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About Thierry-GearsManiac

  • Birthday 05/18/1974

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  1. Thierry-GearsManiac

    Applying LED strips

    OK : the measurements you'll obtain (voltages on different LED strips with power turned on, resistance of one resistor with power turned off and preferably for an unused output port) will confirm the assumptions. I wasn't aware that the kit was bundled with the car (a fan's model ?) : I believed it came from marketplaces like EBay.
  2. Thierry-GearsManiac

    Applying LED strips

    A few posts before, about the question if the output ports do generate different voltages : they are identical, then they don't do it by themselves : on ports where no load (one of our LED strips) is connected, the expected voltage is the supply voltage = 9V, because the circuit is open <=> no current flows through the resistor <=> the voltage at its terminals is 0V on ports where a LED strip is connected, the expected voltage will be the LED's forward voltage because the LEDs clamp the supply voltage down to their forward voltage, forcing current to flow through the resistor, which "sees" the difference between the supply voltage and the LEDs' forward voltage. Therefore, with white LEDs, you can expect 3V approximately on the port, and with red and yellow LEDs, you can expect 1.8-2.0V approximately ==> the resistor will then see either 6V or 7.2-7.0V, which results (according to Ohm's law) in a slightly higher current for the red and yellow LEDs than in the white ones. For measuring the voltage on the LED strips, if you don't want to do it on the surface-mount leads of the connectors (they are very close to each other), you may be able to do it on the strips themselves, either on the cables' '+' and '-' solders, or on the '+' and '-' pads between the LEDs. (and for the blown TV's LED, it's the thermal aspect that has not been studied/tested enough by the engineers : when dealing with higher power LEDs, even when operating them below their maximum current, one can destroy them by overheating if not enough heatsinking is provided for draining their heat away)
  3. Thierry-GearsManiac

    Applying LED strips

    @phaenius: After a look at your pictures, I see that the power distribution board has a resistor (SMD, probably 0603 size) in front of each LED strip connector ==> my assumption of three LED dies in each LED package is probably wrong. And since you have red and yellow LEDs, their forward voltages are lower (around 1.8V for red and 2.0V for yellow, versus around 3.0V for pure green and blue/white LEDs). ==> the resistors do matter and are dimensioned for supplying 4 times the nominal current of a single LED (4 LEDs / strip, assuming equal current sharing between paralleled LEDs although it's wrong) ==> don't cut your strips, otherwise you'll overpower = fry your LEDs ! (unless you hack the strips in order to insert extra resistors or reuse only the cable with the female connector in order to build a custom LED circuit) For further hacking purposes, it would be interesting to make the following measurements : the supply voltage (on the black cables' solders)... I guess around 9V since it is today's LEGO standard the LED strip voltages for each colour (on the surface-soldered terminals of the PCB connectors where the strips are connected) the resistor's value (on one of the resistors' terminals, with power turned off and everything disconnected)... unless its value code (3-4 digits or 2 digits + 1 letter) can be read by the help of a magnifier
  4. Thierry-GearsManiac

    Applying LED strips

    On my side, after thinking, according to some clues, I may make this assumption about your LED strips : if they are : powered on a 9V supply (typ. batteries) directly connected to this supply without any extra resistor then : each LED package probably embeds 3 LED dies in series, each one having a forward voltage drop of approximately 3V (typical for blue/white LEDs) the current limitation may rely only on the LEDs' intrinsic resistance (and the batteries' one too), but with the drawback that slight voltage variations lead to large current variations (this resistance is low : a few tens of Ohms) : when the battery charge drops only a bit, the light intensity will decrease significantly one can't power the LEDs on a 12V power supply without instantly overloading = frying them
  5. Thierry-GearsManiac

    Applying LED strips

    @MAB : I remember about fitting a 5mm LED into a technic brick's hole, but it was so tight that the LED's body could not be inserted on its full length without risking breaking the LEGO brick or rendering this insertion permanent. @phaenius : - if you intend to use other power sources (perhaps LEGO ones through the use of a cut LEGO power cable), never connect LEDs directly to them or they'll burn out instantly. Limiting resistors or constant current source modules will be required - I'm indeed curious about the whole lighting kit (either its specs, or reverse-engineering it). And for the concern of it being considered as advertising, perhaps the problem may arise if its brand is a LEGO clone (some are legal and can be discussed here, some others are not and we must not talk about them, for not advertising them), or not : I guess that universal non-LEGO-related lighting kits can be talked about here (after all, some other people do add custom LED lighting to their designs). Instead of pictures, the name of the lighting kit or a link to its supplier's and/or manufacturer's page is possible too.
  6. Thierry-GearsManiac

    Applying LED strips

    Cutting the strip can be more or less "reversed" by re-soldering the cut copper pads together (through a short wire). I noticed on the pictures that this LED strip is very unusual : power LEDs, probably between 20mA and 100mA, slightly smaller than the 5630 type. Technical specs for the LED strip (circuit), the LEDs and even the power supply (constant voltage or constant current type ? For any length of this LED strip ?...) would help to solve the numerous problems. Moreover they seem to be wired directly in parallel, without individual resistors (unless the LED case embeds it, but it would be much more unusual). And having LEDs wired in parallel is usually bad because the current sharing isn't well controlled (and when one LED gets disconnected, then the other ones receive more current, then may fail in cascade because they would get overloaded more and more). Personally, because of the above remark, I don't trust very much this LED strip. In order to gain full control of the current in each LED of it, more advanced hacks would be needed (cutting the strip in single LED bits, powering each of them with individual series resistors, whose values would have to be chosen, depending on the LED forward voltage and the supply voltage... like when designing a LED circuit from scratch). Have you got any idea about the kind of lighting your LEGO designs would need, and if strong miniaturization is a concern, as well than aesthetics (hiding the wiring) ? Some of these informations would help choosing the right lighting solution : - a "long" (several cm) row of LEDs, above/around a stage for example ==> a standard 12V LED strip where the "multiple of 3" constraint won't matter so much (you can center the cut strip), especially if the LEDs are close to each other. - shorter rows of LEDs - LEDs arranged in an array - single LED, either direct lighting or remote lighting (light pipe)
  7. Thierry-GearsManiac

    Applying LED strips

    You can post remotely-hosted pictures ([insert other media] - [insert image from URL]). No restriction to some specific picture hosting services : if you own some website-hosting server space, you can put your pictures there and link to them too. Being in electronics, I can say that, on 12V strips (the most common ones), for electrical reasons (using less power while staying not much sensitive to slight input voltage variations), LEDs are arranged in series of 3 with one current-limiting resistor. Therefore one can only have multiples of 3 LEDs on a cut strip. Then I guess that, when wanting other numbers of LEDs, one has to either hide the unused ones, or modify the strip itself (changing the resistors values, re-wiring some PCB traces...)... or even design one's own lighting solution, for example, when only one LED is needed (there are plenty of online tutorials, but if you need further help, you can still ask me).
  8. Thierry-GearsManiac

    [GBC] Newcomer diving right in custom designs

    Here is it : here is an overview of the core mechanism mounted on a very basic scaffold with a few unfinished test elements : a basic ball ramp (bottom right) the currently tested ball holder (bottom left) + a static structure (right) for pushing its gray 'L'-shaped releasing lever Below is a partial dismantling of the mechanism : on the left, the "stator" + the rotating eccentric (rotation center = lowest round hole of the 28-teeth gear). The current structure has been built with my currently available parts but will be made slightly simpler as soon as I get the right parts on the right, the "rotor" = the cycloidal disc, revealing two main design tricks (guess them !) Since this mechanism is smaller, I currently encounter difficulties in reliably loading/releasing balls passively (like on Akiyuki's design, no "active" mechanism for pushing the balls into or out of the holders) : the input ramp has to be placed very precisely, so that the ball gets fully pushed into the loader, and the ramp must not interfere with the holder's cycloidal path. I guess that the current eccentric radius (1 stud) does not give a wide enough move, but since this configuration can work for now, I'll increase the eccentric radius later (because it involves readjusting the whole cycloidal gearing in order to keep it smooth as now !). The places where balls get loaded and released are also different, because of how they get held (first brainstormed idea I had).
  9. Hi everybody. This is my first post (except the "members' introduction"). Not being sure if it is the correct way/place to start I at last go into posting about my GBC projects, which are all only at WIP stage now. I already watched and read a lot of GBC resources (events videos, standards, famous modules and builders, balls sourcing hints...), which gave me a few ideas of custom builds, which will be new ideas as well as "remakes". But my work is currently slowed down by a few difficulties when leaving the dark age (getting used to studless building techniques when designing custom only, missing parts despite a huge initial BrickLink investment), so the results would show up bit by bit only. So, for more concrete stuff, my most advanced work is on a compact cycloidal drive, of course inspired by Akiyuki's one, but being a fully custom from-scratch and trial-and-error build. At its current state, only the core mechanism is available and it runs smoothly. However the ball transport (currently built on only one cycloidal "tooth") seems to be the hardest thing to make reliable, and it is not yet the case. A stiffer chassis (with the input bin and agitator + secondary ball transport mechanism will be required too. I'll build it with bricks mainly (when I'll find an opportunity to pick up my childhood stock). The core mechanism features an outer ring of 8 teeth, based on an octagon made up of 6L axles and 135° connectors, and a 7-teeth cycloidal disc (and some associated tricks), resulting in approximately 2/3 the size of Akiyuki's original design. So is my prototype worth a picture right now ? (a few other modules are planned but I built only draft/mock-ups of the core mechanisms now due to the lack of parts.)
  10. Thierry-GearsManiac

    New French enthusiast

    mathieulego, Falandrin, Merci pour l'accueil / Thanks for the welcoming... Something I forgot to tell in my introduction about the interest of using LEGO : creativity comes from technical limits, the same way as when coding demos or impressive games on vintage computers.
  11. Thierry-GearsManiac

    New French enthusiast

    Hi everybody. I'm Thierry, from France, currently 45 years old. Back into LEGO since a few weeks only, due to a combination of recent events. Back, because I of course played LEGO a lot when I was a child/teen : - especially with the Technic series since I was 6 years old (I always loved using gears because they impressed me when I discovered them when I was 3 years old) : most often for trying to build things by myself, after building the official models. - later, with the early 80's Space series In general, I was always passionate about mechanics first (clocks, electrical toys...) then electronics, and later computer science (which make my current job : electronic board design, sometimes with embedded software). Some stringent limitations with earlier Technic LEGO parts made me stop using them, especially the inability to rotate gears independently on a same axle (this was before the differential bodies, and the Samsonite gears were totally unknown to me !). For me, the so-named dark age didn't mean forgetting about my special interest in mechanics, playing with non-LEGO parts, either scavenged or, in the beginning of the decade, custom made thanks to 3D-printing. Then, in May 2019, on a makers exhibition, I met PG52 and saw his masterpiece (a detachable chairlift) and also a few GBC modules he assembled or sometimes designed (I already knew about GBC because I already found this by chance several years ago on YouTube and spent a few evenings watching it). After that, watching a lot of GBC-related videos and discovering impressive mechanisms (of course some of them from Akiyuki, especially the Strain Wave gear, but not exclusively), I felt a strong desire to start building LEGO machines again, especially as design limits were reduced, thanks to new parts (for example, geared turntables, gears with round holes) and new LEGO build paradigms (studless, SNOT...). That's why I'm here. Currently putting money in "new generation" spare parts, having ideas for building variations of known GBC modules at a lower scale, a few not yet implemented ideas... perhaps later exploring the building of clocks too... I don't know for how long this delight will last and I have not the will/motivation (and the time and money) to reach the same level as the big fans I admire, but I want to take as much pleasure as I can in playing LEGO again.