So I'm new here and wish I would have found this site back when I was in school Anyways, I do have electronics training, but I've been out of school about 5-6 years and I'm very rusty.
On to my project. Me and a friend, who also has basic electronics knowledge are trying to make a plant growing LED light. We have three sets of LED's that we plan on using and I was originally planning on using some LM317's with the voltage input coming from an old PC SMPS 12V rail.
I have been working on the design, but keep hitting stumbling blocks.
Say we had 5 of each LED to power.
Blue Typ. Vf =3.4V Max current =300mA - 1W output
UV Typ. Vf = 3.4V, Max current =300mA - 1W output
Red Typ. Vf = 2.2V, Max current = 300mA - 1W output
Now onto the "theory" that I think is in my head
What if I set an LM317 to current regulating, and setup 3LED's in series under R1 with the ADJ reference coming from that string only.
Then I take another parallel string with just two LED's in series and adjust the R2 on that line to compensate for the current needed. Would R2 not do it's job to control the current, as LED's are mainly concerned with the current??
I have read the concerns on parallel circuits, but if R2 value is set properly and the current for both strings is even, wouldn't the regulator keep it that way?
Love to hear your thoughts, and thanks ahead of time!
On to my project. Me and a friend, who also has basic electronics knowledge are trying to make a plant growing LED light. We have three sets of LED's that we plan on using and I was originally planning on using some LM317's with the voltage input coming from an old PC SMPS 12V rail.
I have been working on the design, but keep hitting stumbling blocks.
Say we had 5 of each LED to power.
Blue Typ. Vf =3.4V Max current =300mA - 1W output
UV Typ. Vf = 3.4V, Max current =300mA - 1W output
Red Typ. Vf = 2.2V, Max current = 300mA - 1W output
Now onto the "theory" that I think is in my head
What if I set an LM317 to current regulating, and setup 3LED's in series under R1 with the ADJ reference coming from that string only.
Then I take another parallel string with just two LED's in series and adjust the R2 on that line to compensate for the current needed. Would R2 not do it's job to control the current, as LED's are mainly concerned with the current??
I have read the concerns on parallel circuits, but if R2 value is set properly and the current for both strings is even, wouldn't the regulator keep it that way?
Love to hear your thoughts, and thanks ahead of time!