sandiegoman
New Member
I have a great graphic eq / spectrum analyzer that I am trying to reduce to a 5 x 5 pattern and putting the LEDs on 3' leads.
So I need to remove 3 bands, and 1 led from each column. I don't have a very good schematic, I could not find one online, but one did come with the kit I ordered off of Ebay.
I would like to change all the 3mm LEDs to 8mm Straw Hat Wide Angle White LED - Ultra Bright LEDs using 100-120ma and 3.2 - 3.6v.
I can't believe it, but they actually light up dimly when I swapped 1 row of them out, I would just like for them to have the max brightness.
I have attached the schematic and parts list, any help would be greatly appreciated.
I think what might actually be driving the LEDs is the CD4028BF. That seems to have plenty of power, but I am not 100% sure that is the role of that IC. It looks like the lm3915 is switching the negative on and off and the cd4028BF is providing the + voltage. There is a 10k resistor between each of the pins and a bc337 transistor:
Collector-Emitter Volt (Vceo): 45V
Collector Current (Ic): 0.8A
hfe: 100-250 @ 100mA
Power Dissipation (Ptot): 625mW
Current-Gain-Bandwidth (ftotal): 210MHz
Type: NPN
which then runs to the LED columns.
I am not sure if that will help. It seems to me the problem is with the transistor. I ran a jumper on the 10k resistor that was between the transistor and the LED columns and that actually dropped the brightness so I didn't think that was the problem.
I found this article, which led me to this forum: http://www.talkingelectronics.com/projects/SpotMistakes/SpotMistakesP6.html
The 2nd project looks like what I am looking for, but the solution was not provided. It uses the same transistor as I am currently using, but since there is a problem with the design, I wasn't sure how to fix it on my end to power my stronger LEDs as well.
Any help would be greatly appreciated! Thanks!
Bryan
So I need to remove 3 bands, and 1 led from each column. I don't have a very good schematic, I could not find one online, but one did come with the kit I ordered off of Ebay.
I would like to change all the 3mm LEDs to 8mm Straw Hat Wide Angle White LED - Ultra Bright LEDs using 100-120ma and 3.2 - 3.6v.
I can't believe it, but they actually light up dimly when I swapped 1 row of them out, I would just like for them to have the max brightness.
I have attached the schematic and parts list, any help would be greatly appreciated.
I think what might actually be driving the LEDs is the CD4028BF. That seems to have plenty of power, but I am not 100% sure that is the role of that IC. It looks like the lm3915 is switching the negative on and off and the cd4028BF is providing the + voltage. There is a 10k resistor between each of the pins and a bc337 transistor:
Collector-Emitter Volt (Vceo): 45V
Collector Current (Ic): 0.8A
hfe: 100-250 @ 100mA
Power Dissipation (Ptot): 625mW
Current-Gain-Bandwidth (ftotal): 210MHz
Type: NPN
which then runs to the LED columns.
I am not sure if that will help. It seems to me the problem is with the transistor. I ran a jumper on the 10k resistor that was between the transistor and the LED columns and that actually dropped the brightness so I didn't think that was the problem.
I found this article, which led me to this forum: http://www.talkingelectronics.com/projects/SpotMistakes/SpotMistakesP6.html
The 2nd project looks like what I am looking for, but the solution was not provided. It uses the same transistor as I am currently using, but since there is a problem with the design, I wasn't sure how to fix it on my end to power my stronger LEDs as well.
Any help would be greatly appreciated! Thanks!
Bryan