Need LED strip lights that are dimmable. - Page 1
Forum section: electronics / general

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: March 21, 2012, 09:41:09 am
content: Hi.I've got a large room and on three of the four walls I'd like to put LED strip lights atop long, thin pieces of timber up about 7 feet off the floor. I've got no problems doing the job or buying the lights:http://www.brightlightautoparts.com/NEW_LED_LIGHT_STRIP_LIGHTING.htmlMy problem is the lights are advertised "not dimmable". The minister of war and finance has approved the job but demanded that they also be dimmable. So I've got two 6 metre walls and one 8 metre wall to do.Btw, one of the existing walls already has a light strip bank on it of fifteen year vintage and is perfect for what I want to do by replacing the lights then continue around the rest of the room with new timber and new lights and extra new wires to them where required.The existing bank is a 6 metre long strip of 24v 5w festoon lights. The transformer in the roof is a monster (as you'd expect) and I realise it would have to go if I change the lights. Wiring to the light existing light is adequate. The switch also has a standard clipsal 500w 240v dimmer that looks like it has been getting a little warm.So the existing circuit -is- dimmable. I was going OK with everything until I hit the no dimming roadblock.What to do?

author: eddydde
author_rank: Newbie
timestamp: March 21, 2012, 10:35:15 am
content: I think you will find most led strip lights can be dimmed with the correct dimmer. I have used several light strips that use pwm for dimming in my 747-400 flight simulator.Go to ebay and search for led light dimmer and you will see one unit that comes out of Hong Kong for Aus $5 delivered. 12volt 8 amps.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: March 21, 2012, 10:38:45 am
content: Thanks will check that out.

author: eddydde
author_rank: Newbie
timestamp: March 21, 2012, 10:44:02 am
content: If you havnt yet purchased your strips of leds they are available at a fraction of the price on ebay out of Hong kong. I have purchased 15 metres of them of various colours.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: March 21, 2012, 10:52:50 am
content: Quote from: eddydde on March 21, 2012, 10:44:02 amYou haven't had any trouble with the lights failing too early? How long have you had them (how many hours on)?

author: Psi
author_rank: Super Contributor
timestamp: March 21, 2012, 11:05:15 am
content: I've bought leds from this website beforehttp://www.hebeiltd.com.cn/It's direct from some of the LED factories in china so the prices are good (although i've not really looked at their led strip prices).They mark any items that use budget leds with the label "X-Type" so you know its not intended for critical products.Ive never had any issues with their quality and they sell LED strips, both X-Type and good quality ones.And they have the datasheets

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: March 21, 2012, 11:09:02 am
content: Quote from: Psi on March 21, 2012, 11:05:15 amGood to know. Ta. How do you dim yours?

author: Psi
author_rank: Super Contributor
timestamp: March 21, 2012, 11:13:09 am
content: Quote from: Ed.Kloonk on March 21, 2012, 11:09:02 amPWM from a mosfet connected to a microcontrooler.PWM is the best way to control LED brightness

author: T4P
author_rank: Super Contributor
timestamp: March 21, 2012, 04:51:08 pm
content: PWM is the best way to dim and no , NONE of the LEDs are not dimmable .It's how you dim it , clearly if you use a triac dimmer on the led driver circuit , it will fail quickly .There's two methods , resistance method ( those big ol' VRs ) which is frankly stupid .And PWM , which is the best and you get off shelf for a few bucks from china .None of the LED strips i bought from China has failed , running 24/7 for 1 year now .