Bathroom extractor fan controler

[Guest Alun]

I've designed this circuit to control the extractor fan in our bathroom. I did originally want to a make it so when the light is turned off the fan stays on for about 5 minutes but my mum didn't want that for some reason. With this circuit you pull the pull switch once and the fan will stay on for 5 minutes, if you pull it twice the fan will remain on until you pull it again.

I've attached a PDF of the schematic, this is my first proper mains project and I want to get it right.

Is the triac alright connected up the way I've shown it?

Which terminal goes to the neutral MT1/MT2 or A1/A2 as some people call them?

I've use a transformer-less power supply, could I use a bridge rectifier to power this circuit so I can reduce the value of the 470nf ballast capacitor or will it mess up the triac triggering?

Fan_Switch_SCH.pdf

[Guest Alun]

I've managed to solve the problem myself.

MT1 goes to 0V.
MT2 to the load.

The triac can be triggered by either posative or negitive pulses regardless of whether the voltage at MT2 is + or -.

I'm thinking of useing a 100nf capacitor for the balast capacitor and a NE7555 for the timer.

There also needs to be a few extra diodes in the transformerles power supply and the 470 resistor might not be needed, I'll post the schematic when I get round to it.