Okay so here is the scenario:
I have 4 rows of A19 LED lights in standard round ceiling electrical boxes in my warehouse, all of them run together into an automated controller. This controller essentially controls the entire environment of the house (i.e. temp, lights, humidity, air movement, everything). The are on 100% intensity from 6am-9pm.
What I need my lights to do is when they turn on, to gradually increase from 0% to 100% over a period of 30 minutes. And similar when they are turning off, remain at 100% all day and slowly dim to 0% over 30 minutes when they go off. I need this to be automated. I don't know what kind of dimmer/timer I will need to do this project. Any assistance or ideas would be much appreciated.

 

Welcome to AAC!

An off-the-shelf solution is to use X10, or equivalent, controllers. They can be programmed to turn lights on/off and can do dimming. I don't know off hand if they dim or brighten monotonically from separate commands; I dim my living room light every evening, but the light is always already on.

 

An important question: Are the lights dimmable? That is, will they respond to and are they safe to use with a TRIAC (phase) dimmer?

ak

 

@dl324 I don't believe anything from X10 will work for my needs. I have about 12 bulbs running on each row. All the rows connect together on 1 wire and are wired into my control box. Most of the products I've seen from X10 are for wall switches, outlets or low voltage devices.

@AnalogKid Yes, they are dimmable. However, I do not believe a TRIAC dimmer switch will work for me due to what I stated above.

My controller box turns on/off my lights automatically. So because of that I just need something to dim them and slowly increase the intensity over a period of around 30 minutes until they are at 100%. I need it to be automated as well. I have only found 1 TRIAC dimmer with a built in timer, but for the timer to work on that product you had to manually hit the button and it only worked in one direction (meaning it only went from 100% to 0% intensity, not the other way around).

 

The dimmable, 120 V AC LED bulbs that I have seen go from about off, jump to 30% to 100 %.
There is on file somewhere in AAC a project to dim-brighten aquarium LEDs over a long period, maybe 60 min.

 

So to clarify, a TRIAC dimmer will work if it can be ramped up and down very slowly, correct?

If so, you can achieve this with a suitable TRIAC dimmer, with the pot replaced by a CdS photocell. With a ramp circuit driving the light source, the dimmer will ramp up and down in phase.

30 min up and down is a loooong time for an analog ramp, but easy for a counter. An 8-bit up/down counter would get you 255 brightness levels, one every 7 seconds. To be really good about equal-valued brightness steps, it would have to be a non-linear D/A converter.

Or, all of the control stuff, including an adjustable user interface, will fit in a PIC, arduino, etc.

ak