bigt0706
New member
u will only run one posative and on negative to the ballast so posative on led 1 and negative on led 80 ,u will jump the rest between the first posative and the last negtive of each series ,
Diy led
- Thread starter flworkd
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u will only run one posative and on negative to the ballast so posative on led 1 and negative on led 80 ,u will jump the rest between the first posative and the last negtive of each series ,
brassmonkyballs
BMB
Other Considerations When Connecting in Parallel
Other Considerations When Connecting in Parallel
I wanted to pass on another thought about connecting in series parallel.
The failure mode of an LED will usually be open (not necessarily but normally). In other words if something happens and one LED fails then the connection to the string will stop at the bad LED....sorta like christmas tree lights the entire string goes out. When this does happen what do you think the result might be?
Remember the explanation on how to know the current of the driver down by making parallel strings? Divide the total current of the driver by the number of strings right? So what happens if one LED fails on one string? That string just disappeared from your circuit and the current is redistributed to the remaining strings thereby potentially over driving you remaining LEDs!
What to do......Its generally a really good idea to put a fast blow fuse on every string to protect it in the event something opens up.
keep it mind.
Other Considerations When Connecting in Parallel
I wanted to pass on another thought about connecting in series parallel.
The failure mode of an LED will usually be open (not necessarily but normally). In other words if something happens and one LED fails then the connection to the string will stop at the bad LED....sorta like christmas tree lights the entire string goes out. When this does happen what do you think the result might be?
Remember the explanation on how to know the current of the driver down by making parallel strings? Divide the total current of the driver by the number of strings right? So what happens if one LED fails on one string? That string just disappeared from your circuit and the current is redistributed to the remaining strings thereby potentially over driving you remaining LEDs!
What to do......Its generally a really good idea to put a fast blow fuse on every string to protect it in the event something opens up.
keep it mind.
jimmy_beaner
New member
So, I've heard a lot about wattage of certain types of lighting not being equal. I'm really wanting to try to retrofit an LED fixture into my Biocube 29 hood... but how many LED bulbs should I be looking for? 24 LEDs right now would get me the same wattage, but I have a sneaky feeling it would be way more light than is actually there now. Upgrading from PC lighting to LED would be amazing.
brassmonkyballs
BMB
Forget about wattage comparison....apples and oranges and the PC lighting in the Biocube couldn't compare.
The # of LED depends on the type of LEDs. Cree would be no more than 20. These FEDY would be around 30.
jimmy_beaner
New member
Thanks. I'll try to swing by Lowes and see what they would have that might function for a heat sink and structural unit to house the LEDs. I've gotta assume that this will end up "paying off"
brassmonkyballs
BMB
It will pay for itself but read through this thread to see what people are doing. Go to RapidLED.com to see the packages of Crees they offer. Check out nanotuners.com These all sell packages for this purpose and heatsinks, etc. From there you can get an idea of the cost and the work involved. But keep in mind they both sell the high end Crees which cost significantly more but work very well. These FEDY's are a fraction of the cost and people are having success with them.
FLGirl
New member
I mulled on that info, (thx BMB) and came up with something I think looks good and makes sure everybody has the light they need.
I have put alot of thought into this light, I was worried it was going to look tooooooo blue so i scaled back a little on the blue and went with more whites.
Top is 80-88LED Driver
Middle is 24-30LED Driver
Bottom is both
This way saved me a little money, so naturally I prefer it. If it is not enough blue then I also had this one
More blue and 4 of the 24-30LED Driver
what do you guys think?
PS... here is a question for ya. What do you do when one of the LEDs goes out and they are are all epoxied to the frame. Seems like it would be near on impossible to replace it feasibly. Is it possible to use tiny screws to screw in each of these LEDs. I know it is WAY WAY WAY more time consuming, but if one goes out it would be easier to replace, correct? Is it possible? Will it hurt the electrical aspect? Heat conduction?
I have put alot of thought into this light, I was worried it was going to look tooooooo blue so i scaled back a little on the blue and went with more whites.
Top is 80-88LED Driver
Middle is 24-30LED Driver
Bottom is both
This way saved me a little money, so naturally I prefer it. If it is not enough blue then I also had this one
More blue and 4 of the 24-30LED Driver
what do you guys think?
PS... here is a question for ya. What do you do when one of the LEDs goes out and they are are all epoxied to the frame. Seems like it would be near on impossible to replace it feasibly. Is it possible to use tiny screws to screw in each of these LEDs. I know it is WAY WAY WAY more time consuming, but if one goes out it would be easier to replace, correct? Is it possible? Will it hurt the electrical aspect? Heat conduction?
Last edited:
brassmonkyballs
BMB
Yeah....glue them and they are permanent. I always recommend drill and tap and use 4-40 screws...though I'm going to try drilling and self tapping screws shortly. We're discussing this on my home forum now. Yeah I never would recommend gluing myself.....
I mulled on that info, (thx BMB) and came up with something I think looks good and makes sure everybody has the light they need.
I have put alot of thought into this light, I was worried it was going to look tooooooo blue so i scaled back a little on the blue and went with more whites.
Top is 80-88LED Driver
Middle is 24-30LED Driver
Bottom is both
This way saved me a little money, so naturally I prefer it. If it is not enough blue then I also had this one
More blue and 4 of the 24-30LED Driver
what do you guys think?
PS... here is a question for ya. What do you do when one of the LEDs goes out and they are are all epoxied to the frame. Seems like it would be near on impossible to replace it feasibly. Is it possible to use tiny screws to screw in each of these LEDs. I know it is WAY WAY WAY more time consuming, but if one goes out it would be easier to replace, correct? Is it possible? Will it hurt the electrical aspect? Heat conduction?
A flathead screwdriver and a small hammer will remove them. Plus, it's thermal adhesive, so it's going to help with heat transfer to your heat sink (frame).
FLGirl
New member
That's what I was trying to remember. I thought there was a reason for the adhesive.
THX
brassmonkyballs
BMB
Its not the reason for the adhesive but it is a requirement of the adhesive to conduct heat away. The reason for adhesive to hold them down.
If screwing you still need thermal paste...Radio Shack. Hammer and screwdriver to get them off...how do you feel about beating the crap out of your current fixture? Or would you rather use a hex wrench or phillips head to remove them
Great explanation:thumbsup:
But what happens if one LED in a string dies.
Will the other LEDs surfive now 1 string of 5 LEDs is not consuming any amps?
FLGirl
New member
Not according to what he said earlier. The remaining strings would have the extra current ( that is not being consumed by that string ) overpowering the remaining LED strings. Brassmonkeyballs recommended putting a fast blow fuse on each string.
can someone still post a layout so I can get it right. My main question is can I use one long wire for the + pos and have all the strings connected to that one wire or do I run a seperate wire for every string. The same would apply for the - neg
brassmonkyballs
BMB
See my post from last night. In essence though if you lose 1 in a string you lose that string (assuming it fails open as is usually the case). The remaining current gets redirected to the remaining strings. So if we take the example where we used 4.2A to drive 6 strings and each one gets 700ma, then we lose 1 LED in 1 string we now get the 4.2A divided into the remaining 5 strings or 840ma or so. Not the end of the world but significantly above their normal rating and will likely shorten life...which may cause a cascade of another failure in another string, thereby redistributing the current again, etc.
brassmonkyballs
BMB
I stole FLGirls picture and did a quick mod for you...not pretty but gets the point across.
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brassmonkyballs
BMB
Correct...and yes do recommend fuses
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