| T O P I C R E V I E W |
| aravindj36 |
Posted - Jan 15 2010 : 10:41:41 AM
Hai how can i drive about 30leds directly from the mains 220v without any flicker and the maximum light |
| 10 L A T E S T R E P L I E S (Newest First) |
| audioguru |
Posted - Mar 30 2010 : 12:49:38 PM
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. |
| aravindj36 |
Posted - Mar 30 2010 : 02:52:05 AM
Mr.Reverse brain engineer I got the circuit from an old book and its giving me light that is equal to one of those 20watt cfl's |
| wasssup1990 |
Posted - Jan 17 2010 : 09:21:47 AM
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! |
| abdulgtm |
Posted - Jan 17 2010 : 05:44:08 AM
Dear Arvin,
I am giving you site where from you can easily get such projects as
www.hobbyprojects.com
hope u will get ur requirement.
abdul |
| wasssup1990 |
Posted - Jan 17 2010 : 04:20:00 AM
Capacitors are vital to know about if you are working with electronics. |
| aravindj36 |
Posted - Jan 17 2010 : 03:23:13 AM
hello mr.john who said that i don't know electronics i just don't know how capacitors work thats all |
| audioguru |
Posted - Jan 16 2010 : 12:19:31 PM
Since you don't know anything about electronics then stay away from dangerous 220VAC. |
| codingplanet |
Posted - Jan 16 2010 : 11:05:33 AM
Firstly you need to know the forward voltage of the specific LEDs you are going to use and also the current you are going to drive them with.
When rectified, 220Vac gives ~310Vdc so the voltage needs to be dropped by around 200-250V.
220nF = 0.22uF not 0.22mF.
A capacitor needs to go in parallel with the output of the bridge rectifier. |
| aravindj36 |
Posted - Jan 16 2010 : 10:43:07 AM
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) |
| audioguru |
Posted - Jan 15 2010 : 7:59:39 PM
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. |
