On Wed, 30 Apr 2014 11:51:29 +0000, alan.b.pearce@stfc.ac.uk wrote:
:: Are you saying the secondary centre tap is connected to one end of
:: the winding, creating a shorted section of winding ???
Correct, see my reply to Russell for a more full explanation.

:: The TRIAC is connected across the mains terminals?

Sorry, I should ahve been clearer (well it was clear to me, I had the=20
circuit in front of me). connections are via the fan - one side to the fan,=
=20
other side of fan to N, other side of triac to L, G direct (via 510 ohm=20
resistor) to uC.

:: to make driving a TRIAC easy without having to use isolated drive

Bingo, I didn't think of that, but opto isolators are relatively cheap, but=
=20
I suppose in thousands it does add up.

Colin
--
cdb, colin@btech-online.co.uk on 1/05/2014
=20
Web presence: www.btech-online.co.uk =20
=20
Hosted by:  www.justhost.com.au
=20
=20
This email is to be considered private if addressed to a named  individual=
=20
or Personnel Department, and public if addressed to a blog,  forum or news=
=20
article.
=20
=20
=20



--=20
http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist
.