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  1. hevans1944

    Strange part

    Of course they don't. Why pass up the opportunity to sell a €2000 Chinese-manufactured circuit board instead of a €2 high-voltage, thick-film, resistor? And then there is the CYA medical liability issue to consider... what if, in attempting to repair this POS import, you cause it to operate in a...
  2. hevans1944

    LED in distilled water?

    Triple-distilled water has very low conductivity, but it won't stay that way once it is placed in contact with real-world devices and plumbing. The water molecule is highly polarized and will react with damned near everything to create a conductive ion solution. This may happen later rather than...
  3. hevans1944

    Component ID.

    Agreed. Try this link if you need to purchase one.
  4. hevans1944

    How to connect LED strip to batteries

    Make sure you cut the strip at the right places. The cutting places should be clearly marked on the strip. Generally, three LEDs (minimum) or an integer (whole number) multiple of the minimum number is required for each strip cut from the reel. The two outer edges of the strip carry 12 V DC...
  5. hevans1944

    How to connect LED strip to batteries

    @jesse salinas: I think you may have finally "got it". Good point that Harald made in his post #14 about the push-button switch. Make sure it can handle at least two amperes of current. As for the battery... if you are gonna be carrying this around, a belt that holds eight D-size cells, either...
  6. hevans1944

    How to connect LED strip to batteries

    The 3M strips likely require more than the 3 V available from two D-cells. Try increasing to four cells (6 V) or six cells (9V) or even eight cells (12 V), all connected in series-aiding (so the voltages add up). What is the part or model number of the 3M strips you are trying to use? Do you...
  7. hevans1944

    Rodin Coil 3 Input Oscillator

    Rodin coils, eh? As in this nutbag Marko Rodin? We don't do woo-woo "science" here. What do you expect to accomplish with your "induction coils," and how does winding them with "small gauge wire" on "very small" plastic forms you are calling stators, produced by a 3D printer, accomplish...
  8. hevans1944

    Retail product that can supply 120V/30A from battery?

    Your intuition about starting batteries is correct, just the scale is wrong. A few hundred amperes for ten or twenty seconds to start a car engine isn't a lot of ampere-hours, and 3600 watts at 12 V DC is only about 300 A... plus a little more to allow for inefficiencies... but, you said it...
  9. hevans1944

    My electromagnetic pulse generator

    Yes, I agree with your observation that distance diminishes the effects. The radiation from our Sun is not just heat and light. The solar wind is real, high-energy particles, that can do considerable damage to unprotected objects, Fortunately, the Earth's magnetic field deflects most of the...
  10. hevans1944

    Retail product that can supply 120V/30A from battery?

    Yep. You have to pay to play in this arena. 3600 watts for two or three minutes may not sound like much, but a battery-powered inverter drawing perhaps 5000 watts (to allow for conversion losses and other inefficiencies), powered from a bank of ten series-connected 12 V DC lead-acid storage...
  11. hevans1944

    Motion sensor timing

    @(*steve*), thanks for that post. Another person that I respect here PMed me with the admonishment that my first reply to this thread was condescending. Looking back on it, probably so, and I hereby apologize to @Katie Davidson Smith for that. Frustration is no excuse for a lack of temperance in...
  12. hevans1944

    Motion sensor timing

    Not condescending at all. Here at Electronics Point we get a LOT of "drive by" posters looking for a quick answer to their problem. That isn't what EP is about. This is a discussion forum for folks with a genuine interest in electronics, whether a rank beginner who knows almost nothing about the...
  13. hevans1944

    Motion sensor timing

    So why would you choose a project requiring "electrics" of which you don't know much about? Why? How is this "better" than using an ordinary manually-operated toggle or rotary or push-button switch? Have you seen a device marketed as "The Clapper" which turns a light on or off at the clap of...
  14. hevans1944

    i need to find those variable capacitor

    Have you met Google? Try here.
  15. hevans1944

    One wire light bulb?

    Have you made friends with Google yet? Here is the result of using this search string: "47k ohm resistor". However, based on your responses so far, it is clearly too dangerous for you to be messin' around with mains voltages at this time. You are safely insulated from the voltages that are used...
  16. hevans1944

    One wire light bulb?

    This is probably a neon lamp. It may or may not have a current-limiting resistor inside. Neon lamps always require a current limiting resistance when connected to a low-impedance voltage source, which is what mains wiring is. If the lamp does have such a resistor, you can usually connect the two...
  17. hevans1944

    Strange symbols in Cct. Diags.

    Okay, while we are tredging the ancient nostalgia trail, I remember when it was mmfd (verbally mickey-mikes) instead of μμFd and then (much later) pFd which was of course shortened verbally to "puff". Often Fd was shortened to just F or f as there is no other common unit of measurement, AFAIK...
  18. hevans1944

    Strange symbols in Cct. Diags.

    The hash lines between the two plates is apparently the Japanese way of symbolizing a polarized electrolytic capacitor, See diagram below, which is the result of this Google search.
  19. hevans1944

    Identifying a chip

    That's really unfortunate, but given the secretive practices of the board manufacturer, your only alternative may be to send the board back to them for repair. Have you made any inquiries with this company to find out how much they would charge to repair or replace this interface control board...
  20. hevans1944

    My electromagnetic pulse generator

    None of the research and development in the past sixty or so years (since WWII) has yielded a practical EMP weapon, suitable for deployment on the battlefield. There have been many attempts to build one-time-use-only, as well as re-loadable, EMP generators that could possibly prove useful in...
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