a little help with capacitive power supply values

[Byte_Butcher]

Gee suddenly this thread has quietened down :-(

There were no explosions, no loud bangs , nothing that went bump in the night...

Gee, that's kind of anticlimactic after all the DANGER warnings, now isn't it?
No conflagrations = Congratulations.

The questions now are :
1.Is it the TRIAC gate resistor causing the flicker ?

Maybe. Honestly, I think I'd use an opto-isolator to drive the triac. But that's just the way I am...

2. Are there any suggestions for the the value for R3 ? (Check earlier posts for BT-139 gate current values and specs.

Refer to answer #1...

3.Cap C1 value is 275V and I'm thinking rather to use a 400V rated X2 instead, any thoughts on this ?

If your mains is 220V, then I 'd use a 400V rated cap. No way, on the 275V.

4. What's a concern is in times of NO LOAD , what will life be like for the PIC control PIN and the TRIAC gate ?

Not quite sure of the question here, but I think it goes back to answer #1

5.Other options include using an opto-isolator (possibly a MOC3023 or 30XX) in conjunction with or stand-alone ..any thoughts ?

Hmmm. Yeah, I think an opto-isolator would be good.

Steve ... are you ready to measure ? ;-)

Rat's, and I just sent my nomex suit to the cleaners and loaned my 10' insulated pole to my neighbor.


Say, don't you think it might be a good idea to put a small 5 volt zener from pin 5 to ground? I know that 1M is a pretty high value resistor and the PIC pins have some protection against over-voltage, but there's something kind of creepy about just connecting a PIC port pin to that high of a voltage, even through a big resistor. Probably no big deal, but it makes me nervous connecting that pin to 220v with just a resistor.


steve

[Dennis]

Hi all

OK 8 hours of flashing a 60W light bulb and no issues yet , Im feeling a little 'strobed-out' though :-), battling to decide to watch the light or the LED :-)

I'm also more keen on the OPTO , just wondering how it will survive the capacitive 5V floating circuit on the PIC side of things ... will explain more a little later.

Regarding the PIC for zero-crossing sensor , have you read the Microchip appnote 236a ? It should make you feel a little more confident , but I can try a diode if you like ?

Now about those screen caps and measurements :-) haul out that isolation transformer and scope and let's get some more info :-)
If you are curious and have the time of course ..

Kind regards

Dennis

[Byte_Butcher]

Regarding the PIC for zero-crossing sensor , have you read the Microchip appnote 236a ? It should make you feel a little more confident , but I can try a diode if you like ?

Nope, haven't read it. But I will in the morning.
But if it's OK with the folks at Microchip, then I guess it's OK with me.

I will read the appnote tomorrow... zero crossing detector is one of those things that will come in handy for me someday.

steve

[Dennis]

Hi all

Steve ...
Also check out the posts by Dave Houston regarding the x10 info ... they have indeed been using an MCU's for many years and I recall seeing a post or two by Dave referencing certain models in particular even a PIC 12XXXX if I'm not mistaken.

You could also always conduct AC testing on low-voltage 'downlights' (not sure what you call them in the US or Europe ... ?

Keep those posts coming , this is a very interesting thread so far :-)
Oh and see post 66 (clickety clicks :-) )

Oh .. and last but not least a popquiz question... Am I using a COMMON LIVE design or a COMMON NEUTRAL design ...and why ?

Kind regards
Dennis