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  1. (*steve*)

    Why would sections of an RGB LED string freeze animating after 30 mins?

    Yes, it is almost certainly timing related. However it is probably also related to temperature. Various factors can reduce the tolerance to out of spec signals. We've covered reduced voltage, now we're investigating the possibility that long cable are causing a problem. Whilst cable length...
  2. (*steve*)

    Why would sections of an RGB LED string freeze animating after 30 mins?

    Some background on those questions: there have been issued reported when the connections between the chips are too long. To combat this, some people insert another module/chip to break up excessively long cable runs. If these are not wanted they are covered in heatsink of otherwise blacked...
  3. (*steve*)

    How do you connect all the voltages together into one?

    Not unless it is a completely independent power supply, not sharing any common rail. Another option is that they share the ground rail and one of the power supplies generates a negative voltage.
  4. (*steve*)

    torque question

    Yep. That looks right. Obviously it's a different motor for 12 and 24 volts.
  5. (*steve*)

    torque question

    500W is 500W. However, given that the batteries will weigh pretty much the same for the same capacity, a higher voltage means lower current and hence less weight in wiring (but this isn't going to be a huge issue). Ah is a measure used to help describe the amount of energy in a battery. If...
  6. (*steve*)

    How can we Improve EP in 2017?

    2kW
  7. (*steve*)

    Li ion Battery charge and use circuit

    You can't put power through a regulator backwards. Set the maximum voltage to the charge cutoff voltage, and the current to the appropriate value for the battery. If there is no load, the current will tail off as the battery charges. This approach is simple and reasonably safe, however it is...
  8. (*steve*)

    about led brightness and angle

    You want the LEDs to overlap. This will have them overlapping significantly. Remember that the intensity falls off with angle. If they didn't overlap you'd have hot and cold spots all over the place.
  9. (*steve*)

    about led brightness and angle

    You want the LEDs to overlap. This will have them overlapping significantly. Remember that the intensity falls off with angle. If they didn't overlap you'd have hot and cold spots all over the place.
  10. (*steve*)

    about led brightness and angle

    That would be a good place to start
  11. (*steve*)

    about led brightness and angle

    Well, if they are indeed 120° LEDs, the spacing should be approximately equal to the height.
  12. (*steve*)

    about led brightness and angle

    A colleague of mine is building an exposure box using LEDs. I recommended a hexagonal arrangement of LEDs but he found a regular matrix provided better illumination at the corners. Whatever method you use, the combination of height and distance between LEDs should allow for a lot of overlap...
  13. (*steve*)

    Why would sections of an RGB LED string freeze animating after 30 mins?

    Hie long is the cable run from the controller to the first LED? Edit: I've reread the whole thread again. You note that "sections" fail. Are the sections which fail consistent? If there something significant about the first LED in these sections (e.g. They are connected by wires to the end...
  14. (*steve*)

    Cheap Motion sensors , chinese I think

    The Ronne ice shelf is at the head of the Weddell sea. I am neither in Melbourne or Greek, however the phrase in question is rather appropriate for large swathes of the USA. My location is specified in an unusual way as a bit of a puzzle. Several people have solved it, but you can't use maps.
  15. (*steve*)

    Cheap Motion sensors , chinese I think

    The first digits of the marking are the first digits of the resistance. The last digit is the number of zero's following. 684 = 680 000. Your measurement of 660k is well within the bounds expected. 303 is 30 000. Given your measurement, are you sure it's not marked 304, of maybe 3003? Or...
  16. (*steve*)

    Basic Soldering advice

    I may have, but I didn't inhale.
  17. (*steve*)

    Basic Soldering advice

    Can you smoke it? Oh, damn. That message was back on topic!
  18. (*steve*)

    Multiple mosfet driving

    The beauty of mosfets is that they (source resistors) are not required. Rds increases with temperature. As long as the devices are reasonably matched, they will share current quite well.
  19. (*steve*)

    Multiple mosfet driving

    I realised that the original post doesn't contain details about the actual current being switched or the voltage across the mosfets when they are off. I'll make some assumptions and the OP can substitute real values into my equations. Ids = 80A / 4 = 20A (assuming 80A total across 4 mosfets)...
  20. (*steve*)

    Multiple mosfet driving

    I can do calculations based on 10k, but an emitter follower has a resistor connected between the emitter and a supply rail, with the collector connected to the other supply rail. I'll go ahead with some very generous assumptions, but they may not be valid without knowing more about the driver...
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