coil impedance is 100 ohm & worst case relay driving frequency will not be more than 1 per minute).
3. 6volt@50mA for isolated accessories.
Here I am using STP1N105 mosfet in TO-220 case as a switch.
Plz help me by verifying the SMPS design attached herewith & also i need understanding on design of transformer required with this SMPS. Design calculator is only providing Primary inductance & turn ratios. Using this data how can we construct the transformer.
In this case i need transformer based on EFD20 size core.
rgds