DZ12488
New Member
I might be new to this forum and I I am hoping there are a lot of high educated and great people out there that can help me a little bit!
I wanted to ...and then I did make a lighted SMV. BUT with delayed malfuctioning of leds after the customer had the unit for a few weeks I was getting discouraged. I am using a total of 24- 20 milliamp, T1 L.E.D. s , there are three-.5x12'' boards in the smv unit, with total of 8 leds on them,Four in series and the other four likewise ,then the series of four are tied together in parallel at hte end of each board to connect the other two boards , and the other two boards with the two sets of four are likewise. Then all three boards are tied together in parallel with one board (which is where the 12.8 VDC is hooked up) having a 1/2 watt 27 ohm resistor. Now! (Problem IS) about a week later or month , it varies, there would be one or two leds sometimes very dim or most times burned out ! I checked the volts across each led and it is about 1.9 VDC and while the board with the series that has burned out led has significant high voltage across leds that are in the same series as the bad one AND the bad one has quite a bit lower voltage across or barely enough to light it WHILE the others in series are significantly higher .
What I would like you guys to do is give me Ideas or a schmatic with what type of resistor you would use and soforth ,,and what would be the pro. way to run this type of setup. I would like or prefer one resistor to run all 24 leds but if that is not proper, then give me some info or tips !! HeyThanks !! Greatly appreciated!
I wanted to ...and then I did make a lighted SMV. BUT with delayed malfuctioning of leds after the customer had the unit for a few weeks I was getting discouraged. I am using a total of 24- 20 milliamp, T1 L.E.D. s , there are three-.5x12'' boards in the smv unit, with total of 8 leds on them,Four in series and the other four likewise ,then the series of four are tied together in parallel at hte end of each board to connect the other two boards , and the other two boards with the two sets of four are likewise. Then all three boards are tied together in parallel with one board (which is where the 12.8 VDC is hooked up) having a 1/2 watt 27 ohm resistor. Now! (Problem IS) about a week later or month , it varies, there would be one or two leds sometimes very dim or most times burned out ! I checked the volts across each led and it is about 1.9 VDC and while the board with the series that has burned out led has significant high voltage across leds that are in the same series as the bad one AND the bad one has quite a bit lower voltage across or barely enough to light it WHILE the others in series are significantly higher .
What I would like you guys to do is give me Ideas or a schmatic with what type of resistor you would use and soforth ,,and what would be the pro. way to run this type of setup. I would like or prefer one resistor to run all 24 leds but if that is not proper, then give me some info or tips !! HeyThanks !! Greatly appreciated!