Ummm... Fun one Fansler, David wrote: > > Darren - I do not pretend to be an expert - but here is what I see. > 1. The schematic does not totally match the article > 2. The load would go between Hot Out and Hot In. I don't like the "hot out" term at all; Originally I was misled, here - I'd expect the load to go between Hot Out and Return, given that terminology! Hot In is power from the power grid, and, Hot Out is pulled towards Neutral/Return from Hot In by that Triac, to light the bulb - so I'd have called that Lamp Return instead, or something like that. So yep, David's right, and this is just plain murky terminology Not an electrician, I guess? > 3. You would supply a Neutral (white wire) to Return. > 4. You would supply Hot (balck wirefrom power company) to Hot In > 5. Ground (green) is a good idea. It can be tied to Neutral (which is > done in US breaker boxes). Definitely a good life-saving idea. > 6. Vcc is generated by the circuit above the PIC (RV1, R1,2, C1-3, > D1-3) > 7. I would take JP1 to be an external input to allow control of the > circuit by an outside source (another PIC, automation system, etc.) For safety, I'll add this: If you're going to use JP1, please DO verify that "Neutral" isn't hot with respect to the Ground line, before or during installation; If it is and you connect a switch pair to J1, touch a lead on that & grab something that's grounded, and you can be killed. So - please be a little careful there! Probably a good idea to verify that anyways, I've seen a few mis-wired houses. (Some with 3-prong outlets throughout the house, none having ground wires attached, almost bought that place... Would've run ground wires soon!) > 8. While simple, a fair warning is given in the article that this > circuit has no isolation from the AC main and therefore can bite you! > 9. If used for lighting purposes, this circuit will produce filament > hum at low light levels (larger filaments hum more) A large choke in line > with the load will kill the hum. Have it hum "Singing in the rain" for us Seattle area webbed-footed folks? > David I'll add another finnick: I just plain *detest*, dimmers that come on "Full Bright" when the light's "off". BAD idea; I lose my night vision so as I later walk down the hall, I step on the cat & get bit & scratched, trip on the cat scratching post, step on the sharp metal piece the cat knocked off the shelf and bleed on the carpet, and by then I'm getting "displeased"... With Full On, I get far more light than I want or need, it wastes energy (as I dim the light way down & leave it on all night, instead of turning the light OFF, due to the huge annoyance of losing night vision) - and it's really hard on the bulb! I'd have the bulb come on at 10% or so, and ramp up fast if the user holds down "Brighter", but not full on to start with; Ick. I've heard the excuse, "But - full on, instantly, will scare a burglar worse"; I seriously doubt it, a sane burglar is going to be FAR more concerned about an occupant turning the light on to 20% - so they still have night vision, and can still see to chase the burglar, or to get into position inside the place to hold them for police, far easier than with the lights coming on full brightness - so the occupant's Blinded completely, I'd think. If you blow a bulb up, that might spook the burglar more; Why use a dimmer circuit to blow bulbs up, though? Use it to extend bulbs' life, instead! Mark > -----Original Message----- > From: Darren King [mailto:darren.king@SYMPATICO.CA] > Sent: Wednesday, December 08, 1999 2:44 PM > To: PICLIST@MITVMA.MIT.EDU > Subject: Microchip Appnote Dimmer Problem. > > http://www.microchip.com/Download/Appnote/Category/rDesigns/40171a.pdf > > > I have looked at the above 100 times and I'm still confused. I don't really > want to build this circuit without understanding it. I really hope somebody > could help with this one. I'm not familar with the Hot in - Hot Out -Return > (White). When I see White I know what that means. So which of the hot in > and hot out is supposed to be the black? Is the green wire used? Does the > load hook up between the Hot Out and the Return? What is Vcc supposed to > be? Is this where I hook up the load? What is RV1? As you can seem I'm > not an electronics wiz, but understanding this would help out greatly. As > you can read, I'm really lost. > > Darren King -- I re-ship for small US & overseas businesses, world-wide. (For private individuals at cost; ask.)