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Also: I am not aware of any op-amp that can output 375mA.
Would this circuit and these components do the job for me??
The LED lamp (RL) has a max current of about 375 mA (12 V and 4,5W).The arduino has a max output current of 40 mA.
The calculations that I base my choice of transistor on:hFE(min) > 5*(IC/IArd.max) = 5*(375/40) = 46.875 about 50==> hFE(min) > 50RB = (VIC * hFE)/(5*IC) = 60/(375*10-3) = 160 ohmI'm a bit unsure about the hFE value because the datasheet displayed many values....
[...] it says on the site of order that it can't be dimmed..... Not sure why. It's a lamp that consists of 90 individual LED's, they seem to be controlled by an internal chip and I suspect that this chip triggers on a certain voltage to turn the LED's fully on. How it will respond to a PWM signal is not known to me.
I think I will buy another lamp from ebay: