Search results

  1. Fish4Fun

    Hovering Drone....W/Kg Calculation.....

    While not strictly electronics, the physics of a "hovering quad-copter" is a modern manifestation of a problem that has plagued me since high school physics.....the definition of work is Force x Distance and since "hovering" by definition is not moving.....there is a tad of a SNAFU calculating...
  2. Fish4Fun

    H2O Auto-Fill Schematic Sanity Check

    Before I start building this I was hoping for a quick sanity check....The purpose of the circuit is to Auto-Fill a 250 gallon water tank we use @ my business to supply water to our live bait tanks. The water is used throughout the day and is supplied to the 250g tank from a well. Because well...
  3. Fish4Fun

    Sensorless BLDC motor driven synchronously.....hrmmm...

    So I have been playing with some small sensorless BLDC motors (hobby small, not industrial small, lol)......I have read tons of white papers and application notes and certainly understand the how and why of sensing the zero crossing point and all of the caveats, foibles and pitfalls...
  4. Fish4Fun

    Thoughts on the Turing Test.....

    So we are all clear: So, in a casual conversation about an online entity, I suggested that perhaps the entity was a "bot" that could manage a few rounds of a Truing test, and someone stated: Obviously the statement is True, but in the process the underlying question becomes, "How many...
  5. Fish4Fun

    Dell Laptop Touchpad......

    This post is really more of an "experience" question than electronics..... I have been using various Dell Notebooks for a long time.....mostly the D620/E6500 series for the last 10 years or so....I always keep a "back up" because being "down" for a couple of days pretty much means my world...
  6. Fish4Fun

    Getting Started with FPGAs.....

    I have been fascinated with FPGAs since I discovered them in a Digikey Catalog back in the 90's.....I even went so far as to order a "dev board" a decade or so ago...(...but I never got around to actually doing anything with it...not even sure where it might be at this point....)....so now I am...
  7. Fish4Fun

    3-Phase VFD Supply Pre-Filter

    I am finishing up a CNC router build and have opted to use a "stock" 3-phase spindle rather than a DIY spindle. I have received the spindle and the VFD and am wading through the instruction manual and various forum posts about set-up, problems, etc, etc. This is the VFD...
  8. Fish4Fun

    Selecting PWM Freq for Speed DC Motor Control

    What I have is a 120Vdc brushed, 16-field "surplus" motor in the ~1.5hp range @~18krpm with a date of mfg of 1978. What I am working on is a belt-drive spindle for a CNC router where the spindle speed needs to be variable from ~1krpm to ~6krpm, the belt reduction is 3:1. This is a one-off...
  9. Fish4Fun

    Mosfet Selection....

    Just read a response KrisBlueNZ made to a thread on a motor speed controller where he recommended a NTD4906 mosfet as a good choice for a low-voltage//low gate threshold switch..... First, Great Catch! Sepcs on that little mosfet are fabulous and they are virtually free! But that isn't really...
  10. Fish4Fun

    Alternative Energy.....

    AE (Alternative Energy) seems to be @ the forefront of everyone's mind, so perhaps there should be a "sticky" thread that covers some of the basics....With this in mind, let's use this thread to "hash out" some of the common misconceptions, problems and "answers" to some of the more common...
  11. Fish4Fun

    IR2110 Mosfet Driver Capacitance Question

    I have just assembled 3 * IR2110 Hi/Lo Side Drivers onto a PCB I mocked up to do some BLDC motor tests...for the High-Side Floating Supply I have 1 * 0.1uF Ceramic, 5 * 4.7uF Ceramic and 1 * 68uF electrolytic (obviously in parallel)...I realize 6 Ceramic Caps are over kill but I wanted to make...
  12. Fish4Fun

    JBOD Wish Device

    So we all have some media files we like to play on various devices and at some point we all have to consider storage space, convenience, power consumption, cost and data integrity...personally my current solution is a 7-Bay linux based NAS configured in RAID6 (RAID5 with an extra parity disk)...
  13. Fish4Fun

    SSR Heat Sinks

    In addition to my electronics hobby, I have a home brewing hobby. I have a fairly large system for a hobbyist, and do 20-25 gallon "batches". Regardless of scale, brewing requires a fair amount of heating water (and then cooling it back down, hehe). I started with Propane, but for various...
  14. Fish4Fun

    IR Laser for Comm

    I have the most complex residential water system in history, won't go into details, but I would like to monitor some facets of it. The "water shed" is ~75ft from where I would like to monitor it. The obvious/simple answer is to run a wire, but what fun would that be? The next obvious answer...
  15. Fish4Fun

    Pieces Parts and tools....What's on your bench?

    This is a sort of rambling attempt to glean information by sharing information. It started off as a post about diodes, but I just couldn't stop, LOL, so here is a laundry list of what is on/around my bench and out in my shop as well. If you have something in your DIY inventory that I haven't...
  16. Fish4Fun

    Thoughts on a switch

    So in my life I have been playing with electronics and water for a very long time. I thought I had a pretty good grasp on both, but I am a bit perplexed.....I ordered a couple of these...
  17. Fish4Fun

    To the ADMIN(s)

    Of late when I click "submit" i get the error message about not not posting within 30 seconds of a previous post. Obviously the entry was "double entered" as if I had hit the submit button twice, and "cancelling" and returning to the thread reveals my post was in fact accepted. Sadly I...
  18. Fish4Fun

    AC Relay/Contactor Powered by DC

    AFAIK the only physical difference between an AC relay//Contactor is that a DC relay relies entirely upon the DC resistance in the coil to limit current where as an AC relay/contactor uses the impedance. ^ | | If this is false, then I need someone to set me straight. So, if I have...
  19. Fish4Fun

    H-Bridge Circuit Design

    I would like to build a 4 channel H-Bridge suitable for driving an inductive load (predominantly three-phase "BLDC" and steppers, but also for testing the reactive components of an SMPS) Rather than being a dedicated driver for any particular motor, I would like to build a "prototyping" driver...
View older results
Top