Inrush current limiter: power driven

[shreknel]

Hi guys,

I have a question which I've been looking into but cannot find anything about online.
I've put the reason behind it as a PS so the curious or helpful can read about it there.

I need an AC inrush current limiter (ICL) which is "power controlled" (resets to initial low current passing state when load is disconnected).
I found some models online that support this:
http://www.fg-elektronik.de/en/powersystems/standard-devices/ac-ac/einschalt-strombegrenzung.html

But I wanted to understand how they work, so I tried to find a schematic for them and came up short. (the pdf linked on the previously linked site seems to contain a "voltage controlled" schematic".
The only schematics I found were for "voltage controlled" ICLs (only resets to initial low current passing state when circuit itself is disconnected).
An example of this type is found in the following drawing:

(apologies for the poor picture quality)

My theory is that a small modification to this schematic would result in a "power controlled" ISR:
instead of connecting the "bottom" of the rectifier to the "bottom" of K1, one could connect it to the
"top" of K1 and insert a (measuring) resistor R between this new connection point and F1.

This measuring resistor would then create the voltage drop to power the relay (which would ideally be a 5V or so variant) instead of the
original voltage over K1. When the AC current would drop to 0, the relay would not be powered anymore and the current would have to flow through
the NTC resistors again.

If anyone has any more insight into this topic, I'd be very grateful to learn a bit more about this topic.
thanks!



PS: reason why:
I'm planning on purchasing an inverter generator (http://en.wikipedia.org/wiki/Engine-generator), which I want to use for emergency power.
Now, I need to let the generator do a little bit of work once every month to avoid it getting clogged and jammed.
I anyway need to mow my lawn or do some work in the garden with electric tools, so I wanted to use it to power those.
However, I want to stay well below the limits of the inverter and this is not so easy with highly inductive loads which have high inrush currents