Right. I have the following: A Matrix Orbital MX212 LCD A CCFL (Soon most likely to be two CCFLs) An LED fan Various other fans (not as important) I wish to connect up the CCFL(s) and the LED fan to the GPOs on my MO display in order for me to set it (using LCDC) to turn the items off when my screensaver activates. Now I am thinking I need a relay for this? Especially seeing as I'm already running some LEDs from the GPOs indicating I need to leave the voltage of the GPOs set to 5v? Or does the little voltage jumper on the MO only apply to the high power outputs? Anyway... Will a relay be the answer to this? So the GPO provides power to the relay when screensaver activates which turns off the CCFLs, LED fan, etc? If so, can you please advise which one(s) exactly to buy? Preferably from Maplin? And another thing... Will I be able to power multiple devices from one relay or would you recommend getting a seperate one for each CCFL and fan? And does the same apply for the GPOs? Will one GPO serve more than one relay or will I need a seperate one for each CCFL, Fan, etc? Many thanks for any advice, and if you can think of any better/different methods other than using relays, your input is much appreciated!
over at matrixorbitals forums we have been discussing these very issues off and on...hereMatrix Orbital forums the technical side of it says that a High power GPO (4, 5, or 6 when jumpered) will run 12V devices up to 1000mA each once you hook up the Floppy power plug (as in floppy drive plug). Although most CCFls list current output as 5mA, some specs I have found list current INPUT as 500+mA depending on brand of the inverter. I run 3 pairs of CCFls (as do others) off the 3 High power GPOs at 12V (jumper on only makes 4,5,6 high power, others still 5V). I would guess that as long as your relay can handle the current load (I have one that can handle 3Amps) you could chain a number of CCFls together to flash as one circuit. ie-hook my 3Amp relay up to a 5V GPO for control, provide 12V to the relay load side, and run 4 CCFl dual tube inverters. They would all flash or switch together because they all run off one relay. Whether your PSU can handle that much is another matter. I have a 550watt Antec. Same thing with fans. Hope this helps, go check out the forums for more.
That's a great help, thanks. I have a very powerful PSU (Thermaltake 480W) so that's no problem!! Thing is I only suggested the relays because I wasn't aware the MO could handle such current... Is one really necessary in that case, can I just hook the CCFL power connectors to the high power GPOs?
sure thing...I have 3 dual inverters hooked up right now. On GPO 4, 5, and 6...with the jumper set over to the 12V pins. GPOs 1, 2, and 3 will be used for 5V stuff (none yet) and one relay that will run more CCFls. Just be careful that you relay is an optoisolater or something similar so that you don't send any current back into the matrix. I use a Crydom DMO 063, but it's expensive at $15US each. I can trigger from a low as 3V (handy for using Motherboard pins headers) up to 10V, and can run 0-60V at up to 3Amps on load side. Its small and simple, and I don't know all the diagram stuff. 4 solders and you are done. I bet there is a distributor, just google Crydom, or go to Crydom.com.
Maybe you didn't see fully what I asked Is a relay really necessary if the GPOs can handle that sort of output necessary for a CCFL?
no relay needed- the High power GPOs can handle a dual tube inverter just fine, ONE each. We have some questions about how much each inverter draws, but no one wants to risk burning up their Matrix Orbital by trying it out. However, if you wanted to use a 5V (GPO 1, 2, or 3) you would need a relay to switch up the 12V line.
Oh of course, I was asking about the 5v lines wasn't I. Lol. Right well if this little 12 or 5v jumper only applies to the High power outputs then I'm set. I am a bit hesitant of trying it incase it burns out my little LCD though!
yeah, just read up the pdf on your install disk with the closeups of the back of the unit...it details which are high power and which are not. I had no problems at all with my Rev 1.0- hopefully you have the 1.4, it has fan-plug style GPOs. Much easier to find the plugs for...I had to scavenge some Motherboard style header plugs for mine to work. Good luck, go see the forums...Miles with Matrix is very helpful.
Thanks for the advice It must be 1.0 cos it's got the old jumper-style connectors for the GPOs. Which is good cos I've probably got more of those laying about than fan header plugs. Lol.
ccfl's are inductors iirc so you also want some kind of ferrite thing or diode to stop back emf from killing your display.. - could someone correct me if im wrong, I have a ccfl backlight lcd that im making a regulator for, and need to know if I need to use diodes/stuff and where... You should use a diode for a relay as that also causes back-emf. Dgephri - the reson the output current is only 5ma is because the voltage is stepped up from 12v to ~1.8kv (depends on the inverter). Instead of a relay you can use a transisitor which would be cheaper and from any coil voltage - relays usually want 6 or 12v for the coil.
yeah, I just had to do a lot of searching to even find INPUT current stuff, most only list input voltage, not current...so I had to dig a bit. I don't know anything about the diodes or such...I just called Crydom and told them what I was trying to do, most relays need a higher control load than this one, which will operate down to 3V control (like a motherboard Harddrive header). So it works for what I want, and its simple to solder up.
