problem controling a nicrew 50W lamp

bishoptf

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One could design a much better DC voltage source using a L293D or L9110H bridge driver, but using just one transistor this is probably the easiest.

If one needs voltages below 0.8V or more linearity above 9.0V one could modify a few more things (exchange the 2N2222A npn-transistor for an n-channel MOSFET like the 2N7000, can be plugged in the exact same place and wont need the resistor to the PCA9685; as well as using a Shottky diode like a 1N5817 instead of a regular rectifier diode like 1N4001).
LOL, your hurting my head...I will do a diagram and then make some options etc and we can have several diagrams for folks to follow..:)
 

oreo54

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Going back to the very first thread.. Kessil may work w/ 10V PWM but as seen Nicrews have "issues".
Each of the kessil light control requires two 10V PWM
He built a 10V PWM source using the Adafruit Guide
I suspect in a correctly built Nicrew a 0-10V analog signal will work just fine.
Am I correct?

Trick seems to be how "clean" one can build a 5v (3.3V) PWM to 0-10 analog circuit.
 

bishoptf

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Going back to the very first thread.. Kessil may work w/ 10V PWM but as seen Nicrews have "issues".


I suspect in a correctly built Nicrew a 0-10V analog signal will work just fine.
Am I correct?

Trick seems to be how "clean" one can build a 5v (3.3V) PWM to 0-10 analog circuit.
The one that @Sral came up with based on the original Kessil control works just fine from what I can see and it is pretty easy to implement - https://www.reef2reef.com/threads/problem-controling-a-nicrew-50w-lamp.960601/post-10985437

I am going to document that one and there are many options that you could do to make it better but is it really needed or not is another question, I just like to have something easy to implement and easy to follow and works well...im a simpleton...:)
 
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Sral

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Sry ^^
I tried to reproduce this in fritzing, but the Capacitors are horrible to place. Here's my try:
AdafruitGuide_DC_Voltage_schem.png

AdafruitGuide_DC_Voltage_bb.png


Going back to the very first thread.. Kessil may work w/ 10V PWM but as seen Nicrews have "issues".


I suspect in a correctly built Nicrew a 0-10V analog signal will work just fine.
Am I correct?

Trick seems to be how "clean" one can build a 5v (3.3V) PWM to 0-10 analog circuit.
I suspect you are. I guess Kessils are built with both PWM and Analog in mind, to give the customer the most flexibility while using a few parts extra. Nice strategy, it has to be said.

The circuit above is approximately what I suggested as a quick fix to @Tom Bishop which seems to have worked in eliminating the flicker.

The OP-Amp circuit in your link looks pretty good.
I'd personally rather do it using a complementary n-channel and p-channel logic MOSFET IC. kind of like a single L293D channel made with MOSFETs. That way you can easily convert the 3.3V or 5V PWM to 10V PWM and smooth that to DC with a resistor and capacitor. If the timings of the transistors are good this should result in a very nice 0-10V DC.
 
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bishoptf

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Sry ^^
I tried to reproduce this in fritzing, but the Capacitors are horrible to place. Here's my try:
AdafruitGuide_DC_Voltage_schem.png

AdafruitGuide_DC_Voltage_bb.png



I suspect you are. I guess Kessils are built with both PWM and Analog in mind, to give the customer the most flexibility while using a few parts extra. Nice strategy, it has to be said.

The circuit above is approximately what I suggested as a quick fix to @Tom Bishop which seems to have worked in eliminating the flicker.

The OP-Amp circuit in your link looks pretty good.
I'd personally rather do it using a complementary n-channel and p-channel logic MOSFET IC. kind of like a single L293D channel made with MOSFETs. That way you can easily convert the 3.3V or 5V PWM to 10V PWM and smooth that to DC with a resistor and capacitor. If the timings of the transistors are good this should result in a very nice 0-10V DC.
You beat me to it, I think you may want to take another look at that second capacitor at least from me looking at it the diode and resistor are not going to the same spot on the cap. That and the grounds, not the same...
 

theatrus

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Sry ^^
I tried to reproduce this in fritzing, but the Capacitors are horrible to place. Here's my try:
AdafruitGuide_DC_Voltage_schem.png

AdafruitGuide_DC_Voltage_bb.png



I suspect you are. I guess Kessils are built with both PWM and Analog in mind, to give the customer the most flexibility while using a few parts extra. Nice strategy, it has to be said.

The circuit above is approximately what I suggested as a quick fix to @Tom Bishop which seems to have worked in eliminating the flicker.

The OP-Amp circuit in your link looks pretty good.
I'd personally rather do it using a complementary n-channel and p-channel logic MOSFET IC. kind of like a single L293D channel made with MOSFETs. That way you can easily convert the 3.3V or 5V PWM to 10V PWM and smooth that to DC with a resistor and capacitor. If the timings of the transistors are good this should result in a very nice 0-10V DC.

Honestly, just is a worse op-amp then.

The quick filter+output on the Pi-pico was


1674761445672.png



The resistor values were economized for the board loading so it could literally "go to 11", but adjust to suit your needs :)
 

bishoptf

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Honestly, just is a worse op-amp then.

The quick filter+output on the Pi-pico was


1674761445672.png



The resistor values were economized for the board loading so it could literally "go to 11", but adjust to suit your needs :)
But an npn is easier to come by and simpler to implement imho, you electronic whizzes then it makes sense but simple is better for me. I understand the diagram for the most part but I am doing through hole proto board stuff. One question is why on the second pwm2 circuit there is no ground coming from the mcp6h02 like there is in the first one?
 

oreo54

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I'm sorry.. got WAY off base here...
Don't know what I was thinking ..
My gibberish is embarassing

Carry on..
 

theatrus

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But an npn is easier to come by and simpler to implement imho, you electronic whizzes then it makes sense but simple is better for me. I understand the diagram for the most part but I am doing through hole proto board stuff. One question is why on the second pwm2 circuit there is no ground coming from the mcp6h02 like there is in the first one?

MCP6H02 is a dual-opamp single package. There is also an MCP6H04 with 4 op-amps in a single package. This is a pretty common industry standard defacto pinout, including DIP parts available (just not this exact op-amp).

Nothing wrong with a simple single transistor circuit here. There are a ton of reasons why its worse, but none really matter all that much for the intended purpose :)

1674762287230.png
 
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Sral

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You beat me to it, I think you may want to take another look at that second capacitor at least from me looking at it the diode and resistor are not going to the same spot on the cap. That and the grounds, not the same...
Ooops, you are right. I also forgot 2 GND connections XD Here's the updated version:
AdafruitGuide_DC_Voltage_bb.png
 

bishoptf

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Ooops, you are right. I also forgot 2 GND connections XD Here's the updated version:
AdafruitGuide_DC_Voltage_bb.png
Might want to check that second 0-10v input looks like its on the wrong side of the cap, doesnt match the first one..actually I think the second is correct and its the first one that needs to be updated. :)
 
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Honestly, just is a worse op-amp then.

(...)
Which one do you mean ? The H-bridge version ?

I wouldn't say that it's worse in every way, it simply maps the input voltage comparatively precisely to 0-VCC. Precise because the PWM has a 16 bit counter, as long as the transistor pair has a nicely matched delay time.
An OP-Amp needs fine adjustment in amplification and likely isn't quite as precise due to the input offsets. For the purposes here that's nitpicking though ^^
 
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Might want to check that second 0-10v input looks like its on the wrong side of the cap, doesnt match the first one..actually I think the second is correct and its the first one that needs to be updated. :)
Darnit, if I continue like that I wont finish correcting all night XD
AdafruitGuide_DC_Voltage_bb.png

Technically you don't need all of the GND connections there, as the LM2596 share a common GND and are not isolated.

One can switch the 2N2222 for the 2N7000 when one replaces the 10k input resistor with a simple wire.
 

bishoptf

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Darnit, if I continue like that I wont finish correcting all night XD
Looks good now, even a blind pig finds an acorn every now and then..I think we should make a separate post to document this diagram just in case someone else may want to do the same thing...:)
 

oreo54

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Afaict except for Meanwell 3 in one dimmable drivers nobody uses 10v pwm.

Early Typhon controllers ( diy gone commercial) had a 10v pwm option.
It had a weird waveform according to stevesleds.

Just to get my own head straight.
The Nicrew is designed to use 10v analog from say an Apex ( full Bluetooth ect.)
Ignoring the "lockout" function the jack board converts this to "not 10v analog".

Correct?
Sorry I know old stuff.
It's converted to some pwm control signal
5 v pwm ???

Any microcontroller that has it's pwm pin converted to a relatively clean 10v dc signal should work fine jacked in. Trs jack should
work fine for 2 channels and ground.



Ok one favor though, the driver ic's haven't been identified yet.
Now the dim circuit continues all the way to the main board.
Sooo drivers should be there.
Is there a number ( Id) of the 3 big ic-s on the diodes board?
Since I don't see any inductors well got me curious.
Linear drivers?
 

bishoptf

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Afaict except for Meanwell 3 in one dimmable drivers nobody uses 10v pwm.

Early Typhon controllers ( diy gone commercial) had a 10v pwm option.
It had a weird waveform according to stevesleds.

Just to get my own head straight.
The Nicrew is designed to use 10v analog from say an Apex ( full Bluetooth ect.)
Ignoring the "lockout" function the jack board converts this to "not 10v analog".

Correct?
Sorry I know old stuff.
It's converted to some pwm control signal
5 v pwm ???

Any microcontroller that has it's pwm pin converted to a relatively clean 10v dc signal should work fine jacked in. Trs jack should
work fine for 2 channels and ground.



Ok one favor though, the driver ic's haven't been identified yet.
Now the dim circuit continues all the way to the main board.
Sooo drivers should be there.
Is there a number ( Id) of the 3 big ic-s on the diodes board?
Since I don't see any inductors well got me curious.
Linear drivers?
The problem I have with the main board is its on standoffs and I'm not sure how to remove it and the chips are on the side that I cannot see. I wouldn't mind taking a pic if I could figure out how to remove it but I am reluctant, it appears to be soldered on the standoffs.

PXL_20230116_184925459.jpg


Here are some pics, I did not circle the stand offs but I swear it looks like they solderd the board to the standoffs..

PXL_20230126_205407205.jpg


PXL_20230126_205422737.jpg


Not sure how to remove them...
 
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oreo54

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The problem I have with the main board is its on standoffs and I'm not sure how to remove it and the chips are on the side that I cannot see. I wouldn't mind taking a pic if I could figure out how to remove it but I am reluctant, it appears to be soldered on the standoffs.

PXL_20230116_184925459.jpg


I can try to get a better pic tonight as to how its attached to the case, odd to say the least.
What is U3?
 

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