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  1. hevans1944

    Adding Frequency Scanning to any AM/FM/SW Radio

    When I was young, I had to crawl 9 feet over a bare, highly waxed, floor just to turn the television ON! We had no need to change the TV channel because there was only one channel that the "rabbit ears" antenna, sitting in its glorious place on top of our Hoffman Easy Vision monochrome...
  2. hevans1944

    Have you ever used a MCU to connect to a LCD ?

    @bancroft: This is a fairly old thread, with the last post by the original poster, @Johnson2, occurring on Dec 24, 2020, after joining EP on Dec 6, 2020. I like your links, but presumably @Johnson2 has solved their Stone TFT LCD (which ever model s/he has) interface to Arduino problem. This...
  3. hevans1944

    LDR based relay switching with the help of Very Low Cost, Low Power Microcontroller

    Mass marketing of commercial street lighting should be quite competitive. AFAIK, no one wants to add any unnecessary "bells and whistles" that will increase cost without a specific benefit that reduces cost. The greatest benefit for street lighting would be eliminating the time a streetlight is...
  4. hevans1944

    Advice on linear actuators ? Length of strong strokes per second ?

    Yikes! Vandals with hand-held cans of spray paint aren't good enough? Now you want them able to make high-tech art statements on the sides of random buildings, walls, sidewalks, trucks and vans? Graffiti would never be the same!
  5. hevans1944

    LDR based relay switching with the help of Very Low Cost, Low Power Microcontroller

    @scrollock: There must be more about this "project" than you have revealed so far if the title of your thread, "LDR based relay switching with the help of Very Low Cost, Low Power Microcontroller" is any indication of what you are trying to accomplish with a PIC. I suspect that you want to put...
  6. hevans1944

    Advice on linear actuators ? Length of strong strokes per second ?

    Yeah, I've been thinking about it for a few years now, waiting for technology to advance to the point where I could actually make a successful product either for sale or for me to use. The "magic paintbrush" was shown several times in scenes from "The Expanse" and their concept is much better...
  7. hevans1944

    Advice on linear actuators ? Length of strong strokes per second ?

    Umm. Not what I had in mind. The wiki shows examples of tattoo devices that inject ink under the skin with a needle. What I am looking for is a machine that replaces the hand of the tattoo artist, perhaps using one of the "tattoo machines" shown in the wiki to apply the ink under the control of...
  8. hevans1944

    Advice on linear actuators ? Length of strong strokes per second ?

    There is an art to applying tattoo ink. I was not aware that there is now a machine to apply tattoos. Can anyone provide a link to an image of such a machine? Hollywood often requires certain realistic-appearing tattoos on their actors. Since these actors usually have a real life, somewhere...
  9. hevans1944

    Power Supply Limits? Do & Don't

    A specific example of such a power supply would be helpful, but if the voltage doesn't change under the rated mA load, it makes no difference what the wattage rating of the PS is. Of course no power supply will have a wattage rating less than the product of its maximum voltage and maximum...
  10. hevans1944

    Newbie questions about resistors and measuring voltage and current

    When a 9V battery reaches the end of its chemical charge, there is still enough chemical activity inside to produce a small terminal voltage, although usually much less than nine volts. You can only draw a few micro-amperes of current from it before the internal resistance drops the terminal...
  11. hevans1944

    HC05N

    Some of us here do engage in keeping a thread going, sort of a "conversation" among interested parties sparked by the original poster long after the original poster has disappeared. I just wanted to warn @camila that not all the forum topics are current and there is no "garbage collection" done...
  12. hevans1944

    HC05N

    @camila: this was posted by @Paul o Callaghan waay back in January 19, 2021. It received nine responses from knowledgeable EP members asking for more information. Not one word of response from the OP (original poster). This is typical of the "drive-by poster" who posts a question and then "moves...
  13. hevans1944

    Has anyone ever built one of these?

    The Universe is overflowing with energy. Just look at the number of stars that go nova each year! What a waste of energy that is. Fortunately, all but one of the possible star candidates for nova-hood is located a safe distance from Earth. Our Sun, about 93,000,000 miles away (more or less) is...
  14. hevans1944

    Car battery voltage spikes

    Before attaching your probes to any circuit, make sure the range setting (volts per division) is greater than any anticipated pulse input. If necessary, use a X10 probe to reduce the probe tip voltage to one-tenth of its value before the probe signal is introduced to the oscilloscope. Most...
  15. hevans1944

    Need to build a simple PWM generator

    I will write it for you without charge. See private conversation I started today. Best of luck on finishing the '68 Firebird restoration. I had a brand-new, driven off the showroom floor, 1968 Mercury Cougar that I couldn't afford to keep up. It finally rusted out, parked outside next to my...
  16. hevans1944

    How To Turn Off Or Disable Bluetooth?

    Seems to me you would want to disable Bluetooth capability IN the Appliance. That would prevent the Appliance from being "paired" with ANY Bluetooth remote control. Find the Bluetooth transceiver located inside the Appliance and disable it.
  17. hevans1944

    Need to build a simple PWM generator

    Outstanding idea! Plus, you already know it will work, too! Is this a vintage vehicle that you are trying to restore to its former glory? As for suggesting a PIC solution... that would be the simplest but not the easiest or quickest solution. You can always substitute a PIC solution later, if...
  18. hevans1944

    Need to build a simple PWM generator

    Wow, Jeff! Welcome back to the forums. Looks like you are taking up electronics as a hobby too. I hope your precision machining business is also doing okay. I am totally confused by your duty cycle description. A PWM (pulse width modulated) speed controller for DC motors should produce maximum...
  19. hevans1944

    Hello, Where Does this 2V difference come from in Op-Amps

    It's not necessarily a downside to make mistakes, especially while learning! Most op-amps are dirt cheap. If you accidentally destroy one, and if you can learn from your mistakes, just consider them to be lessons and plug in a replacement. There is a mountain of literature, much of it free to...
  20. hevans1944

    Hello, Where Does this 2V difference come from in Op-Amps

    National Instruments (NI) LabView software is now available for free for non-commercial use by students and hobbyists. It and similar SPICE-based software programs are yet another reason why I prefer actual circuits, made with real components, to software simulations. If money is a problem...
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