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  1. hevans1944

    Electronic Circuit error

    How does moving the resistor and the LED "one round lower" change anything? There is still a direct connection from D11, D12, D13, and D14 downward to D15, D16, D17, D18, D19, D20, D21, D22, D23, D24, D25, ... , D46. You have essentially shorted your LED through the transformer and one of the...
  2. hevans1944

    Electronic Circuit error

    You need a "cross" (break in the Vero track) at D15. Or remove all of the trace between D15 and D20 to isolate the ~2 AC power lead from the LED/resistor circuit at D21 and D22.
  3. hevans1944

    help! Unknown prong type!

    This seems to be the crux of the problem, now that the AC versus DC power requirements have been sorted in favor of 12 VAC @ 2A or so current. A simple 2-wire barrel connector is common and readily available in AC "wall wart" transformers. The link is for a 12 VAC @ 3A wall wart transformer from...
  4. hevans1944

    Building a timed motor circuit

    Does the acrylic cover slide horizontally to open and close the wide-mouth part of the funnel? Would a rack-and-pinion mechanism be appropriate for this function? If the cover is allowing something to fall through the funnel when the cover is open, is there any chance it will get jammed when you...
  5. hevans1944

    Choosing a 32 Bit MCU

    As a non-professional programmer, I started out in the 1970s using Intel 8-bit microprocessors for embedded applications, programming them in assembly. As the years went by, and the personal computer took over the microprocessor market, the internals of the microprocessor became pretty much...
  6. hevans1944

    fluctuating magnetic field generator design

    It now appears you are mistakenly seeking information in an open and public forum for a proprietary industrial solution to some problem for which you feel you are not at liberty to provide any useful description. Why should anyone here on Electronics Point be willing to "help" you? I agree with...
  7. hevans1944

    Li-ion battery pack

    We were recently gifted with an ancient Roomba iRobot vacuum cleaner. Unfortunately, it's NiCd battery or NiMH battery (not sure which, but definitely not Li-ion chemistry) will not accept or hold a charge, nor did we receive the wall-wart charger that went with the original unit. Newly...
  8. hevans1944

    fluctuating magnetic field generator design

    Would you be able to answer some simple questions, like WTF are you trying to DO? @duke37 mentioned You earlier asked @duke37 responded with a list, suggesting all this might fit on a smallish circuit board. You have not said what components (very small) must be less than 1mm in size, nor...
  9. hevans1944

    For Sale: Sony Trinitron KV-25XBRII

    I remember purchasing an over-priced Magnavox console color TV in the 1960s, complete with a complement of about twenty or so vacuum tubes and a humongous shadow-mask CRT. Then for the next ten years or so, I tried to keep it running by replacing various "valves" as their filaments failed, or...
  10. hevans1944

    Unknown capacitor.

    As @Tha fios agaibh mentioned in his post #62... Methinks the problem was solved much earlier in this thread with the discovery that the zener diode had shorted, the remaining questions being (1) why? (2) what voltage was it? (3) was the wattage rating too small? Once the postman cometh, and a...
  11. hevans1944

    Unable to get solenoid controlled by Arduino to work anymore

    It is likely that you have either wired the transistor incorrectly or have damaged it by wiring it incorrectly. You should be able to turn the transistor on, thereby actuating the solenoid valve, by connecting its base current-limiting resistor to +5 VDC derived from the voltage regulator on...
  12. hevans1944

    Unknown capacitor.

    Yup. Put that right up there with not tuggin' on Superman's cape or pullin' the mask off the old Lone Ranger...
  13. hevans1944

    Unknown capacitor.

    Is there any correlation between the value measured for this capacitor and the markings printed on it?
  14. hevans1944

    Unknown capacitor.

    Magnification was fine. The picture was out of focus in the lettering plane of the capacitor. Note that everything else in the image is sharp and clear, thanks to the auto-focus POS software your camera uses. Here is a better idea: get a largeish sheet of white paper and cut out a rectangular...
  15. hevans1944

    Unknown capacitor.

    Nothing. I'm convinced that the zener diode is shorted and should be replaced with one of the same voltage but higher wattage rating. After replacing the zener diode, make sure the diode bridge is actually working. There may be one or more diodes open or shorted in the bridge rectifier. Surely...
  16. hevans1944

    Modifying a battery powered light to hardwired.

    I like to qualify my answers with weasel words like "maybe," "probably," and "your mileage (or kilometers) may vary" because no one here can be responsible for what original posters do, or how they do it, with the answers we provide. This is a hobby forum. You are responsible for your own...
  17. hevans1944

    Unknown capacitor.

    I suppose it could be internally open. Maybe substitute a known "good" one? Lots of itsy bitsy teeny weeny 3-terminal devices on the "bottom" side of the board, but what is controlling power to the punch solenoid(s)? Would that be the black 3-terminal thingy at the top left (opposite U2)? And...
  18. hevans1944

    Modifying a battery powered light to hardwired.

    You didn't say what the rated voltage and current for your motion-sensitive light is. Four alkaline chemistry AA cells provide 6 V DC when fresh. The current available from AA cells is typically less than one ampere, so if your AC to DC power supply is a "wall wart" delivering 6 V DC at no more...
  19. hevans1944

    Unknown capacitor.

    Jeez.... is this another one of those power supplies that uses capacitive reactance to drop line voltage to a lower value? The cap in the photo "looks" okay. Does it have any measurable conductance when measured "out of circuit" and removed from the board? I doubt that its capacitance could...
  20. hevans1944

    do parallel connected leds consume more power?

    Each LED will consume an amount of power equal to its forward voltage drop at whatever current is passing through the LED. If you connect LEDs in parallel, there is no way to guarantee that each will have the same forward voltage drop, nor that the current will distribute equally across all the...
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