24v 200ma pwm signal over long cable

MisterBill2

Joined Jan 23, 2018
27,903
The link in post #18 had no mention at all of the voltage or current requirements for those parts. The second link did provide that information.
So the parts described in that second link could certainly be utilized.
That still leaves addressing and dimming to be handled. If the PWM frequency is less than 1000 hertz the longer wires should not be an issue. possibly 400 hertz would be even better.
 

Thread Starter

robinscottlawrie

Joined Feb 15, 2018
96
The link in post #18 had no mention at all of the voltage or current requirements for those parts. The second link did provide that information.
So the parts described in that second link could certainly be utilized.
That still leaves addressing and dimming to be handled. If the PWM frequency is less than 1000 hertz the longer wires should not be an issue. possibly 400 hertz would be even better.
so, the lower the pwm frequency the better for longer wire runs? this is useful information.
 

MisterBill2

Joined Jan 23, 2018
27,903
Almost always, the effects of transmission line reactance increases with the frequency. Resistive effects do not change so much as the frequency increases, except for the "skin effect". But I doubt that it matters much as the low frequencies in this discussion.
 

MrChips

Joined Oct 2, 2009
34,984
Here is how I would do it.

Single 2-wire cable runs to all lamps. You can hide the cabling in the bamboo or plastic conduit colored to match the bamboo.
The cable provides power and data. Each lamp is individually addressable. Data sent has lamp ID, flash mode, intensity. In the bamboo ceiling is a small MCU controller board (or COB - chip on board), no larger than a 25-cent coin, and a single 2-conductor cable that drops down to the LED in the bottle.

You can scale this to any number of lamps.

With 2-wire system, 24 V power is supplied, and 2 V data is transmitted by modulating the supply voltage 22-24 V.
You can also use a 3-wire cable instead of 2-wire where data is transmitted on a separate cable.
 

Thread Starter

robinscottlawrie

Joined Feb 15, 2018
96
Here is how I would do it.

Single 2-wire cable runs to all lamps. You can hide the cabling in the bamboo or plastic conduit colored to match the bamboo.
The cable provides power and data. Each lamp is individually addressable. Data sent has lamp ID, flash mode, intensity. In the bamboo ceiling is a small MCU controller board (or COB - chip on board), no larger than a 25-cent coin, and a single 2-conductor cable that drops down to the LED in the bottle.

You can scale this to any number of lamps.

With 2-wire system, 24 V power is supplied, and 2 V data is transmitted by modulating the supply voltage 22-24 V.
You can also use a 3-wire cable instead of 2-wire where data is transmitted on a separate cable.
do such 25 cent coin boards exist on the market, and is there off-the shelf software i can control them with? if i have to custom make hardware or code the project will never get done.. if so, sounds like a great solution.
 

MrChips

Joined Oct 2, 2009
34,984
I believe there are already addressable LED lighting systems on the market. I have not searched.

If not, there are at least 100 members here on AAC who would gladly design such a system for you.

With COB assembly, the price of each module would drop to less than 25 cents a piece! Here is a marketing opportunity for any budding entrepreneur out there.
 

Thread Starter

robinscottlawrie

Joined Feb 15, 2018
96
Quick 1-minute search.
50 addressable LEDs for US$16.

Addressable LEDs
yes ive used WSxxxx addressable LEDs before .. unfortunately finding single colour (warm white) high power addressable LEDs is harder, and if I wish to use led filament or a cob led strip, this requires an addressable driver suitable for a separate led. these are much harder to find. in fact the ones I have proposed throughout this thread are one of the few on the market, and the only ones I've found after weeks of searching, which offer more than 8 bit (256 brightness levels) this is important for pleasant fade effects at low brightness levels. even then, these are 3 channel minimum, and constant voltage, not constant current. if I could find a single channel constant current driver using one of the newer addressing protocols (more than 8 bit) I would jump on it.

another thing to consider is all these (protocols that I've seen) are minimum 3\4 wire setups, with data, and sometimes clock, on separate pins. believe it or not I have actually done my research.
 

MrChips

Joined Oct 2, 2009
34,984
yes ive used WSxxxx addressable LEDs before .. unfortunately finding single colour (warm white) high power addressable LEDs is harder, and if I wish to use led filament or a cob led strip, this requires an addressable driver suitable for a separate led. these are much harder to find. in fact the ones I have proposed throughout this thread are one of the few on the market, and the only ones I've found after weeks of searching, which offer more than 8 bit (256 brightness levels) this is important for pleasant fade effects at low brightness levels. even then, these are 3 channel minimum, and constant voltage, not constant current. if I could find a single channel constant current driver using one of the newer addressing protocols (more than 8 bit) I would jump on it.

another thing to consider is all these (protocols that I've seen) are minimum 3\4 wire setups, with data, and sometimes clock, on separate pins. believe it or not I have actually done my research.
I believe you that you have done your research.

If none is available on the market, the next step is a DIY solution.
 

Thread Starter

robinscottlawrie

Joined Feb 15, 2018
96
Not to mention those strings in post 27 are only .3 watts.

I believe Adafruit has some 4-watt NeoPixels.

Ultra Bright 4 Watt Chainable RGBW NeoPixel LED - Cool White [~6000K] : ID 5162 : Adafruit Industries, Unique & fun DIY electronics and kits

Not sure if they would fit in those bottle necks.
I did consider them and they might fit, but I'm unfortunately im not after a point light source and I have no need for RGB.. seems a waste to get a 4 watt RGBw with a 4 channel control chip just to use white

regarding the filaments, I have found some that are longer (up to 1m!) and flexible . those are more than 0.3w .I think I can fit a 30cm one in using the system I have In mind
 
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