# Transformers headroom and “mandatory” components

I have calculated the maximum (Worst Case) current consumption of my circuit to be 88mA. Looking at transformers I found one at an specified max output current of 90mA for parallel winding which is my case. The next available component has a max current output of 200mA.

Q1: am I cutting it too short if I select the 90mA transformer? is there any derating that I should take into account such as temperature or saturation current as for inductors?

Q2: On the primary winding connected to AC mains. Are elements such as a fuse and a Y2 capacitor mandatory to pass electrical certifications?

Thank you

• what is the measured current consumption? – Leon Heller Jul 30 '18 at 10:51
• The circuit has not been built. Is the analytical calculation of the WC consumption – RWeiser Jul 30 '18 at 11:47

• The output DC level from a bridge and capacitor is the RMS AC voltage into the bridge multiplied by $\sqrt2$ and then subtracted by 2*0.7 volts. That is at full load and of course there will be ripple to consider. – Andy aka Aug 1 '18 at 8:58