Search results

Search Forums New Posts
  1. hevans1944

    Help amplifying a tiny current

    That is a fair choice. It's rated to operate with 4 V to 6 V DC, so 3V is a little on the iffy side. Can you provide your temperature sensing board with more than 3 V DC? Say, three AA cells in series for 4.5 V DC? It should tolerate that. The input impedance of the SSR is a little on the low...
  2. hevans1944

    could someone please identify this component for me?

    Oops. Fixed it.
  3. hevans1944

    electromagnetism

    An electromagnet, any size, uses a ferromagnetic material (soft iron or silicon transformer steel or ceramic ferrites) for the core and an open (air gap) magnetic circuit path. Wire is wound around the core to create the magnetic field produced by the electromagnet. The core intensifies and...
  4. hevans1944

    could someone please identify this component for me?

    They appear to be 0.1 μF and 0.33 μF, respectively, metalized plastic-film capacitors. Plastic film can be a lot of things, but Mylar and polypropylene are common, as @davenn stated. There are dozens of others. At the capacitance given, definitely not mica... too small in size and mica is...
  5. hevans1944

    Hitachi V-1065A oscilloscope...

    You need a digital storage oscilloscope (DSO) with sufficient memory depth to record however many characters you need to "see" at 9600 baud. If the data is serial ASCII, it typically consists of ten or eleven bits per character: start bit, eight data bits, one or two stop bits. If just one stop...
  6. hevans1944

    Help with invention

    Actually, it was @Alec_t in post #3 who linked to a cellphone app and to a Google glass patent for speech-to-text app. There is almost no information on what the Google patent covers, but I doubt it preempts or predates the cellphone app. Surely the lawyers will duke it out eventually. That...
  7. hevans1944

    Water as a conductor?

    This is how I keep the brain cells from atrophying as I get older. Remembering things and solving puzzles (like why do I spend so much time here on EP) is supposed to aid in retaining higher brain functions, but maybe that isn't working for me. Ask Steven Hawking about that, although I hear from...
  8. hevans1944

    Water as a conductor?

    Hurricane Hermine this week convinced me that living on a boat is not a good idea. My step-daughter, who lives in a house on more or less dry land in Virginia Beach, VA, is getting pounded by the remnants of this now-tropical storm as I write this. And soon they will be pounded with snow as...
  9. hevans1944

    Help with invention

    Yeah, you N. FL. guys are all wet right now.:D Chris, I am "busy" biting my nails to the bone trying to figure out how to line up all the ducks I need to line up and kill before closing on October 20, 2016. Inspections, surveys, title searches, insurance... the list seems endless... and feels...
  10. hevans1944

    Water as a conductor?

    This is a specific implementation of a general optical concept called frustrated total internal reflection (FTIR). You can demonstrate the concept easily using an ordinary prism with a flat bottom and two sides that are at 45 degree angles to the bottom. Shine a laser pointer into the prism...
  11. hevans1944

    How to Interface to PT4303-S Superhet Receiver Chip

    Someone posting as @PTaylor hijacked another thread on this subject, after surmising they should have opened a new thread. So, I am doing just that. Below is the original post followed by my comments: This popular Asian chip is used to receive amplitude shift keyed (ASK) or On/Off Keyed (OOK)...
  12. hevans1944

    Water as a conductor?

    If all you want to do is sense presence of water at some level, try this:
  13. hevans1944

    Audio amplifier to amplify a load cell signal

    Yep. That's the way it's usually done... unless the load cell and signal conditioning wiring is so poorly done that induced "hum" from the ever-present electromagnetic field produced by power-line wiring overwhelms the front-end of the instrumentation amplifier. Even operating from batteries to...
  14. hevans1944

    Audio amplifier to amplify a load cell signal

    Before embarking on this quest, you should endeavor to learn where your noise originates and what kind of noise it is. Load cells are traditionally excited with DC (usually 10 V DC), and there is a huge reservoir of theory and application examples you should tap into before even attempting to...
  15. hevans1944

    Help with invention

    I have often wondered how apps for cellphones get written. Anybody got any clues on how to do that? I am too busy to Google it and chase down leads right now.
  16. hevans1944

    Modified pocket calculator

    Have you actually thought about studying for the exam instead of loading a "calculator" with crib notes? There are some very nice high-tech solutions that can give you an advantage in taking exams, but the best of these require a confederate and surreptitious two-way communications, preferable...
  17. hevans1944

    Help with invention

    If you do decide to proceed with this, an LED display such as you proposed is not very user-friendly for alphanumeric display of speech. It is also very power-hungry. A liquid-crystal display (LCD) with a user-controlled backlight would be better. The only advantage of an LED display is the...
  18. hevans1944

    Modified pocket calculator

    Hmm. Sounds to me you seek to obtain an unfair advantage over others taking the same exam.
  19. hevans1944

    Can you identify this lifeform?

    Michael Jackson has returned!
  20. hevans1944

    Tube Light working Explained

    Have you looked at any of the links on this Google results page? In particular, have you read and understood the Wikipedia explanation? You like pretty pictures and animation? Try this You Tube video explanation. All this, and more, can be found on the first link I posted, along with more than...
Top