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  1. hevans1944

    Inverter 12V to 220V

    A decent solar setup providing a few hundred to several thousand watts of power can fry you. Most of these installations use panels wired in series for more voltage. Makes the DC to AC conversion more efficient. Still, even a panel producing "only" 12 V DC, will provide enough energy for a 220 V...
  2. hevans1944

    Centrifuge PCB

    Yet another example of an OP telling us their "solution" rather than explaining what they are trying to DO. For all we know, this could be an example of ball-milling, and the OP wants to observe how the balls pulverize whatever substance is being milled. I think probably not, though, as...
  3. hevans1944

    Question on KVL

    I had to jump ahead in the video to see what you were asking about, but I did watch several minutes of the beginning. That was very painful. Although there were no errors (that I could see) in the subject matter, the voice-over presentation was absolutely awful and downright painful to listen...
  4. hevans1944

    Centrifuge PCB

    You stated your centrifuge spins on an horizontal axis, yet refer to an upper chamber containing electronics and a lower chamber containing ball bearings. Does that mean the centrifuge is spun about a horizontal axis (like the propeller on a boat) and split horizontally into two tandem chambers...
  5. hevans1944

    What good is this for?

    Looks like this is used to charge the photosensitve drum by using an adjacent "corona" wire. Exposure to light then selectively discharges areas on the drum, meaning less toner will stick there. As the drum rotates through the toner it picks up toner on those areas still retaining a charge...
  6. hevans1944

    Building a homemade LCR meter

    Welcome to Electronics Point! Before we get into a long and involved discussion, please tell us about your electronics background and experience. Why do you want to build instead of buy? If you want to be an electronics hobbyist, as most of us who respond to questions here in the Forum are...
  7. hevans1944

    looking for feedback on feasability of this idea...

    I am all for "living green" but have you tried manure and a hot bed? Electronics isn't always the solution.
  8. hevans1944

    Arduino Air flow meter (low speeds)

    It NEVER goes as planned when you get in the field. I have been there many times during a long career. No matter how much you plan, how many contingencies you pack away equipment for, when you get on site there will always be something you wish you had but do not have. So you just make a note of...
  9. hevans1944

    Digital calendar which flashes a LED when out of date range

    @reMARCObil It would help us to help you if you would describe what you are trying to DO instead of describing your solution. A "simple" little box (how big?) that will run on a CR2032 cell (or cells) for one or two years, have a flashing LED, an LCD display, and four buttons is a proposed...
  10. hevans1944

    Does electron die?

    Or, if you have a particularly sensitive and high-resolution voltmeter to measure the capacitor voltage, you might give it ten time-constants to charge to 0.99995 times the charging voltage. For me, most of the time, that's more than enough time to consider the multiplier to be 1.00000 instead...
  11. hevans1944

    Digital calendar which flashes a LED when out of date range

    Agreed. But what kind of cellphone will hold a charge in its battery for one or two years?
  12. hevans1944

    8-Pin Development Board

    Well, with a year more of experience in your bag, please post a revised schematic and I will look it over. Probably want to post a revised circuit board, bottom and top views with the top "silk screened" using your toner transfer technique. Hey! I just realized that I have an ancient copy...
  13. hevans1944

    8-Pin Development Board

    If you remake this board, can you send me one... with the holes already drilled? I found my Dremel drill-press stand, but NONE of my Dremel tools fit it! I won't risk breaking those spiffy carbide drill bits I got from China by not using a drill press. Maybe I can figure out a way to make one of...
  14. hevans1944

    8-Pin Development Board

    Thanks for the link. Yes, I seem to remember reading somewhere that all is good if you use the MPLAB environment, which I do, to program your PICs. But just to be sure I always read that oscillator byte at the last program address, using the PICkit 3, whenever I use a new chip. Then I write the...
  15. hevans1944

    Question about carryover on 4017

    Hmm. I have the same problem posting schematics here in the Forum. I can draw a schematic and photograph it and eventually figure out how to retrieve the image and post it here... but it seems so much simpler to just describe the circuit and let someone else use a schematic-capture program to...
  16. hevans1944

    Digital calendar which flashes a LED when out of date range

    A numeric keypad, such as are used on telephones, is a better HMI (Human-Machine Interface). There are touch-sensitive LCD modules available to hobbyists for use with Arduino microcomputers. The LCD could be programmed to display a keypad and accept command and data inputs from it. Later, after...
  17. hevans1944

    Need help with my project ... Heating

    You have not provided enough information to even begin a design. Does the glass have to remain transparent when it is heated? How is it cooled to 2 C or below? How is such a large sheet of glass supported, and what is its orientation (vertical, horizontal, tilted) with respect to gravity? How...
  18. hevans1944

    Question about carryover on 4017

    Yes, a power-on reset circuit is easily constructed with a resistor, capacitor, small signal diode, and a Schmitt-trigger 2-input NAND gate. Connect resistor and capacitor in series with Vcc to circuit common, place a diode across the resistor for the capacitor to discharge into when Vcc goes to...
  19. hevans1944

    Arduino Air flow meter (low speeds)

    That's a good way to honor one of the Humasol founders. I am so impressed with what your team is accomplishing without the backing of a Monster Mega Corporation. Hopefully we will still be here when you return in the Fall. And I hope the ELC works out for you. Personally, I would have tried much...
  20. hevans1944

    Question about carryover on 4017

    Yes, and how the flip-flops are connected in a ring to circulate a pattern of ones and zeroes. I haven't verified this, but the pattern is supposed to be a Grey Code, which means on each clock transition only one bit in the pattern changes. Not that you should care: the end-user does not have...
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