V series "Tetras"

[stardustsailor]

Lot's of great info here guys thx
as I run differents wavelenghts on different timers, I'm very intersted in those things ...

I also believe in benefits of dimming, that's why I'd like to understand this point:

I've read that pwm dimming produces kind of flickering, (visible on a video recording), but as this 3 in 1 dimming function is just an input command, I used to believe that the 3 types of command should produce the same result, am I wrong ?

or maybe your point was about the powering-on moment, as pwm is not something constant, depending on the driver technology, it could run at full power for the 1st milliseconds, but still voltage dimming shouldn't be concerned ...

There's obviously something that I'm missing ...

I've made an Arduino based device ,not so long ago ,which bears the name " AutosDias" and it's purpose is to dim the LEDS/COBs to imitate the diurnal irradiance ( Dawn=>Noon=>Dusk) .Fully adjustable.It uses PWM dimming.

https://www.rollitup.org/t/the-autos-dias-project.855633/#post-11188892

PWM dimming is the worst option ,regarding the 3in1 dimming function of many branded drivers.
Not so much for plant illumination ,but for human vision illumination ,even at high frequencies of PWM ,
still causes flickering of LEDs / COBs .Not detectable from the human eye ,
but for sure detectable from human nervous system !
That's why I prefer either the "via resistor " or either "via voltage " control of the 3in1 dimming function.

Cheers.

 

[bicit]

I've made an Arduino based device ,not so long ago ,which bears the name " AutosDias" and it's purpose is to dim the LEDS/COBs to imitate the diurnal irradiance ( Dawn=>Noon=>Dusk) .Fully adjustable.It uses PWM dimming.

PWM dimming is the worst option ,regarding the 3in1 dimming function of many branded drivers.
Not such much for plant illumination ,but for human vision illumination ,even at high frequencies of PWM ,
still causes flickering of LEDs / COBs .Not detectable from the human eye ,
but for sure detectable from human nervous system !
That's why I prefer either the "via resistor " or either "via voltage " control of the 3in1 dimming function.

Cheers.

Isn't the PWM dimming just an input signal for the driver to reduce the current output rather than actually flickering the LED's directly?

 

[stardustsailor]

Isn't the PWM dimming just an input signal for the driver to reduce the current output rather than actually flickering the LED's directly?

It switches ON & OFF the driver directly.Thus the LEDS / COBs switch ON & OFF directly.
( " ON & OFF " can also be adjusted to -for example " 10% of power - 90% of power " as well )

That causes direct flickering
(detectable by human vision if PWM frequency is about 200Hz or lower ,specially when the eyes move rapidly sideways).

Cheers.

 

[bicit]

It switches ON & OFF the driver directly.Thus the LEDS / COBs switch ON & OFF directly.
( " ON & OFF " can also be adjusted to -for example " 10% of power - 90% of power " as well )

That causes direct flickering
(detectable by human vision if PWM frequency is about 200Hz or lower ,specially when the eyes move rapidly sideways).

Cheers.

So PWM dimming would not only be bad for humans, but also driver longevity?

I need to go read the data sheet again. I'm woefully ignorant as to how the 3-in-1 dimming feature works.

 

[stardustsailor]

So PWM dimming would not only be bad for humans, but also driver longevity?

I need to go read the data sheet again. I'm woefully ignorant as to how the 3-in-1 dimming feature works.

The basic concept of 3in1 dimming feature is this :

The driver outputs +10 VDC from Dim+ (DIm- being the sink .Caution : Not ground ! )

When Dim+ and DIm - are shorted drivers outputs 0% of it's max output .

(..)
If the control terminals/bus is shorted in any case, the current on the control terminals/bus will be 500 microamps (uA) per driver maximum.
(...)


If left open driver outputs 95-108 % of it's max -nominal- output .

If an external voltage is applied ,then it counteracts the +10 VDC internal voltage and lowers the output.
If a resistor is connected between DIm+ and DIm- ,voltage also drops .
A 10K resistor means 10% of max output while a 100K res is 100% of output ...
When PWM of 10 VDC signal applied ,the rapid switching "ON-OFF" takes place .


More info at the pdfs at the zip file uploaded here.

 

[Devildenis69]

sds: thx a lot, it's clear now.
I thought that the driver would detect difference between a "pwm signal" (high frequency) and any kind of other signal, considered as "voltage signal" ... that way it would switch between two system of detection ...

so as I understand it, it's a simple voltage dimming, that would even work with only a 10vdc on Dim-, Dim+ is here to simulate this input for the resistance dimming ...

p87 in your documentation, there's a solution to delay several drivers, seems quiet simple, even if I don't get the point of the x relay ...

 

[churchhaze]

If the 10V pulse width modulated input goes through a low pass filter, it should not cause the lamp to flicker, right?

 

[stardustsailor]

sds: thx a lot, it's clear now.
I thought that the driver would detect difference between a "pwm signal" (high frequency) and any kind of other signal, considered as "voltage signal" ... that way it would switch between two system of detection ...

so as I understand it, it's a simple voltage dimming, that would even work with only a 10vdc on Dim-, Dim+ is here to simulate this input for the resistance dimming ...

p87 in your documentation, there's a solution to delay several drivers, seems quiet simple, even if I don't get the point of the x relay ...

Yes,this is an inrush current delay.
I'm not sure if it works with solid state relays,as they are much faster in their tripping action than mechanical relays.
I guess the x relay is put there for further delay ,although myself also i can not quite understand why is there .
Still that circuit is not adjustable regarding the actual time delay between the drivers switching ON.
In fact ,the drivers will be switching ON ,seemingly at the same time.The induced delay is so small ,to only
serve it's purpose of suppressing the accumulated insrush current

BTW : Never switch ON & OFF rapidly ,your LED / COB grow lights .

(...) 2.3 Inrush Current
When AC is initially powered ON, a peak current is required to charge the empty bulk
capacitor. This momentary peak is also called the inrush current.
The magnitude of the inrush current varies according to the type of current limiting
circuit used. S.P.S. commonly uses a thermistor to limit inrush current. The high
resistance of the thermistor limits inrush current at cold start of S.P.S.; the low
resistance of the thermistor reduces power consumption after power-on. Thus, in order
not to accumulate inrush current do not turn the power supply ON and OFF rapidly.
Generally, after turning-off, a delay of few seconds before turning-on is suggested.
Compared to the input current in steady state, the inrush current could be several to
tens of times higher. Be aware that application with multiple S.P.S. leads to accumulate
inrush current. In this case, the ability of input wiring, external fuses, and switches to
withstand transient current should be taken into consideration. (...)


Cheers.


PS :
When the V series Tetras is plugged at mains ,
usually the plug is sparking severely while is being inserted in the mains wall socket.
That's something that needs to be fixed.

 

[stardustsailor]

If the 10V pulse width modulated input goes through a low pass filter, it should not cause the lamp to flicker, right?

I'm not sure.
But I think a LOW-pass filter will distort the square wave ,severely ,thus alternating the dimming rate and the PWM duty cycle .
Maybe then flickering is not an issue anymore ,but rather "pulsing " becomes one ...
Guod ,probably knows better ...


Cheers.

 

[Devildenis69]

I pointed out this circuit as an idea, of course some timers have to be put between the "coil" and the "switch", sorry english isn't my native, don't know technical terms ...

churchaze: PWM throught a RC filter, would give you the middle value, seems good, the point here is to reduce the ripple ...

 

[churchhaze]

I pointed out this circuit as an idea, of course some timers have to be put between the "coil" and the "switch", sorry english isn't my native, don't know technical terms ...

churchaze: PWM throught a RC filter, would give you the middle value, seems good, the point here is to reduce the ripple ...

Right, as long as the sampling frequency reading the output signal is significantly lower than the PWM frequency (Edited out for stoned bullshitness! yellow is stoned rambling), You will be able to "integrate" the pwm signal using a low pass filter. (edited)

http://en.wikipedia.org/wiki/Integrator#In_signal_processing_circuits

If you use a duty cycle of 90%, the output will be 0.9 continuous, with ripple depending on the cutoff value of the filter used.

 

[Devildenis69]

Shannon theorem

 

[stardustsailor]

Right, as long as the sampling frequency reading the output signal is significantly lower than the PWM frequency, you will be able to "integrate" the pwm signal using a low pass filter.

http://en.wikipedia.org/wiki/Integrator#In_signal_processing_circuits

If you use a duty cycle of 90%, the output will be 0.9 continuous, with ripple depending on the cutoff value of the filter used.

Then the PWM frequency has to be significally higher than 100 kHz ...
(At least for most Meanwell drivers ,featuring the 3in1 dimming feature )

 

[churchhaze]

Then the PWM frequency has to be significally higher than 100 kHz ...
(At least for most Meanwell drivers ,featuring the 3in1 dimming feature )

Hold on, I'm trying to understand what I wrote now... lol. I think aquarius is right about the weed! bah

 

[Devildenis69]

this one could help
http://ww1.microchip.com/downloads/en/AppNotes/00538c.pdf

 

[AquariusPanta]

Hold on, I'm trying to understand what I wrote now... lol. I think aquarius is right about the weed! bah

Now what did I say about the weed? lol

 

[churchhaze]

Now what did I say about the weed? lol

It makes me fucking stupid as hell. Recently, I've been getting more slow/depressed than usual and not wanting to do anything productive. I've been smoking for over a decade without breaks. Wake up, smoke... smoke smoke... sleep. I do think I'd be better off without it..

I guess some people really do react differently.

 

[AquariusPanta]

It makes me fucking stupid as hell. Recently, I've been getting more slow/depressed than usual and not wanting to do anything productive. I've been smoking for over a decade without breaks. Wake up, smoke... smoke smoke... sleep. I do think I'd be better off without it..

I guess some people really do react differently.

Moderation is the key factor, my dear friend, in how this particular substance affects people (generalization).

The problem for me, years ago, was that I didn't know what moderation meant. I was young and it's only been since those days that I've learnt myself (I've been watching trailer park boys lately) what moderation is, and not just with marijuana but with everything that has the potential to make me less of a being (less productive for you whiners out there).

Some may say that my perception of what is more and less of a man is skewed by the world I grow up in but I still have to live out my life, until the day comes that my soul is released back into nature. Sounds like something a hippie would say, right?

That being said, I'm not comfortable with where my life has been and I want to make more of it and I KNOW smoking or consuming cannabis isn't going to help because it is too good of a drug. It will simply persuade me that everything is ok, temporarily.

So who knows, maybe when I reach that comfort zone, I'll come back to the marijuana flowers and come closer with nature, like I've done in the past.

PM me anytime Churchy, I'm always here for you buddy.

 

[Abiqua]

I find that drinking sugar makes me feel dumber and more lethargic than anything else....I haven't had alcohol or soda going on 5 years now....

 

[stardustsailor]

Moderation is the key factor, my dear friend, in how this particular substance affects people (generalization).

The problem for me, years ago, was that I didn't know what moderation meant. I was young and it's only been since those days that I've learnt myself (I've been watching trailer park boys lately) what moderation is, and not just with marijuana but with everything that has the potential to make me less of a being (less productive for you whiners out there).

Some may say that my perception of what is more and less of a man is skewed by the world I grow up in but I still have to live out my life, until the day comes that my soul is released back into nature. Sounds like something a hippie would say, right?

That being said, I'm not comfortable with where my life has been and I want to make more of it and I KNOW smoking or consuming cannabis isn't going to help because it is too good of a drug. It will simply persuade me that everything is ok, temporarily.

So who knows, maybe when I reach that comfort zone, I'll come back to the marijuana flowers and come closer with nature, like I've done in the past.

PM me anytime Churchy, I'm always here for you buddy.

That's about the same thing I've been yelling for years now...

"Say NO to Marijuana...."
......
" There's just not enough for everybody ! "






Cheers