okay the parts from digikey arrived !
so I don't want to make any drama or anything but holy sh*t that's a LOT of plastic
Anyways: here is the rundown:
FQD7N10LTMCT-ND - MOSFET N-CH 100V 5.8A DPAK (50)
RNCP1206FTD1R00CT-ND - RES 1 OHM 1% 1/2W 1206 (200)
MCP1501-10E/SN-ND - IC VREF SERIES 0.1% 8SOIC (got 2)
1276-1072-1-ND - CAP CER 2.2UF 25V X7R 1206 (5)
399-C1206C301J5GAC7800CT-ND - CAP CER 300PF 50V C0G/NP0 1206 (5)
other orders:
MCP 4461-103E/ST - digital pot quad channel 256 step (7)
MC 33204 DG - op amp 4 channel SO-14 (15?)
I did try a setup with 1 op-amp, 5v source, 10R resistor and no potentiometer, just some resistors
it did work, kinda?
was very touchy, probably because of beeing on a breadboard and mid air
also the current wasn't right, at all, should have been 300mA was like 100mA, should be 600mA was like 250mA
i assume this is because breadboard + no resistors/caps anywhere
here the the plan:
https://tinyurl.com/2d2zq6m7 - simulation does not work anymore, but will be relevant
basically i would use EasyEDA to make the curcuit and later maybe @OM222O can help with the PCB because you guys know tricks, i don't... or maybe he can do both, that be appreciated, more below
the led grid will be 4x4 and every led has 2 channels
because everything is quad channel (pot, op-amp)
i assume the best is to fit 1 quad potentiometer which will control 8 leds, 2 zones x 2 colors x 2 leds
this would give me current control over 2 leds at a time
if you imagine the grid beeing like this:
11 12 13 14
21 22 23 24
31 32 33 34
41 42 43 44
also every number having W for warm and C or cold
first board would allow me to control current to:
11C + 12C (pair) (one pot, 2op amps, 1 follower)
11W + 12W (pair) (one pot, 2op amps, 1 follower)
13C + 14C (pair) (one pot, 2op amps, 1 follower)
13W + 14W (pair) (one pot, 2op amps, 1 follower)
i could split it from 2 to 1 or expand it from 2 to 4 (basically have 4 zones/rows)
but if i split it, i need more digital pots (i only have 7 i think)
and if i expand it to 4 to would be messier design
or maybe we put the follower and potentiometer on the same board as arduino/raspi ? that would be even better now i think? and 1 board is 4 leds (instead of
, so 11W, 11C, 12W, 12C and takes 2 signals/voltages 0 - 1.024v
I dont know the best way, please let me know what's smartest
anyways, please add/or let me know what and where caps/resistors for stability/stop oscilations from the opamps/followers as well as general stability
the mains (well, 24v) fuse will go in circuit without a board, but if you have ideas what to add on the board, let me know !
i will also need a carrier board for the leds, but that will come later
don't need the full pcb design now, just approx size/plans
currently my next step is getting the heatsinks, however im in a middle on moving 600km
thanks, this wouldn't be possible without your help ! (i will set up github and everything once im mostly done)