Sorry again, you' re a really kind and patient person and i do not want to impose on that.
I was convinced that these bridgelux strips were 12V each, this is the reason of my question that made confusion.
I'm not an electronics expert, absolutely agree but as I told you I already built my lamp with 5pcs of citi1212with 12V CPU fans heatsink and potentiometer on HLG-240H-C1400B and it works really well without problems...was not easy for me to understand electronics rule but after some studies i got it.
I learned as at different amperage COBs need more or less volts than nominal datasheet, the same with temperature...so with citizen calculator i make the project and putting a potentiometer with switch i exploited the driver "open circuit" gain a few extra volts i needed (a little bit more than mominal max 179V output)
I'm tellig you that just because you know i can manage an elementary cablage if i understand the elementary theory at the base of it.
I cheked by a "killAwatt" and lamp gave me 250W and i make a full grow cycle without light issues.
As I told you I just like to understand why do you recommend to wire in series(constant current mode) instead of in parallel(costant voltage)..
Parallel would be safer thanx to work at ish 20V of 5 stripes direct current instead of 100V of direct current for 5 stripes wire in series... isn't it?
As i wrote before i know that with cobs the problem of a paralell wiring was concerned with Imax if one cob fail but whit those stripes you told me parallel wire (or mix of both)could be done without pain.
I never see a CV driver in my life, and watching pictures I can not understand why does it have(in the A version) two pots on the driver surface instead of just one to adjust Ampere...maybe because it has both tension and current adjustable(that's is why you say CC/CV driver by any chance?)
It's difficult for me understand toutorial also because of my rubbish european english so I really hope you and the other users could still be patient and help me to make this little project.
Thank you very much for your attenction!
You understand it quite good.
The reason is called "thermal runaways". It's really easy to understand.
At first, these strips are like COB's designed to work with constant current. So the priciples are the same for COB's and strips.
A CC driver gives out a constant current but it's voltage is variable in a certain range(50-100%).
A CV/CC driver gives out constant voltage(allways 100% ±3%) and is "trying" to apply as much current thru the circuit as possible, again in a certain range(driver max.+poti setting).
To drive COB's or strips with a CV/CC driver the circuit needs more planning because it must fit in the small voltage range these drivers gives out(most MW CV driver is ±3v) "and" in case one strip(or COB) fail the rest must be capable to work with the additional current.
BUT!
Most LED's have a slightly different voltage(and resistance) and if you drive them in parallel you get an uneven current flow. Most of the time it's only a few watts, which means it's not visible to the naked eye, but it's of course measurable. In a worst case scenario when the strips run at their limits and gets really hot the differences adds up and the strip with the lowest resistance goes into thermal runways and fails because of too much current flow.
As we know, the rest of the strips must can take the additional current and if there are still differences the next strip gets hotter and burn out and so on.
God thanks, these strips have a pretty good(small) voltage range, I've tested a few F-Series strips and they all fall within a ±0,2v range.(pulsed@ambient temps)
The strips are also much easier to work with because they have a much lower thermal resistance and need much less cooling effort. This makes them even more resistant against thermal runaways.
With CC drivers and a series circuit the current for each individual LED is the same and each LED takes the voltage they need, one a bit more the other a bit less, but all run stable with the same current.
No thermal runaways possible in a CC circuit.
This is the reason every professional engeneer will recommend you to use CC with LED's except they are specially made for CV operation (additional resistors, eg. like 12/24v flex-Strips).