Slow fade-in circuit

Given that this is an electronic design forum, we should design something. I could start. Maybe some others can suggest circuits.

How much power are the LED lights, in total?

A triac dimmer typically won't see a low enough impedance when dimming some LEDs. I have one string of LED spots, with one incandescent left to make the dimmer work.

theater, suddenly turning on the lights is a somewhat unpleasant experience . I want a simple circuit compatible with 110 volt dimmable LED lights tha t will slowly ramp the light output over a period of about 5 seconds or so. I have found a number of simple designs that would work for 12VDC LEDs, b ut none for 110VAC dimmable LED lights.

I would design using modules. I already posted a link to two. Done and du sted!

Since when is Larkin actually concerned about discussing electronic design other than when he intends to use it as a put down for someone? That is a truly nasty individual.

It's no wonder that Larkin is not respected by many here. On a personal le vel he is the sort of person the world would be better off without. But he has a highly specialized skill in a corner of electronics design that stil l has some minimal demand, so the world pays him to do that.

How many is many? Have you taken a census?

You are a good contributor to the group, Ricketty, except when you're not. There are not that many people here that dislike Larkin. He, too, is a good contributor. He does not post the kind of diatribe as you have done. You do much better at describing projects than you do at this kind of attack. Please take my post as constructive criticism.

theater, suddenly turning on the lights is a somewhat unpleasant experience . I want a simple circuit compatible with 110 volt dimmable LED lights that will slowly ramp the light output over a period of about 5 seconds or so. I have found a number of simple designs that would work for 12VDC LEDs, but none for 110VAC dimmable LED lights.

I thought of something like this, but the power dissipation seemed high. Thinking about it a bit more, maybe not so much.

You're right about that. I wasn't thinking straight. The highest power di ssipation is across RT, and that will only be for the few seconds when the light is at minimum power. If performance using a leading edge dimmer is g ood enough, this may be a viable solution.

I would just use an SMD Full Wave Bridge. I have lots of them.

I can get FMMT38C darlington transistors for under $0.10 to take care of Q

Let me take a look...

"Not many" translates as "None of the cool kids _I_ hang out with", as used in middle school playgrounds the world over. ;)

Cheers

Phil Hobbs

can't you just replace the smart switch with a smart dimmer and have the sm art controller manage the dimming? Are you saying you can't find those at a ll? Is the switch an integral part of the fan?

The fan controller handles three speeds for the fan and on / off for the l ight. If I remove the fan controller, then I no longer can control the fan .

Four lights x 5 watts = 20 watts per fan

That wouldn't be horrible.

no. but terminals, strain-releif, and insulation will take up most of the matchbox size leaving very little room for any active parts. those things scale with wire-size and voltage, you have not indicated a willingness to negotiate on those parameters.

y can't you just replace the smart switch with a smart dimmer and have the smart controller manage the dimming? Are you saying you can't find those at all? Is the switch an integral part of the fan?

s With Alexa, Google, INSTEON"

e, INSTEON"

r box next to the one for the fan.

Those ae very expensive, but there are less expensive ones. Of course, it means splitting the mains feed and bypassing the existing light controller . That is doable, of course, but it is a bit of a waste and not a very goo d fit. I don't want to sit there and give a dozen instructions to get a sl ow fade-up. Those are Insteon controllers, by the way, not IFFT. I would have to buy an Insteon hub, and then it would require a different controlle r.

Do you feel like building a circuit? It could be done with 5 discrete parts, or possibly 3.

It's really easy to make some people angry and preachy. Just ask them to design something.

rk theater, suddenly turning on the lights is a somewhat unpleasant experie nce. I want a simple circuit compatible with 110 volt dimmable LED lights that will slowly ramp the light output over a period of about 5 seconds or so. I have found a number of simple designs that would work for 12VDC LEDs , but none for 110VAC dimmable LED lights.

d dusted!

ign other than when he intends to use it as a put down for someone? That i s a truly nasty individual.

l level he is the sort of person the world would be better off without. Bu t he has a highly specialized skill in a corner of electronics design that still has some minimal demand, so the world pays him to do that.

Fine, but it's not accurate. There have been any number of posts by Larkin responding to nothing in particular by others where he talks about his dis favored few being "nasty" and other choice terms. That was why I used the term.

It is rather un-evenhanded to call my two, short paragraphs as a "diatribe" but ignore the many ugly posts by Larkin.

That's on you.

y can't you just replace the smart switch with a smart dimmer and have the smart controller manage the dimming? Are you saying you can't find those at all? Is the switch an integral part of the fan?

light. If I remove the fan controller, then I no longer can control the f an.

So don't remove it, just replace the light part.

Or find a remote that is intended for the fan and also dims the light. Sil ly of the original maker not to.

I installed a fan for a restaurant once. It was fairly high end, Hunter I think. It had a mode where it ran the speed up and down, dimmed the lights up and down and played music!

It is hard to imagine they aren't out there. Everything else is.

why can't you just replace the smart switch with a smart dimmer and have th e smart controller manage the dimming? Are you saying you can't find those at all? Is the switch an integral part of the fan?

rks With Alexa, Google, INSTEON"

gle, INSTEON"

-222/204380623

her box next to the one for the fan.

it means splitting the mains feed and bypassing the existing light controll er. That is doable, of course, but it is a bit of a waste and not a very g ood fit. I don't want to sit there and give a dozen instructions to get a slow fade-up. Those are Insteon controllers, by the way, not IFFT. I woul d have to buy an Insteon hub, and then it would require a different control ler.

I don't follow your thinking. The waste has already happened, you bought a product that no longer suits your needs. Adding a follow on dimmer is no less a waste than replacing the light control with one that is effective in your new task.

I don't know what you are talking about "dozen instructions". If you don't understand how this stuff works then maybe it is a bit much. A dimmer sh ould be able to bring up the lights slowly without multiple inputs from a p erson.

I don't know what IFFT is. Some acronym you like or a brand name??? They may have the Insteon name on them, but the point is they can do the job. I spent 2 minutes looking. If you spend a few more minutes I'm sure you can find something that won't invalidate your homeowner's fire insurance like a home brew project would.

Yes, of course! I am having a little trouble imagining only 5 components, let alone 3, but I am game to look at anything.

I did find a nice, small buck converter module that is only 7mm x 4.5mm wit h up to 450V input and 300ma output. It only requires 13 external componen ts, all of which can be 1206 SMDs except for a small inductor. This makes a trailing edge MOSFET based dimmer using a 555 practical. It's $2.24, but I can handle that.

Hmm, yeah my mind first assumes some DC supply. Maybe ~120V DC supply and resistor divider... and then something like a 555... integrator then comparator/ reset.

George H.

matchbox

Oh, nonsense. The only thing that will carry any significant current is th e output stage, which consists of either a Triac or a pair of MOSFETs. Tho se will be TO-220 cases sitting off the board. They probably don't even ne ed heat sinks, given the small current they will be carrying. There is no need for any insulation other than that provided by the board itself and th e plastic case. I won't use terminals. The wires will solder to the board .

Oh, yeah. Wire size. The fixture is intended to utilize four 5 watt bulbs . That's 20 watts, or 0.167 amperes. Allowing for NEC rules, we apply a f actor of 1.2, or 0.2 amperes. Even 32AWG wire can easily handle more than that, but I won't go that low. I will use 18AWG stranded wire, which can h andle up tp 16 amperes (over 2000 watts) in free air.