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  1. hevans1944

    Hi Everyone from Calgary

    @CalgaryPT : Welcome to Electronics Point! You and I appear to have similar backgrounds. I, too, was afraid to mess with SMD because it looked really difficult. But a couple of years ago I took the plunge and ordered some really fine (0.021" diameter) 63/37 flux-core eutectic tin-lead solder...
  2. hevans1944

    Photo sensitive circuit

    The circuit your friend provided is overkill for what you are trying to do: turn on the strobe light if the drone navigation light(s) illuminate the LDR. However it should work as well as your original circuit. The strobe light should be connected to the NO contacts instead of the NC contacts...
  3. hevans1944

    to hire someone who knows s/w turn ckt-diag into PCB Gerber fabrication files

    Here is a blog post comparing Eagle and Kicad. Seeed Studio is a reliable Chinese PCB manufacturer plus a whole lot more, with tools and modules aimed squarely at the hobbyist. Some Seeed modules are (or were) stocked by Radio Shack. As per usual when dealing with Asian vendors, documentation...
  4. hevans1944

    Photo sensitive circuit

    Excellent idea. The relay will provide reliable on/off operation of the lamp. Perhaps you should consider replacing the lamp with a relay having a set of Form C contacts and a 6V DC coil. Use the normally-open contacts to connect the lamp to a voltage source, turning the lamp on when the relay...
  5. hevans1944

    to hire someone who knows s/w turn ckt-diag into PCB Gerber fabrication files

    PCB "engraving" machines have been around for quite some time... some of them even work... sort of. You have to be aware of their limitations with regard to resolution and accuracy. For any PCB of significant size and/or complexity, removing copper by scraping or machining is going to be a...
  6. hevans1944

    to hire someone who knows s/w turn ckt-diag into PCB Gerber fabrication files

    Have you acquired any PCB software yet? If so, please tell us what you have. As @Minder mentioned, there is free PCB design software available. Avoid PCB houses that offer you their "free" schematic capture and layout software because the files their software creates are not portable Gerber...
  7. hevans1944

    to hire someone who knows s/w turn ckt-diag into PCB Gerber fabrication files

    What you are asking does not come cheap. Try looking at the companies represented here to find someone with the capabilities you need. For a shop in Aurora, Colorado, visit this web page. As Steve said, there are many of us here that can do what you want to do, from scanning a printed circuit...
  8. hevans1944

    EST Quickstart

    My wife does telephone solicitations/reminders for local classes offered nationwide by NTC (National Training Center) for technicians studying for NICET (National Institute for Certification in Engineering Technologies) certification levels 1, 2, 3, and 4. Many states accept NICET certification...
  9. hevans1944

    Short Wave Radio Project Help Needed

    Please provide a full description of where you got this page: name of book or magazine, date of publication, volume number, etc.
  10. hevans1944

    Negative Voltage

    Yes, I remember from my Novice year as a newly-minted amateur radio operator, building a crystal-controlled oscillator driving the ubiquitous RCA 6146B beam power pentode, that I absolutely needed to connect the cathode to chassis ground (which was, hopefully, also RF ground). I was running the...
  11. hevans1944

    Negative Voltage

    Absolutely correct! It looks like you understand potential difference after all, positive as well as negative. For the Fender amp, the center-tap on the secondary of the power transformer is the 0V reference for the rectified and filtered DC. You should note on the schematic that this is...
  12. hevans1944

    Resiter Divider / Resister Watt ratings

    Since you are measuring the output of a solar panel, you will have plenty of current to run a voltage divider. The main question is how much current does the Arduino A/D converter require at its input? The DC input impedance is very high, but there are other considerations associated with the...
  13. hevans1944

    Negative Voltage

    Mmmm, A positive battery or a negative battery, eh? I have never heard of batteries having the characteristic of being positive or negative. Batteries are all just little containers of electro-chemical energy with a positive pole and a negative pole, the poles always coming in pairs. Similar to...
  14. hevans1944

    Negative Voltage

    It isn't a contest. If you truly understand the concept of negative numbers, then positive and negative voltages should make sense as well. Many years ago while attending grammar school I recall being introduced to negative numbers. We had already been introduced to positive integers by the...
  15. hevans1944

    Negative Voltage

    This is essentially correct, although I would question your use of the word higher when you probably should use the words more positive. Everyone knows what high voltage means... sufficient voltage to cause grievous harm to people or equipment... but the adjective "high" simply refers to...
  16. hevans1944

    Amplifier Potentiometer Replacement

    Ha! A few years ago my wife's youngest son formed a garage band in (where else?) my detached garage. They couldn't afford much in the way of guitars, or amps, or speakers, or effects boxes (stomp boxes) etc. So they settled for LOUD. I must confess that I didn't really appreciate their efforts...
  17. hevans1944

    Embedded system detailed design steps

    Google is your best friend to get ya started on this quest. But realize that each embedded system design is unique to its particular application. Their are no "cookie cutter" formulas or short-cuts to learning system design. A four-year engineering school curriculum, followed after graduation by...
  18. hevans1944

    Amplifier Potentiometer Replacement

    Good job! I am not sure why there even is "OUTPUT POWER" control unless it's possibly to protect speakers with lower wattage capabilities.
  19. hevans1944

    Controlling a 28byj-48 stepper motor with picaxe 28x2 chip

    Is the code snippet below anything like what you are trying to work with? let dirsB = %00001111 ; make pins output main: for b3 = 0 to 99 ; start a for...next loop gosub lstep ; call left step sub-procedure next b3 ...
  20. hevans1944

    Amplifier Potentiometer Replacement

    Functional is good. However, rotary wafer switches with twelve positions are common. Many have mechanical stops that can be positioned to select from two to eleven positions, or if continuous rotation is desired, twelve positions. It should be a relatively trivial exercise to solder ten fixed...
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