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  1. hevans1944

    Toggle Switch Covers

    If you have the patience for it, you can buy at many hardware stores a can of red plastic "stuff" used to coat tool handles to provide a better grip. Just dip the toggle switch handles in it and suspend over a drip catcher (like newspapers) for 24 hours. Repeat if necessary until you get the...
  2. hevans1944

    DRSSTC: Dual Resonant Solid State Tesla Coil

    Nice to see photos from someone who really knows how to build Tesla Coils! Is the top-loading toroid capacitance "hat" constructed from flexible aluminum duct tubing? How is this supported in its interior? Wood? Plastic?
  3. hevans1944

    disconnect switches

    If by "kill switch" you mean to interrupt a 16 kV circuit with current flowing through the switch, there are people and companies who know how to safely do this, and switches are made for just this purpose. If you need to ask the question here, you are unqualified to work on this type of...
  4. hevans1944

    motion sensor using timer

    Wow! Yet another near-field hand-waving detector! Is there no limit to the versatility of the ubiquitous 555 integrated circuit? Not just an IC, it's a career! Ummm... and you want to get rid of it? Why?
  5. hevans1944

    Need help designing 200 volt power supply.

    Where is the rest of the circuit diagram? Please upload a link to the site you obtained this from. Good luck finding an 800 volt, 500 microfarad, capacitor. Those were large even for professional xenon flash illuminators used in photography. Very dangerous, too, when charged. Please try to...
  6. hevans1944

    Simple Photodiode Reverse Bias Circuit - Current?

    Your diagram shows the photodiode with forward bias, which is incorrect. Photodiodes are always reverse-biased when used as light sensors. OTOH, if this is a power-producing photocell, disregard the discussion below. What is your question? What is VO? Where is the piece-wise linear...
  7. hevans1944

    For Sale: 45 year collection of parts for sale

    You should have rented a space in the Flea Market at the Dayton Hamvention® to be held later this month (May 15, 16, and 17) and hauled it all down. More than 20,000 hams will be there, ready to dole out cash for real bargains on obsolete junk and not-so-obsolete hard-to-find goodies. Do you...
  8. hevans1944

    Home Security Cameras System

    Q-See claims to have "weatherproof" cameras for outdoor use, but caveat emptor on that. It is difficult to make a camera "weatherproof" and keep it competitively priced. The outdoor weatherproof dome enclosure for my Toshiba camera costs almost as much as the camera itself. It does, however...
  9. hevans1944

    Home Security Cameras System

    Analog cameras (NTSC analog video) are virtually obsolete and mostly unobtainable, especially in resolutions sufficient for security purposes. I have one that I installed in my detached garage several years ago. It uses a wireless RF analog link to a special receiver in the house. The receiver...
  10. hevans1944

    Why are Anritsu manuals so hard to locate?

    All I could find was a PDF blurb from Anritsu for the ML424A and an Anritsu web page for the discontinued MG442A. Maybe whoever sells these devices would sell a few copies of the spec sheet from the manual (if they have the manual). Appears to be very high quality professional test equipment.
  11. hevans1944

    treadmill display is blinking

    Why chicken cross the road? Maybe to see what treadmill you have? You read the operating manual yet? Blinky light to attract your attention. Up to you to decide what problem.
  12. hevans1944

    Home Security Cameras System

    No effective bandwidth limitations I can see on the LAN, but connecting to the Internet via cell phone slows things way down. I only could afford the one camera. I've never tested to see if anything else on the LAN is affected by streaming from the camera. If that turned out to be the case, I...
  13. hevans1944

    Home Security Cameras System

    I use a Toshiba Model No. IK-WB16A. It connects to a wired port on my local area network (LAN) router and can be viewed on any PC in the house that is also connected to the LAN. With the right software I can view "real-time" images on my cell phone. It has very good resolution (1600 x 1200...
  14. hevans1944

    Microcontroller controlled by pushbutton for LED flashlight

    Ummm? Go for what? The implant surgery went off without a hitch. I am not allowed to raise my left arm above my shoulder for six weeks, and it feels like someone punched me real hard where the defibrillator/pacemaker is located, but other than that I am okay. Blew up my second PIC10F206 while...
  15. hevans1944

    Microcontroller controlled by pushbutton for LED flashlight

    @Arouse1973 does this mean you are satisfied with your firmware now? Perhaps @TenderTendon can machine a board on his CNC mill. The vias can be filled with small wires and soldered to both sides of the board for prototyping purposes. I don't think it wise to make 51 PCBs until Jeff has at least...
  16. hevans1944

    Water Level Sensor

    Disconnect this device and connect a continuity tester (ohmmeter) across the two leads. Bring one pole of a strong magnet, such as a rare-earth neodymium magnet very near the bottom plastic case. If the circuit closes (or opens) there is a reed relay inside and it is probably a water level...
  17. hevans1944

    Controller boards for multiple relays

    You consider this module fancy? Why? What does it do that you don't think you need it to do? Maybe you should draw up a design specification and contract to have your board made. Surely you aren't getting any "help" from anyone on this forum.
  18. hevans1944

    Hearing Aid Design

    If you think you can couple audio signals to a hearing aid telecoil from an inductive loop worn around the neck, go for it. Please post to the forum how that worked out for you.
  19. hevans1944

    Hearing Aid Design

    The miniTek DOES NOT connect to the hearing aid via Bluetooth. There is no Bluetooth transceiver in the hearing aid because it would be too big. The Bluetooth transceiver is in the miniTek. The miniTek uses a proprietary near-field analog FM communication technology to send audio to the hearing...
  20. hevans1944

    Trying to find type/name/replacement cord

    I don't know how they get 70 watts from 12 V @ 0.95 A because that is a tad more than 11 watts. OTOH, 70 watts sounds about right for a Peltier solid-state cooler with three little fans. So, I am guessing this thing was designed to plug into a cigarette lighter on an automobile and get 12 V DC...
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