3 Responses to “Floyd schematics posted”

  1. Hi there,

    I think your solution is really cool but I may have some comments about LED lightning (part time of my job).

    Changes of the LED color temp due to heat issues -> change in PWM duty cycle to compensate?

    We found out that the overall brightness of the LEDs change radically with their core temperature. If you plan to use this lightning solution over a wide temp range (-25 to 40°C) the LEDs and their current will most likely change at least 1/3 within this range.

    Series or parallel LED strings -> we are using LED strings with up to 25 LEDs and up to 200mA, in general the more voltage you use for the LEDs the better. This also increases the efficiency of the design due to lower copper losses.

    For the battery I would use a flat LiPoly that is directly behind the PCB on the back side. They are a little bit more expensive but enable you to save building volume of your design.

    The enclosure in general looks really nice! Are you planing to weather seal the design? I, personally would coat the finished print and try to use the Aluminium chassis as a heat sink. The whole back side with the display would be one Plexiglas (or whatever) piece. All buttons at least a little bit water resistant (Automotive parts are rather cheap to get).

    I would also think about one version without a display but an bluetooth / zigbee/ wlan? interface where all needed informations are display via an simple App. This would be really great to combine more than one light and steer them together from one interface. (and the display isn’t that cheap -> save the money for a better battery 🙂

    Have you thought about EMI? If your device is operated near flashes huge EMI bursts occur ant they may interfere or disable your device. Usually we place passive filters (lots of capacitors) on all interfaces (in and out). If you plan to power this device via a simple cable from you car battery keep in mind that huge voltage spikes (more than 40V) may occur during normal operation.

    My last idea would be to use the LEDs as a Flash itself. You could overload them for a really short period and increase their light output immense. A fully working RGB Flash, how cool would that be?!

    I really hope your design comes to life and I would like to have one!



    PS.: If some of my comments are offending, please ignore them 🙂

    • Hi Martin, awesome comments!

      We’ve gone to great lengths to deal with the heat issue. The front enclosure is aluminium and work as a heat sink for the emitters. Still, as you mention, we should expect a wide temperature working range. There are at least two strategies to deal with the color and brightness shift: a fixed compensation factor, or a feedback loop. I’ve added a PIN diode in order to test if a feedback loop works out well. Fallback is a fixed compensation factor.

      The current PCB has components on both sides. The emitters on one side and the rest on the other side. So there is no room for a battery. We could split it into two PCBs with a flat battery sandwiched in between. That would be an awesome solution. I guess it would have to be a LiFePo4 battery because of temperature. I don’t have a good source for a quality prismatic battery vendor who would be willing to work with our volumes on this.

      We have discussed weather sealing. It is definitely doable. A silicone rubber cover for the connectors will cost a bit. Plus I don’t have a good solution on weather sealing the buttons yet. Suggestions are welcome. We’ll have to figure out the cost implications.

      I would love to have an app control these lights. If we add a bluetooth radio, do you think someone would be interested in playing around with an app for this? If not, It will be a little while before I get around to it 🙂

      We’ve done quite a bit of work on EMI and ESD. The plan is to get CE and FCC approval.

      The flash functionality has been pushed further out in time. Higher current will give more light but with diminishing returns. We’ll focus on adding awesomesauce to continous light for this iteration! 🙂

      • Hi there again,

        LED heat issue: What about an aluminum core pcb? We are using it for our Power LEDs with great results. Why a PIN Diode? what’s wrong with an LM70 or LM50? I would implement the feedback via software rather than in hardware.

        Battery issue: You could use a split design for the pcb. This enables you to use the Alu core pcb (only one component side possible) and thermally connect it to the chassis. The second pcb is a “normal” pcb and provides the LED converters, …

        Wheather sealing: What if you wouldn’t use any buttons at all? If you use the second pcb as button area? You could use the capacitive touch technology from Atmel. These Buttons are just some traces and you could use the rear plexi cover as button area and no sealing is needed. You could also rather easy implement sliders for each color (RGB and brightness, …) with virtually no costs at all, just PCB space. Backlighting the buttons and adjusting the brightness via a ambient light sensor is also pretty easy if its just a trace.

        Silicone rubber cover: In my opinion you shouldn’t use such methods. Normally covers get lost or are useless. If you use the right connectors weather sealing is possible but not with consumer stuff. If possible cut down on connectors as much as possible. The strain on the solder joints is also not neglectable!

        I bet that somewhere out is interested in doing such an app! I would do it if I were a software guy, but right now I’m more into hardware 🙂

        Enough for now!



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