Inrush current limiting module for SMPS

[eem2am]

hello,

i am making an offline SMPS.

When i switch on there will be inrush current so i want to limit it. -but not using an NTC as it has no protection when SMPS is repeatedly power cycled.

However, the limiting circuitry will otherwise be a lot of components.....relay, relay driver, resistor, power supply for relay etc
...or if i use a high side mosfet to switch the inrush resistor out then that will need a regulated isolated voltage of its own....many components.

are there any inrush modules that can just be bought off the shelf?

i have looked widely but found nothing.

thenks in advance

 

[vomit]

smps inrush current

If you use a high side p-channel mosfet, you can use a zener/cap/resistor to ground to have soft start without extra voltages > Vinput. The R/C to perform the actual soft start, the zener to limit the gate-source voltage to whatever the FET requires.
The only disadvantage would be a slightly larger Rdson, but I don't know the power of your application and if that would be a problem.

 

[eem2am]

inrush current smps

thankyou....actually i need the switch to be in front of the emc filter....since i wish to also stop inrush into that....so it will be in the ac line.

im amazed there appear to be no offtheshelf modules

Looking at the following

**broken link removed**

this is typical of all manufacturers......40 Amps of inrush for a 150w Converter.

40 Amps.....put them all on together and down goes the national grid!

does any reader know of offtheshelf inrush limiters