mike wrote:

I'm assuming there's a minimum load for the power take-off to work
properly and I've never noticed before because I've never connected
such a low-wattage tool. Is that right?

It would seem to be the case. It might use a current sensor to detect
when the tool is in use and the small tool was just not drawing enough
continuous current to keep it activated.

But what's the deal with the extension leads?

It is a so called "Transmission Line" effect. You can think of the
length of wire as a long chain of very tiny inductors and capacitors
that can store a small amount of energy. When connected to the power you
will get a very small current flow into the lead that will in effect
cause it to charge and discharge in sync with the AC supply. However
since you don't control exactly where you are in the AC cycle when you
connect the lead, you may happen to pick a point where the voltage is
close to its peek value (340V) - this can result in a very brief but
substantial current flow - possibly enough to trigger the current
sensor. Since there is no actual load other than the wire this current
flow is not sustained and hence it shuts off straight away after.


--
Cheers,

John.

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