Recent content by hevans1944

  1. hevans1944

    power

    PCB design often (always, actually) occurs post circuit design, mainly because it is difficult if not impossible to layout component pads and connections without knowing what the components ARE and HOW they are connected, Some of us are good at circuit design, and some of us are good at turning...
  2. hevans1944

    Newbie Advice Needed Please

    Hmmm. Yet another drive-by poster who is only looking for a "quick answer" and is unwilling to enter into a discussion. If I were writing the software for these forums, I would automagically suspend any account that asks a question and then provides no further interaction. Comments created by...
  3. hevans1944

    RF-ID advice needed

    The key parameter that you need is the position of the train: "...when a train enters & leaves an area", An RF-ID will NOT accomplish this. At best, it will recognize the presence of the train, not its position entering OR leaving an area. I would suggest installing optical sensors at the...
  4. hevans1944

    issue with homemade DC motor + hall effect sensor

    The A3144 has an open-collector NPN transistor output. This needs to be directly collected to the MOSFET gate input and pulled up with a resistor connected directly to the +5VDC supply. That will guarantee there will be enough voltage to drive the MOSFET fully into conduction. Have you made any...
  5. hevans1944

    JK Flip-Flop Toggles Twice from One Button Press

    I just now found one of my missing "round tuits" and read the paper linked to in @Harald Kapp's first response. Very nice analysis of the switch de-bouncie problem. including software solutions. Ignore the software approach if at all possible and use the RS flip-flop instead. Don't waste...
  6. hevans1944

    JK Flip-Flop Toggles Twice from One Button Press

    The only "bullet-proof" way to de-bounce a manually-operated switch is to use a SPDT switch wired to control a simple set/reset flip flop. Some J-K flip-flops have separate set and reset inputs that can be used to implement a set/reset flip-flop. If you use one of these, disable the clock and...
  7. hevans1944

    Comedy Thread

    @Delta Prime: Technically, with two front wheels and one rear wheel, your pedal bicycle is a tricycle.
  8. hevans1944

    Comedy Thread

    In the early 1970s I cudn't even spull inga-near, but now I are one (BEE, 1978, University of Dayton)
  9. hevans1944

    Comedy Thread

    Nice try but this workaround has omitted the "green wire" safety ground. It is NOT safe.
  10. hevans1944

    Found problem in Kenwood KR-V95R

    Nice to see that some of us from "the old days" are still hanging around...
  11. hevans1944

    How can I use an on-grid solar inverter in an off-grid setup using a pure sine wave inverter as a simulated grid?

    Time flies, whether I am having fun or not. [hijacking the thread] Most of my attention the past couple of years has been focused on bouncing laser-emitted light off the surface of the Moon, and detecting the reflection here on Earth for communications purposes. I call this Optical EME...
  12. hevans1944

    I need help with OnStep.

    You might want to head over to the OnStep forum for this: https://onstep.groups.io I need to build a remote-controlled (Bluetooth) equatorial mount for my optical-eme experiments, so I am interested in your project. For purpose of discussion, optical means visible laser light and EME means...
  13. hevans1944

    How can I use an on-grid solar inverter in an off-grid setup using a pure sine wave inverter as a simulated grid?

    I have been pondering this question for quite some time now. Our grid-tied solar system is directly connected to our 200A distribution panel through a disconnect switch. That switch can be used by our electric utility, Florida Power & Light (FPL), to disconnect, and lock out, the solar array...
  14. hevans1944

    IC Insertion tool

    If you can find them, a pair of "duck-bill" pliers works well on smaller DIP devices: a whole line of pins can be bent straight simultaneously.
  15. hevans1944

    Bench power supply upgrade

    I got involved with Arduino a few years ago when I had a Bluetooth project. The project didn't go anywhere, but I still have the Arduino and the Bluetooth boards that plug into the Ardino board. I might revive that part of the project as part of a home automation project that takes advantage of...
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