Powering CCFL bulbs? - Page 1
Forum section: electronics / beginners

author: Josephur
author_rank: Newbie
timestamp: September 03, 2015, 06:51:34 am
content: I tore apart a Vizio E420AR LCD TV.. to harvest it for it's good main board and power board to sell on eBay since the screen was shattered.I got all the boards out and what I'm left with is a lovely white/light box with 10 900mm CCFL bulbs behind it, I would love to use this for a back lighted sign since it has a nice mounting bracket on the back of the unit, and is bright. The thing is I've never ran a CCFL bulb off of AC before at all, and none of the voltages seem to be on the accompanying power/driver board that is still attached, where do I start?I'm familiar with Arduino and Raspberry Pi, but I think this will require high voltage(?), and really all I need is for the lights to just stay on constantly to light up whatever content I want to place on top of the diffused white panel that lies in front of the bulbs.I'll provide some pictures once I get some feedback and decide if this is easily done or not. Thoughts?, ideas?

author: Zero999
author_rank: Super Contributor
timestamp: September 03, 2015, 09:22:59 am
content: If it's really an LED TV, the it shouldn't have a CCFL bulb in it.

author: Josephur
author_rank: Newbie
timestamp: September 03, 2015, 10:08:49 am
content: I wrote this when I was tired.. It's an LCD

author: amyk
author_rank: Super Contributor
timestamp: September 03, 2015, 02:45:24 pm
content: Search eBay for "CCFL inverter".

author: Connoiseur
author_rank: Regular Contributor
timestamp: September 03, 2015, 04:13:30 pm
content: If you don't mind running it from a battery, (anything in the range of 6V to 24V will be great; and it would be much safer than working with mains) you can build a royer oscillator based ccfl inverter with just a few off the shelf components. It is very efficient if built properly. The parts you need are:1)A pair of NMOS 2)transformer with CT primary, feedback winding and secondary all on ferrite core 3)Ceramic cap 4)Resistors

author: Josephur
author_rank: Newbie
timestamp: September 04, 2015, 01:11:52 pm
content: I think the inverter is still embedded to the board the bulbs plug in to, the only thing missing would be the microcontroller that controlled the bulbs starting up. It has test points all over it too, just not sure how to probe them correctly to figure out which pins are juice and supply the right amount. I'll post pics soon. Thanks for the feedback so far.

author: iamdarkyoshi
author_rank: Frequent Contributor
timestamp: September 04, 2015, 03:07:57 pm
content: If its anything like my monitors, there should be a pwm pin from the logic board that controls the backlight. I have LED retrofitted a couple CCFL monitors in the past and I needed to find a way to control the LED's regulator.

author: Cliff Matthews
author_rank: Unknown
timestamp: September 07, 2015, 04:37:27 am
content: Just sell the main board, the power supply / invertor board is worth just $25See:http://www.shopjimmy.com/vizio/e420arYou'll also find a second stage invertor with one inductor per tube under a plastic cover on one side (fed from the main PSU board, which has a VBL voltage of 80v)