still researching ...
Hi All
I'm still busy trying to get my head around all the valuable info you have offered and definitely am taking the time to read through as much as my already overloaded mind can take !
Melanie and anonymouse thanks for the tip regarding the fuse on the NEUTRAL line :-) , I have updated the schematic to reflect only a single fuse on the LIVE line !
And thanks again Melanie for the info regarding the OPTO and the TRIAC,
the reason the TRIAC is open ended is because I have not decided what value to use for the TRIAC, since I think this may be dependent on the choice of PIC (and PORT) ? The designs I have seen so far seem to indicate somewhere between 470R and 1000R for the TRIAC resistor (R3 in my diagram).
Two things should me taken into consideration here :
1. the TRIAC gate currents (MIN and MAX)
2. the PIC pin allowable current
PLEASE CORRECT me if I am wrong!
In the meantime I am reading through this as a start!
http://www.microchip.com/stellent/id...pnote=en011202
What's of concern is that Microchip have made no mention (that I can see) of the differences between a COMMON NEUTRAL or COMMON LIVE design in the appnotes !!
Steve,thanks again for the tip especially for the transformer info ... READ the posts to date very carefully please... we have already established that the Microchip design is a COMMON LIVE design which 'floats' 5V below either 120VAC or 220/230/240VAC and that it would be a whole lot 'safer' to rather 'float' 5V above NEUTRAL, hence the changed design thus far.
Also as Dave pointed out, I did mention in post 1 that I would like to use a transformer-less PSU.
Dave .. thanks so much for the continuous valuable x10 references as well as the tips thus far.
That appnote sure has a lot of info and someone went through a huge amount of work to setup the application to get it to that stage I'm sure (especially looking at the section for the tuned circuit replacement of the usual x10 120KHz tuned transformers), is that mains injection being done purely with a resistor and a cap ?
I saw a project a few days ago where the designer is injecting a 135KHz pulse into the carrier and was wondering if that could be done with the pulsin pulsout command instead? Will see if I can find it for you since I think it may interest you as well.
Dave and Melanie (and anyone else)... regarding a zero-crossing sensor (which may be needed for dimming), where would you best situate it in this circuit ?
I have seen various designs indicating it in different places, and most have one of the PIC pins connected with a resistor in series directly to
For all those following this thread, please note that nothing has been built as yet and the attached schematics are merely used for the discussion.
Please also take note of ALL the safety warnings!
Thanks to everyone for all the info so far!
Kind regards
Dennis
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