Rlim in GZ33 datasheet?

[jarthel]

here's the datasheet: http://www.mif.pg.gda.pl/homepages/f...129/g/GZ33.pdf

I wonder if it's the same as the Rs (surge limiting resistor) in the Bendix 5839 datasheet (see the schematic on page 2
: http://www.mif.pg.gda.pl/homepages/f...131/5/5839.pdf).
Also is it needed?

thank you for the replies.

[Tom Bavis]

This is the resistance that must be provided to limit peak current if the maximum input capacitor is used. You don't need to add a resistor if the effective series resistance of the transformer (secondary plus reflected primary resistance) is high enough. PSU designer will calculate this value if you fill in voltage, primary and secondary resistance.

What REALLY matters is staying within the peak current rating of the tube. If you have a high enough transformer resistance, you can use 470 uF capacitors and the rectifier tube won't care. Conversely, if you have a very low transformer resistance, you may need to use less input capacitance to avoid overstresing the cathode. Exceeding the peak repetitive current rating is likely to cause arc-over. PSU Designer will show the peak current for you.