Can a dimmable LED bulb be connected to Arduino Uno without a dimmer needed? Does it have a built-in dimmer circuit?
Have a look at the Fade example in the IDE
Led bulb as in 120V/230V bulb? You may be able to change it to use DC but they need a high voltage most of the time so it's not easy.
The Adruino has not dimmer circuit but it has PWM outputs which you can use to drive normal led's or led strips via transistors.
kumbhrageri:
Can a dimmable LED bulb be connected to Arduino Uno without a dimmer needed? Does it have a built-in dimmer circuit?
You should provide details of all hardware you refer to in your question, ie which LED bulb?
MarkT:
You should provide details of all hardware you refer to in your question, ie which LED bulb?
Okay! Consider the following specifications
LED Down Light (Dimmable)
Input Power: 14W
Input Voltage: AC90-300V,50Hz
http://syskaledlights.com/led-down-light-dimmable-14watt.html
Still unable to tell from that. You might be able to remove the driver and add your own but you probably need a high voltage.
What you can do is make a mains dimmer. BUT that is messing with mains and mains can and will kill you if you're not careful and don't know what you're doing.
And an extra note, a lot of mains dimmable leds (especially the cheapies) dim terrible because they use the rectified mains 100Hz/120Hz to dim which is noticeable, especially with movement. But for example all Ikea led bulbs I tested dim with a higher frequency. Don't know about this one though.
For any typical LED bulb that says dimmable, does it mean it can resist constant change in its intensity or it can be directly controlled using arduino based on its specifications? In general.
Mains bulbs can't be directly controlled by an Arduino. They are designed for phase angle dimmers which we use for incandescent and halogen bulbs as well.
You should be able to find [u]AC Dimmer[/u] examples using the Arduino. AC dimming with the Arduino (or other microcontroller) requires an electrically isolated TRIAC and an electrically isolated zero-crossing detector.
AC LED bulbs have a power supply inside. Unless you are using a commercial AC dimmer, it's usually better to get a "plain" (low-voltage) high-power LED and a [u]dimmable 'constant-current' power supply[/u]. That way, you can avoid all of the zero-crossing/phase-control stuff. The industry standard for dimming these supplies is a 0-10V or 10V PWM control voltage. The Arduino can supply 5V PWM, and you just need to add a 10V source and a little transistor or MOSFET circuit.