Dimmers - new user help

[gcodori]

Hello everyone - just registered today.

I am new to LED lighting but I'm a handy DIY person so I'm not afraid of putting together a light system based on the 2x2 system using the B-lux gen2 wired in series (per the diagram).

The system calls for a rheostat/pot to be used as a dimmer to lower the light and voltage of the system.

Can anyone explain to me why the dimmer is needed? Isn't raising and lowering the height from the plants typical method of lowering the heat/light available to the plant? What am I missing?

If the dimmer is to limit the power of the system - why isn't the system designed at the correct voltage to begin with?

Is the pot optional? Can I just put the lights on a timer at the correct distance from the plant and be no worse for wear?

What are some situations during a grow where you would utilize a dimmer (other than lowering the shock when you move from grow to flower)?

Sorry for all the newb questions, but a search of the forums have plenty of posts about putting the dimmers in or how to wire them but not much on WHY you need them in the first place.

Thanks!

[Professor Xavier]

Hello everyone - just registered today.

I am new to LED lighting but I'm a handy DIY person so I'm not afraid of putting together a light system based on the 2x2 system using the B-lux gen2 wired in series (per the diagram).

The system calls for a rheostat/pot to be used as a dimmer to lower the light and voltage of the system.

Can anyone explain to me why the dimmer is needed? Isn't raising and lowering the height from the plants typical method of lowering the heat/light available to the plant? What am I missing?

If the dimmer is to limit the power of the system - why isn't the system designed at the correct voltage to begin with?

Is the pot optional? Can I just put the lights on a timer at the correct distance from the plant and be no worse for wear?

What are some situations during a grow where you would utilize a dimmer (other than lowering the shock when you move from grow to flower)?

Sorry for all the newb questions, but a search of the forums have plenty of posts about putting the dimmers in or how to wire them but not much on WHY you need them in the first place.

Thanks!

Hello!
Yes you can adjust heights but a POT can POTentially give you 3 things:
1) BETTER control of light output. Height changes also affect the footprint of your light, having height AND dimming allows you to optimize your canopy light distribution.
2) Power saving. Plants don't always need full wattage on them during their life cycle. By dimming, you may be able to save money as opposed to running at 100% all the time.
3)If you have dimming on lights with different spectra, you can modify your overall spectrum by changing intensities between the lights.
Depending on the wattage it's controlling and your electricity prices, a dimmer can pay for itself within a few months.
There are also some interesting wifi controlled options available out there to remotely control your lighting and set up digital timers for you. I believe there's a chap on the Control subforum on here making an open source control program and there are commercial units like Bluefin on Raplidled.com you can look at.

[sdfoster22]

Yes, seedlings and young plants doesn't really need. The full output of the light. I think dimming a knob is easier than raising lowering lights. Of course you can run full output and raise or lower the lights as needed.

[J.R.R.Toking]

Hi, and welcome to the forum! It's a good one.

To expound on the Professor's number 2 point, these LEDs run more efficiently when powered at @ 75% of maximum, so the general consensus is that it's better to have more strips running at 75% rather than fewer strips at 100%, to hit the intensity needed for successful flowering. It saves electricity, and cuts down on heat. The longevity of the LEDs are increased by running them easier as well.

Another HUGE benefit of having a dimmer is being able to dim the lights while working within your flowering area. These LEDs are EXTREMELY bright, and if you have no dimmer, you'll probably need supplemental lighting to use only when attending your plants (because you'll have to keep the LEDs off, or use a freaking welder's mask).

You said you're new, so maybe you haven't yet watched some of LEDG's videos. They are ALL very good at explaining any issues and developing strategies for your best lighting system. Also, you do know that there are drivers that have integrated POTs, right? These still might not be the best solution, though, as the onboard POTs can only dim the lights to 50%, which is still WAY to bright to work in the flowering area.
http://ledgardener.com/diy-guides/

GL, and again welcome to the forum!

[gcodori]

Hi, and welcome to the forum! It's a good one.

...Another HUGE benefit of having a dimmer is being able to dim the lights while working within your flowering area. These LEDs are EXTREMELY bright, and if you have no dimmer, you'll probably need supplemental lighting to use only when attending your plants (because you'll have to keep the LEDs off, or use a freaking welder's mask)...

I had not thought of the lights during maintenance. I had just planned out what time of day I'd most likely tend to my plants and schedule the light cycle to be "on" during that time so I could simply turn off the light and have the tent open without having light enter the tent during a dark hour.

The perfectionist in me felt it somewhat odd to design a lighting system with a larger power supply and then simply run it at a lower level. I would have thought simply picking a more appropriate supply would be better. Your suggestion make a good deal of sense - it's just different from the old way of growing where the lights have either on or off positions.

Thanks for the encouragement. I'll have to find some resources on light intensity during my plant's life.

[gcodori]

(((SNIP)))

Hello!
Yes you can adjust heights but a POT can POTentially give you 3 things:
1) BETTER control of light output. Height changes also affect the footprint of your light, having height AND dimming allows you to optimize your canopy light distribution.
2) Power saving. Plants don't always need full wattage on them during their life cycle. By dimming, you may be able to save money as opposed to running at 100% all the time.
3)If you have dimming on lights with different spectra, you can modify your overall spectrum by changing intensities between the lights.
Depending on the wattage it's controlling and your electricity prices, a dimmer can pay for itself within a few months.
There are also some interesting wifi controlled options available out there to remotely control your lighting and set up digital timers for you. I believe there's a chap on the Control subforum on here making an open source control program and there are commercial units like Bluefin on Raplidled.com you can look at.

Wow, that was super informative! These are all things that didn't even register with me. I like the idea of not losing the footprint that raising causes. My whole reason for going the DIY route was to get a larger footprint.

I also like the idea of being able to dim different spectrum. I was just planning of picking up 3500K as a compromise between growth and flower. If I dim one of the spectrum does that cut down on the total power? if I make a 100w system and turn down one color to 0%, then the rest of the system is at 50w (or less in order to be efficient).

So many new ideas - I'll need to keep reading all of the neat ideas I've been following here...

[unkle_psycho]

(((SNIP)))

Hello!
Yes you can adjust heights but a POT can POTentially give you 3 things:
1) BETTER control of light output. Height changes also affect the footprint of your light, having height AND dimming allows you to optimize your canopy light distribution.
2) Power saving. Plants don't always need full wattage on them during their life cycle. By dimming, you may be able to save money as opposed to running at 100% all the time.
3)If you have dimming on lights with different spectra, you can modify your overall spectrum by changing intensities between the lights.
Depending on the wattage it's controlling and your electricity prices, a dimmer can pay for itself within a few months.
There are also some interesting wifi controlled options available out there to remotely control your lighting and set up digital timers for you. I believe there's a chap on the Control subforum on here making an open source control program and there are commercial units like Bluefin on Raplidled.com you can look at.

Wow, that was super informative! These are all things that didn't even register with me. I like the idea of not losing the footprint that raising causes. My whole reason for going the DIY route was to get a larger footprint.

I also like the idea of being able to dim different spectrum. I was just planning of picking up 3500K as a compromise between growth and flower. If I dim one of the spectrum does that cut down on the total power? if I make a 100w system and turn down one color to 0%, then the rest of the system is at 50w (or less in order to be efficient).

So many new ideas - I'll need to keep reading all of the neat ideas I've been following here...

When I started planning my light, I was thinking in terms of HPS, so even after realizing I want to use side-lighting, I was still looking at 600w drivers.
At some point I realized the benefit of getting your lights 50% closer is 400%, while the benefit of moving from HPS to led is perhaps 40% at best.

Finally with the help of LEDG forum members I settled for a setup that felt pretty weired in the beginning. Instead of a 4x4 light, I'm making 2 2x4 lights. Now I'm working on the first one. It has 6 75w drivers driving 9 2foot vestas. Each strip has 96 2700k and 96 5000k diodes on their own channels, so each driver feeds a single channel of 3 drivers.

This gives pretty crazy flexibility, I can activate one driver for early veg, so only 3 5000k channels light up, covering about 2x1.5 foot. I can also light up any other combo in series of 3strips, only covering the area I need.
With dimming I can achieve even more control over light output, and I get control over the spectrum between 2700k and 5000k. I can theoretically tune spectrum individually for each plant too, although there would usually be a little spill over to neighboring plants.

I think one more benefit of having 10 75w drivers is, that as the tech advances year by year, I can test new modules without going all in.

The wasteful aspect of what I'm building is that 6x75w is 450w, which is almost double the wattage I'm aiming for in 2x4. The slack was necessary to have the full range of color temperature tuning. I guess my light has the overkill option too, but all the power I add after 225w is pushing me towards 3750k, which would be the temperature of both strips at equal blast

[Aolelon]

Youll want a dimmer, trust me. There are countless examples, Such have been posted here, But its also better to have one and not need it.. Than need one and not have it. I make adjustments constantly with the height and dimmer.