Extractor fan and Pull cord logic

[bathjobby]

Just fitted a new extractor fan which when ordering has many options, 2 of which are as follows;
1) pull cord switch (pull once = comes on, pull again = goes off)
2) pull cord switch with timer; run on time = 2 to 45 mins. Any guesses how this operates ?
Well, I was assuming the same as one except that after the second pull to switch it off it would continue to run until the timer had expired, just like every other one I've had.
Can you belive it, pull once = run for period set internally on the timer. Thats it nothing else and digging deep into the documentation (only after you have bought it) you can eventually figure out that is what it is designed to do. Any one else come across this strange logic or is it just me ?

 

[Qedelec]

BJ, Dimplex do a wall mouted fan heater that operates in a similar way. It only has a pull cord that energises a timer circuit. The timer can be set for 5 to 155 mins by jumpers and the heater rating from 1/2 to 1kW.
Handy for bathroom because it is Class II and user can't touch a switch.