Hi Everyone. I'm making a arduino controlled fluroscent dimmer. I thought of using traic and pwm. But some forums suggest pwm only work with DC.
Please suggest an energy efficient method to control fluroscent lamp. Please son't post any code in here. Link's would be handy
An easy way to do it would be to get a pre-made light dimmer and use something like a servo to control it. Just be careful that the fluorescent lamp that you end up using is a dim-able one, many of them are not and trying to dim them will damage them.
An optoisolator & TRAIC works with AC incandescant bulbs by switching on the current for part of the AC cycle. I don't know much about dimming fluorscent lamps, except that method doesn't work... 
One complication is, at low levels you have to keep the starter filaments powered-up, and a simple TRIAC-based dimmer will reduce power to the filaments.
You might want to do some research about how fluorsecent lamp dimming works before you jump-in.
I found [u]this electronic ballast[/u] that works the same as high-powered LED dimmers - It uses a 0-10VDC control voltage to adjust the brightness.
With a ~10V power supply, a transistor or MOSFET, and an RC filter, you can convert the Arduino's PWM output to a variable DC control voltage.
using a triac along with just pwm will not work for dimming. As far as AC controlling goes, your AC runs as a sine wave. A positive side and negative side (the middle point is called the zero cross point), if you do not control the zero cross (blank signal during this time) you will not get a clean sine wave output, this causes the light to become more like a strobe light (not effects you want on the system, may cause burnout or fires). The rest of the circuit needs a zero cross detector (look at IL250 and MOC3021 chips). These chips are called opto-isolators (opto for LED light inside the chip, Isolator controls based off the light, isolating one half of the circuit from the other). A clear example of modules already out on the market can be found at http://www.inmojo.com/store/inmojo-market/item/digital-ac-dimmer-module-lite-v.2/ (make sure to find a model using a IL250 instead of a 4n25, 4n25 uses only one led in the chip instead of two) There does come a downside to using this, (one way I'm trying to correct) you need to use an interrupt instead of PWM (messes with other critical processes on the chip, halts everything on the chip to process the zero cross)
I just also looked into florescent lighting, CrossRoads tells the what florescent lighting is and how it works http://arduino.cc/forum/index.php/topic,155722.0.html , it goes from AC to a DC level back to a high frequency AC using multiple rectifying and manuipulation . You may be able to manipulate the conversion from the DC to high freq AC to dim the lighting through PWM. I'll do some research into this and get back asap