Just FYI, I am not an experienced electrical engineer/designer
I am designing a PCB that has several items using varying voltage and current: (supply is 12v DC)
My LED (3up cree high power Luxdrive LED) requires +/-7v @ 450mA
My DVR, Attiny85, LT1215 op amp and electret mic will use 5v (current varies of course but approx 40mA and less)
My board cam will use the 12v supply, so no prob there.
My question is, should I go with two bulky voltage regulators to get the voltage required, then limit current as needed using resistors? (5v & 7v)
I find that limiting 7v @ 450mA burns up (via voltage divider) my 1/4w resistors w/o using the bulky voltage regulator. For a PCB, what is the best approach to get my 7v and 5v supply as well as limiting the 7v to .450A and the 5v to around .04A?
I have looked at voltage and current dividers and the math just doesn't allow me to use 1/4w resistors.
Maybe I need to get BIG resistors? Please help, and thx, and yes, I am willing to pay someone to help
me finalize this (design/consulting). My PCB is designed in Eagle.
Thx in advance
-John
I am designing a PCB that has several items using varying voltage and current: (supply is 12v DC)
My LED (3up cree high power Luxdrive LED) requires +/-7v @ 450mA
My DVR, Attiny85, LT1215 op amp and electret mic will use 5v (current varies of course but approx 40mA and less)
My board cam will use the 12v supply, so no prob there.
My question is, should I go with two bulky voltage regulators to get the voltage required, then limit current as needed using resistors? (5v & 7v)
I find that limiting 7v @ 450mA burns up (via voltage divider) my 1/4w resistors w/o using the bulky voltage regulator. For a PCB, what is the best approach to get my 7v and 5v supply as well as limiting the 7v to .450A and the 5v to around .04A?
I have looked at voltage and current dividers and the math just doesn't allow me to use 1/4w resistors.
Maybe I need to get BIG resistors? Please help, and thx, and yes, I am willing to pay someone to help
me finalize this (design/consulting). My PCB is designed in Eagle.
Thx in advance
-John