Each LED is 1.8V for a red one or 3.5V for a blue or white one. You forgot to say which colour.
Simple arithmatic shows that the max voltage your LEDs need is (30 x 1.8V=) 54V to (30 x 3.5V=) 105V. Simple arithmatic also shows that you need to drop (220 x 1.414) - 54V to 105V= 115V to 166V.
Calculate the reluctance of a capacitor so that it limits the current to whatever is the rating of your LEDs (20mA?). Then rectify the AC and filter it with a capacitor.
Sorry but I forgot to write I need to drive super bright white leds and Iam sorry to say that I didnt understand anything you said and would a 220nf that is 0.22mfd work and if you mean rectification you say to put a diode bridge and where should i wire the capacitor and please give me a figureand also suggest me a good and free schematic drawing program
(pssst dont take laxatives and sleeping pills together you will experience it)
Help me my amplifier is on fire and my speaker is inside a beaker
Yes! Websites like this are the places you should be going to first. I've learnt that it's much more worth my time going to places that already have the information up for viewing than to come to a forum and ask someone to help me design something. I can't remember ever going to a forum and asking for help in starting a project. In the early days on this forum I would come here only to ask for help on a specific problem I had with my design that I had already made without assistance. It's the best way to do it.
I suppose some people just lack the self motivation that I have. I've been doing electronics since I was a baby. My motivation? The ongoing quest to the "need to know how things work" mindset. I see a battery and a light bulb out of a toy I opened up and I close the circuit with a wire and that's how it started. Now I'm building robots and trying to reverse engineer the brain, but I won't give away to much on that.
Good luck!
When one person suffers from a delusion it is called insanity. When many people suffer from a delusion it is called religion.
A 20W CFL shines bright light all around. But thirty 3.5V white LEDs operating at 20mA have an output of only 2.1W and don't shine all around unless you point each one in its own direction. Then the LEDs will be much dimmer than a 20W CFL.
How to drive leds directly from mains
Posted - Jan 15 2010 : 10:41:41 AM
My motivation? The ongoing quest to the "need to know how things work" mindset. I see a battery and a light bulb out of a toy I opened up and I close the circuit with a wire and that's how it started. Now I'm building robots and trying to reverse engineer the brain, but I won't give away to much on that.