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Have BSEE, design Halloween effects including robots, and party lighting effects.

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  • The Lightning Machine: How to Build a Tesla Coil

    Your comment about "experimenting with the secondary", but your illustrations show experimenting with the primary.

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  • bpark1000 commented on seamster's instructable Golf Ball Puzzle1 week ago
    Golf Ball Puzzle

    Boil the water first to remove dissolved air.

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  • bpark1000 commented on JP'sW's instructable Make a Cool Light from a Whiskey Bottle2 weeks ago
    Make a Cool Light from a Whiskey Bottle

    Stand the bottle at a 45 degree angle in the water, keeping the water level below the bottom of the label, but above the hole. Fill the interior to the same level as the outside when the bottle is so positioned.

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  • bpark1000 commented on JP'sW's instructable Make a Cool Light from a Whiskey Bottle2 weeks ago
    Make a Cool Light from a Whiskey Bottle

    No need to fiddle around with putty dams!Put the whole bottle in a tray flooded with water so the side of the bottle is just covered with water. This cools the glass as it is being cut, both from the inside and the outside, and totally eliminates the glass dust. If you use a battery-powered drill, there is no shock hazard doing this.You can also use the diamond core bits, which cut out only a ring of material, and so cut faster and with less heating. Run the RPM higher with these bits.You must completely dry the interior of the bottle before adding the lights.

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  • bpark1000 commented on tanner_tech's instructable Tesla Coil Winding: The Easy Way2 weeks ago
    Tesla Coil Winding: The Easy Way

    I find it easier to fit 2 wood plugs into the ends of the pipe with 1/4' holes in them, and insert a 1/4-20 all-thread rod through with nuts on the ends. A wood crank handle is affixed to one end of the rod with nuts. a frame made of a piece of 2 x 4 (the "lathe bed") and 2 scraps of plywood on the ends (for the "headstock" and "tailstock"). because you are hand cranking, you have more control, and can recover from crossed turns, etc. Also advisable is to add a friction brake to hold things in position when not holding the crank. This can be built on any scale, but for really large coils, 2 people work best. The spray painting can also be done while the coil is on the 'lathe".

    In the photo you have the magnet wire contacting the aluminum member while winding the coil. You should avoid having the wire contact anything other then itself, wood, or other soft materials or your skin, as you may scrape the insulation. Anything it contacts should be rounded. In your case a strip of masking tape over the metal edge will fix this.When cleaning the pipe, use acetone after your other cleaning. This will soften the pipe a little and enhance adhesion. You may want to pre-coat the pipe with the spray before winding.Also be sure to check the inside of the pipe for dirt, and prepare the means of end-termination before starting the winding.

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  • bpark1000 commented on Jaronv's instructable Upgrade/Replace Brushless Motor Magnets2 weeks ago
    Upgrade/Replace Brushless Motor Magnets

    Normally, these motor controllers use a standard servo PWM signal to operate. You can use a micro-controller, or a 555 timer with a pot control to generate this signal. Typically, signal goes between 0 and 5 volts, and has a rep rate of about 60 Hz (not critical), and a "high time" that varies between 1 milli-second (for extreme "low"end of control range) to 2 milli-seconds (for the extreme "high" end of control range).

    There are many more details of the motor construction that determine the way the magnets must be placed. The winding configuration must be such that all the coils in a phase have the same (or similar) relation to the magnets, or the forces will not "add up" within the motor. Most motors of this type are of "high pole count" type. Each coil links only the iron between 2 adjacent slots. There are usually either 6, 9 or 12 slots. The number of magnets must be even and "close" to the number of slots. So 9 slots/8 or 10 poles, and 12 slots/14 or 16 poles is common. The number of poles must have at least one factor of 3 not common to the number of slots (so, for example, 9 slots/12 poles is OK as they have one factor of 3 in common, but the 9 has a factor ...see more »There are many more details of the motor construction that determine the way the magnets must be placed. The winding configuration must be such that all the coils in a phase have the same (or similar) relation to the magnets, or the forces will not "add up" within the motor. Most motors of this type are of "high pole count" type. Each coil links only the iron between 2 adjacent slots. There are usually either 6, 9 or 12 slots. The number of magnets must be even and "close" to the number of slots. So 9 slots/8 or 10 poles, and 12 slots/14 or 16 poles is common. The number of poles must have at least one factor of 3 not common to the number of slots (so, for example, 9 slots/12 poles is OK as they have one factor of 3 in common, but the 9 has a factor of 3 "left over" that 12/3 does not have).The safest thing to do is match the number of poles the original motor had, unless you want to study the details of the winding.

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  • bpark1000 commented on josemivaz's instructable Laser Printed PCB's, Perfect and Easy.3 weeks ago
    Laser Printed PCB's, Perfect and Easy.

    CAUTION! If you choose to use acid/hydrogen peroxide mix for etching, be sure you COMPLETELY rinse it off with running water, then dry COMPLETELY, before applying the acetone. If you don't, you can accidentally end up with acetone peroxide, which is EXPLOSIVE!NEVER allow acetone to mix with hydrochloric acid and hydrogen peroxide!

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  • bpark1000 commented on How-ToDo's instructable Simple Tesla Coil1 month ago
    Simple Tesla Coil

    That is explained in detail in my previous comment. My guess it will be in the 0.01 uF range. It is selected to resonate with the primary alone, at the same frequency that the secondary resonates with its top loading sphere only, with the bottom grounded. I can't give value, as that depends upon the diameter of the secondary, number and spacing of turns, and the loading capacitance of the sphere you choose. I would have to build an exact "carbon copy" of the coil to determine that. That's why I included the long-winded explanation of how to determine the value in the previous comment.If you don't have test equipment, you can build an oscillator from a CMOS chip, a capacitor, a resistor, and a pot. Wave shape is not important, but stable amplitude is, which a CMOS oscilla...see more »That is explained in detail in my previous comment. My guess it will be in the 0.01 uF range. It is selected to resonate with the primary alone, at the same frequency that the secondary resonates with its top loading sphere only, with the bottom grounded. I can't give value, as that depends upon the diameter of the secondary, number and spacing of turns, and the loading capacitance of the sphere you choose. I would have to build an exact "carbon copy" of the coil to determine that. That's why I included the long-winded explanation of how to determine the value in the previous comment.If you don't have test equipment, you can build an oscillator from a CMOS chip, a capacitor, a resistor, and a pot. Wave shape is not important, but stable amplitude is, which a CMOS oscillator will give you. The important thing is that you can "make the same frequency twice" by marking the pot position when you test the secondary, and tuning the primary to "dip" at the same pot setting.

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  • bpark1000 commented on How-ToDo's instructable Simple Tesla Coil1 month ago
    Simple Tesla Coil

    The unmarked capacitor is selected to tune the primary's resonance to match that of the secondary. Diode, earth ground, and sphere on top are shown. What you do is: wind secondary, and put sphere on top. Drive bottom end of primary with signal generator (or kludged-together oscillator) connected through a 1K resistor. Ground other terminal of generator. Do not make any other connections. Put meter from ground to the 1K/secondary node. Turn on generator to a couple of volts. When you are out of resonance, meter will read generator's voltage (as expected, you have no circuit "connection"). Sweep the generator. When you hit resonance, the meter will show a dip in voltage. (This should happen at about 1 MHz). You know you have it when waving hands around secondary dist...see more »The unmarked capacitor is selected to tune the primary's resonance to match that of the secondary. Diode, earth ground, and sphere on top are shown. What you do is: wind secondary, and put sphere on top. Drive bottom end of primary with signal generator (or kludged-together oscillator) connected through a 1K resistor. Ground other terminal of generator. Do not make any other connections. Put meter from ground to the 1K/secondary node. Turn on generator to a couple of volts. When you are out of resonance, meter will read generator's voltage (as expected, you have no circuit "connection"). Sweep the generator. When you hit resonance, the meter will show a dip in voltage. (This should happen at about 1 MHz). You know you have it when waving hands around secondary disturbs meter reading.Wind the primary over the secondary, tape it, and then slip it off the secondary, but keep the form intact. Connect cap in series with primary, and sweep with generator as for secondary, except "far end" of primary is grounded. Adjust cap value until primary resonates at same freq as secondary.Slip primary back on secondary, connect cap in parallel with primary, and proceed with Tesla coil assembly/test.

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  • bpark1000 commented on Renard_Bleu's instructable Potent Pirate Smoke Ring Cannon1 month ago
    Potent Pirate Smoke Ring Cannon

    I made the cannon from aluminum sheet, scaled up some from "Airzooka" toy, and put a large long-throw subwoofer driver. I found the optimum pulse shape to be complicated by experiment (involving a back movement followed by front movement, followed by back).

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  • bpark1000 commented on mikeasaurus's instructable head in a jar prank1 month ago
    head in a jar prank

    Problem is that inner beaker will try to float, a lot! You will need lead weights in inner beaker.

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  • bpark1000 commented on MadeleineDouglas's instructable How to Choose Lumber1 month ago
    How to Choose Lumber

    The trouble, nowadays, that is not good enough! "Perfectly good" boards twist and bend up into wood only fit for the fire-pit in a few months. The only thing that can't happen is more knots "move in"! What you need at the lumberyard, is a crystal ball!

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  • bpark1000 commented on How-ToDo's instructable Simple Tesla Coil1 month ago
    Simple Tesla Coil

    It is a Tesla coil if the secondary's coupling to the primary is low, and the secondary is resonant. When a relatively large secondary is made, the capacitance to ground tends to dominate, making this a Tesla coil if the primary is driven at that resonance. That is forced as he is using current feedback to the transistor's base.What I would do is add an "anti-parallel" diode (most likely a 1N4148 or 1N914) across the BE junction (cathode banded end to B, anode to E) to carry reverse cycle of AC safely around transistor's BE junction, otherwise transistor could fry. Also a smooth metal toroid or ball on top would improve voltage output, and the E lead/battery minus lead should be grounded.How long of a spark do you get?

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  • bpark1000 commented on How-ToDo's instructable Electromagnetic levitation device1 month ago
    Electromagnetic levitation device

    It "is a Levitron". Levitron makes a variety of products that levitate magnets, and some of them involve actively-controlled levitation, such as shown here.

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  • bpark1000 commented on ericsnis's instructable Size Markings for Wrenches and Sockets2 months ago
    Size Markings for Wrenches and Sockets

    Try this method of removing the excess paint: select a solvent that the paint is not compatible with. For the oil-based paints you are using, denatured alcohol is good. Put that on the rag. Apply the paint to the tool, but do not wait for it to dry. Wipe immediately lightly with the rag. What will happen is that the paint will congeal on contact with the (non-compatible) solvent. The paint on the surface will ball up and slide off, like the way dried rubber cement does, but that in the groove will congeal and stay there. I use this technique to "silk screen" circuit boards made on a circuit board router. I first rout the "silkscreen" with a 10 mil cutter 10 mils deep, apply Naz-Dar oil-based silk screen ink with a razor blade, when wipe off the excess with th...see more »Try this method of removing the excess paint: select a solvent that the paint is not compatible with. For the oil-based paints you are using, denatured alcohol is good. Put that on the rag. Apply the paint to the tool, but do not wait for it to dry. Wipe immediately lightly with the rag. What will happen is that the paint will congeal on contact with the (non-compatible) solvent. The paint on the surface will ball up and slide off, like the way dried rubber cement does, but that in the groove will congeal and stay there. I use this technique to "silk screen" circuit boards made on a circuit board router. I first rout the "silkscreen" with a 10 mil cutter 10 mils deep, apply Naz-Dar oil-based silk screen ink with a razor blade, when wipe off the excess with the alcohol rag. Then I proceed with the drilling the holes and routing the traces (I must be careful to not "cut" traces with the silkscreen printing).

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  • bpark1000 commented on Von Malegowski's instructable How to Cut Glass Bottles2 months ago
    How to Cut Glass Bottles

    After scoring the bottle all around, you can also use tiny hammer blows to start the crack. But the blows must come from the opposite side the score-line is on. Take a piece of #12 solid copper electric wire, and fasten a 1 oz fishing sinker or other heavy small object. Bend a curve into the wire so the sinker can be inserted into the bottle and strike behind the score-line, until you see a silver cast to the line, indicating the crack is started. Work around, tapping at the end of the crack to grow it around the bottle.This is the same method used to cut flat-glass, except for the modification to get the hammer inside the bottle.

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  • bpark1000 commented on MrJonesEducation's instructable Frankenstein Light Switch2 months ago
    Frankenstein Light Switch

    You could add 2 fake knife-contacts for additional realism. These could be made of thin spring-brass, fastened to the wood face under where the bars come, and bent into a "U" to just lightly touch the bars when the switch is thrown.To answer to those who have "standard" US switches, the center bar could have a crank that actuates the switch (the axle would be broken in the center with the crank in the center over the switch handle), with lost motion as the switch handle only swings through about 90 degrees, versus the 180 degree swing of the Frankenstein switch.

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  • bpark1000 commented on PaulGetson's instructable Quick and Easy Jacobs Ladder2 months ago
    Quick and Easy Jacobs Ladder

    The smart thing to do is to enclose the ladder in a transparent glass or plastic tube. The ends need to be open to allow air to rise through the tube. This helps the arc rise (the slightest room air currents disturb the arc). The tube also addresses the primary issue: safety.An interesting varient of this is to make the ladder helical.

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  • bpark1000 commented on The Oakland Toy Lab's instructable Splitting Water the Easy Way3 months ago
    Splitting Water the Easy Way

    True, if you allow the liquid in the cell to mix freely. In fact, much trouble is gone to to prevent this mixing to make lye (sodium hydroxide) and chlorine by electrolyzing salt solution.

    What I use for the salt is sodium sulfate. It is non-hazardous, and is neither acid nor alkaline.

    They are right, you get chlorine gas instead of oxygen.

    Hydrogen: cracked from methane (natural gas) or by reaction of coke and steam. Oxygen: fractonal distillation from the air (large quantities) or by pressure swing adsorption (for quantities usually for medical oxygen).

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  • bpark1000 commented on claudiosousa's instructable Globe Persistence of Vision3 months ago
    Globe Persistence of Vision

    Regarding your comment about changing angular speed versus power draw to the rotating LEDs: I see no reason why there should be any impact at all to the the motor speed. The motor is (I assume) powered by a totally independent power source. The rotary transformer, being totally rotationally symmetrical, causes absolutely no load torque on the motor, (other than the "windage" air friction of the rotating coil, which is constant). (It does not extract power from the rotation). I would have 2 coils, each about the diameter of the globe, with perhaps a dozen turns each, one just inside the other, plane perpendicular to and centered on the shaft, mounted under the base plate; inner one rotating with the rotor, the outer stationary, and driven with a half or full bridge circuit...see more »Regarding your comment about changing angular speed versus power draw to the rotating LEDs: I see no reason why there should be any impact at all to the the motor speed. The motor is (I assume) powered by a totally independent power source. The rotary transformer, being totally rotationally symmetrical, causes absolutely no load torque on the motor, (other than the "windage" air friction of the rotating coil, which is constant). (It does not extract power from the rotation). I would have 2 coils, each about the diameter of the globe, with perhaps a dozen turns each, one just inside the other, plane perpendicular to and centered on the shaft, mounted under the base plate; inner one rotating with the rotor, the outer stationary, and driven with a half or full bridge circuit/oscillator from the DC supply in the KHz. The rotating coil's output would be rectified by a diode bridge, and fed to the DC/DC converter you now have.You could also use a coil set with ferrite cores for more compact assembly. If you want to know how to design the transformer, I can explain.(I got a "404 error" on your github link. I tried a search in github on claudiosousa and got nothing)The problem I have with C is that it was designed for PCs, which have basically a big bag of RAM, which is loaded with the program in question, then executed. If the program didn't write something in RAM, garbage is assumed to be there, so you can't "look up" something you didn't write FROM THE PROGRAM. On the other hand, embedded machines have programs usually in ROM, which not only have executable code, but also data ("look up") tables on ROM. A BYTE or WORD directive loads ROM with tables in assembly. C is awkward when dealing with look-up tables, and that is 90% of my programming consists of. (My typical object files are 80% tables and 20% code). C also doesn't "know" about machine-specific things such as the carry flag. The other thing I can't do is debug code WHILE IT RUNS, which I can do with my 65816 and 6808 systems. I could never get the stuff to work if I couldn't do that! For example. Say an interrupt routine "is done". I want to jump back to the debug kernel, so I can debug with the leftover cycles, before the next interrupt comes. Where is the debug kernel? The complicated operating systems don't tell me where or what that is! It is all wonderfully hidden behind all the GUI "eye candy" I don't need! I wish someone could tell me how to do things like this. I would be satisfied with a debugger that can read/write registers, go and stop, a simple assembler, a good data sheet on the processor, and no JTAG peripheral stoppage when in "debug" mode to interfere with running interrupts.

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  • bpark1000 commented on claudiosousa's instructable Globe Persistence of Vision4 months ago
    Globe Persistence of Vision

    I researched Mercotac sliprings. Regulations prohibit the sale of these to "consumers" because of the mercury content. How did you get yours?

    When you create an Instructable, you need to include all relevant details. I saw nothing about this at all (did I miss something?) This is a key part of the project.I built a similar device, much cruder in that it had only 7 monochrome LEDs, but used a rotary transformer (4" diameter close-coupled open-air coils operating at about 32KHz) to convey both power (1/2W) and data (32Kbit/s) to the rotating part. This would have allowed you to eliminate the belt/pulleys and direct drive, as no access is needed at the center or rotation. You must be careful that the center of rotation of the shaft is accurately aligned with that of the slipring, or the slipring will bind and fail.I am frustrated by the "new movement" in processing going to C code only, along with the "ba...see more »When you create an Instructable, you need to include all relevant details. I saw nothing about this at all (did I miss something?) This is a key part of the project.I built a similar device, much cruder in that it had only 7 monochrome LEDs, but used a rotary transformer (4" diameter close-coupled open-air coils operating at about 32KHz) to convey both power (1/2W) and data (32Kbit/s) to the rotating part. This would have allowed you to eliminate the belt/pulleys and direct drive, as no access is needed at the center or rotation. You must be careful that the center of rotation of the shaft is accurately aligned with that of the slipring, or the slipring will bind and fail.I am frustrated by the "new movement" in processing going to C code only, along with the "baggage" of "operating systems" and libraries such as the Arduino. It is almost as bad as a PC! I found out that an Arduino is slowed by a factor of more then 100 by the "system calls" to set a byte to a port. This precludes using "real-time" code that can function in the microsecond time frame (required for generating and decoding the transformer signals, in addition to operating the display). If I could program Arduino (or other processor) in only assembly with all libraries eliminated, I would pursue more projects like this. Now I am stuck with older processors (6808 and 65816) that are not burdened with all this baggage. I can even debug code while it is running!Where did you get the slipring? Mercotac? What did it cost? (You might want to put this in the Instructable). Did the "mercury police" come after you? what keeps the mercury from escaping? (There have to be rotating seals with a finite lifetime).

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  • bpark1000 commented on MakerIan's instructable Make Rochelle Salt4 months ago
    Make Rochelle Salt

    How to grow large crystals under more control: get container for the solution that can be lidded at top. Put saturated solution in with excess crystals on the bottom. Put container in constant-temperature room. Apply slight heat to bottom continuously. Tie seed to fine fish line and suspend in container toward upper part (pass lint through small hole in lid, and close lid). If you get everything right, the initial solution will be a little undersaturated initially, so will dissolve into the seed, removing stray tiny crystals on the seed, but not so much as to dissolve the seed off the line. The temperature gradient causes convection in the solution, the solids at the bottom to dissolve, and the seed to grow. As long as there are solids on the bottom, the growth can continue as lo...see more »How to grow large crystals under more control: get container for the solution that can be lidded at top. Put saturated solution in with excess crystals on the bottom. Put container in constant-temperature room. Apply slight heat to bottom continuously. Tie seed to fine fish line and suspend in container toward upper part (pass lint through small hole in lid, and close lid). If you get everything right, the initial solution will be a little undersaturated initially, so will dissolve into the seed, removing stray tiny crystals on the seed, but not so much as to dissolve the seed off the line. The temperature gradient causes convection in the solution, the solids at the bottom to dissolve, and the seed to grow. As long as there are solids on the bottom, the growth can continue as long as desired. Growth rate is controlled by amount of bottom heat applied. Saturation can be short-term adjusted by altering total temperature (a slight warming at the start can be used to dissolve into the seed at the start). There is a Scientific American Amateur Scientist article about this, but you will have to order the CD to get this.

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  • bpark1000 commented on claudiosousa's instructable Globe Persistence of Vision4 months ago
    Globe Persistence of Vision

    Not explained anywhere I can find is a means to get power and signals from the stationary parts to the rotating parts. Is there a slipring or rotary transformer somewhere?

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  • bpark1000 commented on darbinorvar's instructable How To Build a Shed4 months ago
    How To Build a Shed

    The copper compounds in the newer treated wood corrode "ordinary" galvanized steel screws like crazy! It is best to use stainless steel, or the screws will be gone in a year!Another thing to note, is that the newer "treated" wood (that is arsenic free) is mostly not rated for continuous ground contact. I would use the new "plastic lumber" at the bottom. Even then, termites could build tubes over the base (on the inside of the base, where it can't be seen) and into the floor and walls.

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  • Getting Started with NeoPixel / WS2812  RGB LED

    Does anyone have a timing diagram of the signals required? (Otherwise, I am forced to reverse engineer it from the code.) I assume that the signals are of high frequency (in the millions of bits per second), as these ICs demand at least 24 bits per pixel per update. How is this high-speed data stream gotten from the Arduino, which only has a 16MHz clock? Are the core routines written in assembly, or is there some sort of peripheral processing?Regarding the comments about noise concern, keep one thing in mind. Each IC in the chain re-processes and cleans up the signal before sending it to the next IC. So there can be a lot of ground noise in the system, as long as it is not concentrated between 2 adjacently-connected LED ICs. So I would avoid breaking up the power buss as explain...see more »Does anyone have a timing diagram of the signals required? (Otherwise, I am forced to reverse engineer it from the code.) I assume that the signals are of high frequency (in the millions of bits per second), as these ICs demand at least 24 bits per pixel per update. How is this high-speed data stream gotten from the Arduino, which only has a 16MHz clock? Are the core routines written in assembly, or is there some sort of peripheral processing?Regarding the comments about noise concern, keep one thing in mind. Each IC in the chain re-processes and cleans up the signal before sending it to the next IC. So there can be a lot of ground noise in the system, as long as it is not concentrated between 2 adjacently-connected LED ICs. So I would avoid breaking up the power buss as explained in some of the comments. For long busses, put feeders every so often, but do not break up the continuous power rail. Yes, there will be ground loops, but this noise will be distributed, and will not disrupt the signal.

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