It has taken most of the past week and a late night yesterday but the LEDs are finally up and running.
Last week I received the heat sinks and started assembling the two halves.
Before installing, I labeled all of the in case I fried one and needed to figure out what needed replacing. I used a utility knife blade to spread out the thermal compound on the back of each.
Once everything was screwed down, it took me several more hours to connect all the little wires. Once that was done I checked them all to make sure I had good connections:
The one thing I forgot to do was to do a continuity check from the last LED back to the driver. When I turned on the blues, one of the four strings wouldn't light up. Turned out to be a single LED didn't have a connection between the return terminals. I bypassed that for now and made the other string match but eventually I will replace the bad LED with a new one. Lesson learned.
Because I'm using parallel strings, I incorporated measurement resistors and fuses in each string.
These made life very easy as I can just put the multimeter probes onto the screws for measuring the current through the strings. Also, If i blow a fuse they are easy to replace (I bought extras just in case).
Most of yesterday was spent wiring and mounting all the components onto the back of the hood:
The two drivers on the left are for the blues and the right drivers power the whites and colored strings. Since all the blues come on at the same time, the drivers are on the same power cord. My intention is to have the blues come on first and turn off last so they plug into the Neptune Socket Expansion along with the dimming kit. When I upgrade my controller there will be a controlled power strip in the hood along with a dimming module but for now this should do the job.
Here is a close up view of the center:
While it looks complicated, its just the same thing repeated four times. The output cable from the driver has four wires which connect to the terminal strip. In the middle of the input strip, the blue and white wires from the driver match up to the blue and green wires from the dimming module. Above and below that the V+ and V- wires from the driver connect through the fuses and resistors to the corresponding side of the LEDs. By mounting all this on the back of the hood I can measure the current going through the LEDs just by touching the screws in the terminal strips with the multimeter probes.
When running parallel strings, the strings need to be balanced. To do this, you need to measure the current each string carries but this would require installing the multimeter somewhere in the string which would affect the readings each time. A simple work around is to include a 1ohm resistor in each string. By measuring the voltage drop across this resistor, you get a measure of current due to V=IR since R in this case is 1. I got lucky in that my strings are relatively balanced right from the start and so I didn't need to swap LEDs. Eventually I may have to play with the color string but for now I'm within 50mA at full power on the blues and whites.