After the interesting testing with the Ray Wu 2 pin pigtails that dismayed me with the voltage drop I went on the search for options that didn't cost an arm and a leg.
Now power injection especially at 5v is a fact of life.
One option of course it to just buy the power injection T's already made. Now i don't own any but if they use the same 0.5mm2 cable that is common then they are far from effective.
I have always just hung a Ray Wu 2pin off the pixel string used either 1mm2 or 0.75mm2 to get from the PSU .... hey it worked but certainly no were near as good as it could be.
So with some past/current experience in the RF world where insertion loss for connectors is a big deal I conducted some measurements on 3 IP68 options i have now.
So test scenario was approx 400mm length from PSU to E-Load with a Male/Female connect pair in the middle
Current used to get voltage drop and hence insertion resistance was 10A
So in the ring is top to bottom
A cheap weatherproof automotive connectors that you can squeeze 1mm2 (10A) cable into but i have been using 0.75mm2 as it fits better
A M16 2 pin connector as purchased with pure copper 0.75mm2 conductors, this is the same physical size as the Ray Wu 3pin units also M16 size
a Ray Wu 13.5mm 2Pin connector, This is an old pair with pure copper wire but 0.5mm2. this wire size is normal but i do have thinner wire ones in this range.
Bottom is 400mm of Twin flex 0.75mm pure copper purchased from Bunnings in the past as a control measure.
Yeah i actually had to extend the Auto connector wire a little.
Note the voltage drop numbers are for the pair of connectors as shown in the photo.
My thoughts on the numbers.
cheers
Phil
Now power injection especially at 5v is a fact of life.
One option of course it to just buy the power injection T's already made. Now i don't own any but if they use the same 0.5mm2 cable that is common then they are far from effective.
I have always just hung a Ray Wu 2pin off the pixel string used either 1mm2 or 0.75mm2 to get from the PSU .... hey it worked but certainly no were near as good as it could be.
So with some past/current experience in the RF world where insertion loss for connectors is a big deal I conducted some measurements on 3 IP68 options i have now.
So test scenario was approx 400mm length from PSU to E-Load with a Male/Female connect pair in the middle
Current used to get voltage drop and hence insertion resistance was 10A
So in the ring is top to bottom
A cheap weatherproof automotive connectors that you can squeeze 1mm2 (10A) cable into but i have been using 0.75mm2 as it fits better
A M16 2 pin connector as purchased with pure copper 0.75mm2 conductors, this is the same physical size as the Ray Wu 3pin units also M16 size
a Ray Wu 13.5mm 2Pin connector, This is an old pair with pure copper wire but 0.5mm2. this wire size is normal but i do have thinner wire ones in this range.
Bottom is 400mm of Twin flex 0.75mm pure copper purchased from Bunnings in the past as a control measure.
Yeah i actually had to extend the Auto connector wire a little.
| mOhms Total | vdrop @ 10a | Vdrop @ 5A | |
| Auto 2pin | 41 | 0.41 | 0.21 |
| M16 2 pin | 34 | 0.34 | 0.17 |
| Ray wu 2 pin | 126 | 1.26 | 0.63 |
| 400mm wire | 38 | 0.38 | 0.19 |
Note the voltage drop numbers are for the pair of connectors as shown in the photo.
My thoughts on the numbers.
- The 400mm wire segment sets the baseline for the self terminated option of the Auto connector. The connector adds a few milliOhms and is largely transparent
- The M16 with 0.75mm2 wire actually beats it and has the lowest loss overall.
- The smaller Ray Wu connector with the lower wire size is even for 5A about the peak current for pixel strings is not really suitable if your chasing the lowest loss. Ok in a 12v setup, use as loast resort in 5v
- The Auto connector as above is largely transparent and the extra splice joint may have caused a slight loss.
cheers
Phil
