My attempt at a professional style DIY light - Page 5 - The Planted Tank Forum
 7Likes
Reply
 
LinkBack Thread Tools Display Modes
post #61 of 81 (permalink) Old 03-10-2018, 09:14 PM Thread Starter
Planted Member
 
MrMan's Avatar
 
PTrader: (0/0%)
Join Date: Dec 2014
Location: Vancouver
Posts: 224
So I decided to pick up a Seneye reef this week so I could check what PAR this light was putting out. Glad I had it turned down since at full brightness it was 160 at the bottom (24" from the light).



I turned down the FreshFish COBs to 40% (although they arn't even running at the full 1A) and warm white to 15% for ~60PAR on the bottom. At the surface level right under the lights is still 150 but the most any of the higher plants are getting is 80 now...



To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by MrMan; 03-10-2018 at 09:16 PM. Reason: Fixed image links
MrMan is offline  
Sponsored Links
Advertisement
 
post #62 of 81 (permalink) Old 03-11-2018, 04:35 PM
Planted Tank Enthusiast
 
PTrader: (1/100%)
Join Date: Nov 2015
Location: Kalamazoo Mi
Posts: 504
very nice, wish someone in my area had a par meter to borrow, curious what my freshfish is doing par wise mine is the bigger 1211 chip running at 1200ma, and i'm using a vero10 for my warm chip running at 300ma. i notice quite a bit of algea growth when running full out lately so dialed i back to 50% for both.

how are you liking the freshfish led over your tank?
Kampo is offline  
post #63 of 81 (permalink) Old 03-11-2018, 09:03 PM Thread Starter
Planted Member
 
MrMan's Avatar
 
PTrader: (0/0%)
Join Date: Dec 2014
Location: Vancouver
Posts: 224
Quote:
Originally Posted by Kampo View Post
very nice, wish someone in my area had a par meter to borrow, curious what my freshfish is doing par wise mine is the bigger 1211 chip running at 1200ma, and i'm using a vero10 for my warm chip running at 300ma. i notice quite a bit of algea growth when running full out lately so dialed i back to 50% for both.

how are you liking the freshfish led over your tank?
I couldn't find anyone locally with one to borrow but wanted to know since the light seemed super bright. I still like the fresh fish light but the warm white I'm not as crazy about so I ordered a few 660 leds last week.

Sent from my Nexus 6P using Tapatalk


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
MrMan is offline  
 
post #64 of 81 (permalink) Old 03-13-2018, 09:50 PM
Algae Grower
 
PTrader: (0/0%)
Join Date: Oct 2017
Location: Aizawl
Posts: 22
@MrMan a question or two on your lm3414 driver, i assumed you are using 10k trim pot on iadj, my question is what is the value of resistor you use on FS, is it like in the datasheet? I am quite confuse because the datasheet does not use a trim pot and i am not very cleared on the relation of Iadj and FS.
zlpa chawngthu is offline  
post #65 of 81 (permalink) Old 03-13-2018, 10:09 PM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: WI
Posts: 12,215
Actually it does, sort of variable resistor (thermistor) = trimpot



At least as I understand it..


Just food for thought.

Quote:
Analog Dimming Control
The IADJ pin can be used as an analog dimming signal input. As the average output current of the LM3414
depends on the current being drawn from the IADJ pin, thus the LED current can be increased or decreased by
applying external bias current to the IADJ pin. The simplified circuit diagram for facilitating analog dimming is as
shown in Figure 17. The minimum LED current for analog dimming is 100 mA and the converter must remain in
continuous conduction mode (CCM). The switching frequency and inductor value must be sized accordingly.

Figure 18 shows an example circuit for analog dimming control using simple external biasing circuitry with a
variable resistor.
I assume you need R1ADJ so as to not go below a minimum value..
Extended circuitry to tweak the IADJ circuit..

"A man with a watch knows what time it is. A man with two watches is never sure"

Last edited by jeffkrol; 03-13-2018 at 10:20 PM. Reason: edit
jeffkrol is offline  
post #66 of 81 (permalink) Old 03-13-2018, 11:28 PM Thread Starter
Planted Member
 
MrMan's Avatar
 
PTrader: (0/0%)
Join Date: Dec 2014
Location: Vancouver
Posts: 224
Quote:
Originally Posted by zlpa chawngthu View Post
@MrMan a question or two on your lm3414 driver, i assumed you are using 10k trim pot on iadj, my question is what is the value of resistor you use on FS, is it like in the datasheet? I am quite confuse because the datasheet does not use a trim pot and i am not very cleared on the relation of Iadj and FS.
No important relationship between Iadj and FS. Iadj adjusts the output current of the driver at 100% PWM, section 8.1.2 of the datasheet has this table:

IOUT (mA) RIADJ (kΩ)
350 8.93
500 6.25
700 4.46
1000 3.13

So I used a 3K09 in series with a 5K pot which allows ~400mA to 1A output current. FS is the switching frequency of the driver, higher frequency means a smaller inductor but the minimum output voltage also rises. IE, with 48V in and 500kHz switching frequency (40K Rfs) the minimum output voltage is 9.6V. So you can't run a single LED on a channel. If you raise the frequency to 1MHz the minimum voltage is 19.2V, or 250kHz is 4.8V. You'd have to calculate the inductor value for any given frequency based on how much ripple current you want.

I would suggest sticking with 40K for Rfs and 47uH as shown in their diagram unless you want to optimize for a very specific build.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
MrMan is offline  
post #67 of 81 (permalink) Old 03-13-2018, 11:42 PM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: WI
Posts: 12,215
Quote:
So I used a 3K09 in series with a 5K pot which allows ~400mA to 1A output current.
so in english you put this at R1ADJ..
No need for the transistor circuit....?????

Why do they recommend it???

Sorry learning here..

"A man with a watch knows what time it is. A man with two watches is never sure"
jeffkrol is offline  
post #68 of 81 (permalink) Old 03-14-2018, 12:02 AM Thread Starter
Planted Member
 
MrMan's Avatar
 
PTrader: (0/0%)
Join Date: Dec 2014
Location: Vancouver
Posts: 224
Quote:
Originally Posted by jeffkrol View Post
so in english you put this at R1ADJ..
Correct.

Quote:
Originally Posted by jeffkrol View Post
Why do they recommend it???

Sorry learning here..
I don't think they recommend it, just give it as an option. Here is the relevent text from them regarding that circuit:

Quote:
This feature is exceptionally useful for the applications with analog dimming control signals such as those from
analog temperature sensors and ambient light sensors.
Figure 18 shows an example circuit for analog dimming control using simple external biasing circuitry with a
variable resistor
So you could use this to automatically reduce the output current if your heatsink/driver get too hot. Useful feature but in our case I don't think we'd want our lights getting dimmer in the hot summer months and brighter in the cold winter months. So I used the more basic example of a fixed resistor on Iadj which changes the current draw from the pin and therefore the output current.

Did that help? (check figure 22 for standard usage)


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

Last edited by MrMan; 03-14-2018 at 12:05 AM. Reason: edit
MrMan is offline  
post #69 of 81 (permalink) Old 03-14-2018, 01:07 AM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: WI
Posts: 12,215


Ok well let me try to show it "as I see it"

you added resistor and pot in green circle..
Both diagrams on the spec sheet show it at position red circle (just pot or varistor)

The transistor circuit does "stuff" left of blue line to affect input to IADJ...
Both fig 18 and 19 use a variation of the transistor circuit..
If someone asked me to guess as to why position red is preferred over position green I'd guess for stability..or a more linear response..

Not that I doubt either works just fine..

both the temp sense circuit and "manual" dimming use it..

BTW NO idea if blue line is drawn in the correct spot...
I like your way, simple and effective btw..


"A man with a watch knows what time it is. A man with two watches is never sure"

Last edited by jeffkrol; 03-14-2018 at 01:33 AM. Reason: edit
jeffkrol is offline  
post #70 of 81 (permalink) Old 03-14-2018, 05:16 PM Thread Starter
Planted Member
 
MrMan's Avatar
 
PTrader: (0/0%)
Join Date: Dec 2014
Location: Vancouver
Posts: 224
Quote:
Originally Posted by jeffkrol View Post


Ok well let me try to show it "as I see it"

you added resistor and pot in green circle..
Both diagrams on the spec sheet show it at position red circle (just pot or varistor)

The transistor circuit does "stuff" left of blue line to affect input to IADJ...
Both fig 18 and 19 use a variation of the transistor circuit..
If someone asked me to guess as to why position red is preferred over position green I'd guess for stability..or a more linear response..

Not that I doubt either works just fine..

both the temp sense circuit and "manual" dimming use it..

BTW NO idea if blue line is drawn in the correct spot...
I like your way, simple and effective btw..

Think of it more like this, I used a resistor/pot to set Iadj so I can have a range of output current. But in a fixed production lighting design that would be a single resistor to get a fixed current (let's say 1A). That's all that's needed to use the LM3414.

IF you wanted analog dimming you would add the transistor design (note that this is separate from PWM dimming). With this design you have a fixed Riadj to set a fixed output current and use a analog sensor (not a pot) in the transistor circuit to dim the output current under certain conditions like a hot heatsink or dim ambient light.

So you would never use a potentiometer in the transistor circuit, only on Riadj if you wanted to be able to change the output current easily in prototyping (or in this case hobby use).

Quote:
BTW NO idea if blue line is drawn in the correct spot...
Yes that is in the correct spot, you can remove the stuff in the blue circuit entirely with no issues.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
MrMan is offline  
post #71 of 81 (permalink) Old 03-14-2018, 05:57 PM
Planted Tank Guru
 
PTrader: (0/0%)
Join Date: Jun 2013
Location: WI
Posts: 12,215
analog dimming adjusts current...
Same difference...
Analog dim affects the same circuit as a resistor/pot would..

Sorry, not trying to be difficult but see no reason you can't analog dim and PWM at the same time..

Seems more a matter of sematics..

your method works, and as I said seems sound..
Thanks for the info.

"A man with a watch knows what time it is. A man with two watches is never sure"
jeffkrol is offline  
post #72 of 81 (permalink) Old 03-14-2018, 06:13 PM Thread Starter
Planted Member
 
MrMan's Avatar
 
PTrader: (0/0%)
Join Date: Dec 2014
Location: Vancouver
Posts: 224
Quote:
Originally Posted by jeffkrol View Post
analog dimming adjusts current...
Same difference...
Analog dim affects the same circuit as a resistor/pot would..

Sorry, not trying to be difficult but see no reason you can't analog dim and PWM at the same time..

Seems more a matter of sematics..

your method works, and as I said seems sound..
Thanks for the info.
I wasn't trying to say you can't do both. Just that you wouldn't use the transistor circuit for manual analog dimming. If you want a pot for analog dimming you'd put it at Riadj like I did. If you wanted automatic (via heat/light) analog dimming you'd use the transistor circuit.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
MrMan is offline  
post #73 of 81 (permalink) Old 03-14-2018, 07:59 PM
Algae Grower
 
PTrader: (0/0%)
Join Date: Oct 2017
Location: Aizawl
Posts: 22
So I used a 3K09 in series with a 5K pot which allows ~400mA to 1A output current. FS is the switching frequency of the driver, higher frequency means a smaller inductor but the minimum output voltage also rises. IE, with 48V in and 500kHz switching frequency (40K Rfs) the minimum output voltage is 9.6V. So you can't run a single LED on a channel. If you raise the frequency to 1MHz the minimum voltage is 19.2V, or 250kHz is 4.8V. You'd have to calculate the inductor value for any given frequency based on how much ripple current you want.

I would suggest sticking with 40K for Rfs and 47uH as shown in their diagram unless you want to optimize for a very specific build.[/QUOTE]

Thanks, 40k and 47uH i had to stick with this so i don't had to order these parts, they are lying around at my parts collection box.
zlpa chawngthu is offline  
post #74 of 81 (permalink) Old 03-17-2018, 01:38 PM
Algae Grower
 
PTrader: (0/0%)
Join Date: Oct 2017
Location: Aizawl
Posts: 22
This design is so neat would you happen to share the schema diagram, just curious of the led driver for i-aqua, don't bother about the wemos etc.
zlpa chawngthu is offline  
post #75 of 81 (permalink) Old 03-19-2018, 04:35 PM Thread Starter
Planted Member
 
MrMan's Avatar
 
PTrader: (0/0%)
Join Date: Dec 2014
Location: Vancouver
Posts: 224
Quote:
Originally Posted by zlpa chawngthu View Post
This design is so neat would you happen to share the schema diagram, just curious of the led driver for i-aqua, don't bother about the wemos etc.
Check out the design example in the datasheet, section 8.2.2. It's got part values and even manufacturer part numbers you could use. Only change to make for adjustable current is using a 5K pot and 3K09 resistor in series from Iadj to gnd.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.


To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
MrMan is offline  
Reply

Tags
None

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the The Planted Tank Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome