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  1. hevans1944

    8 Bit or 32 Bit Microcontroller

    I think the interviewer is trying to determine whether or not you know anything about microprocessors. The answer is probably NOT "This processor is better because... yada, yada, yada." They are probably looking for an answer that describes the in-depth considerations you would make before...
  2. hevans1944

    8,16,32 bit controllers

    If you download the datasheets for 8, 16, and 32 bit controllers and read those datasheets, you will get the answer to your question.
  3. hevans1944

    DC Motor drive

    You could check with this company.
  4. hevans1944

    Designing a Time Delayed Relay

    Lessee... 20 A corresponds to a voltage of 4.5 V and -20 A corresponds to a voltage of 0,5 V. So, you can write a linear equation for any output voltage a function of input current: Vout = 2.5 V + (4/40) (Iin). For Iin = 2,5 that means Vout = 2.5 + 0.1 (2.5) = 2.75 V. Check. For Iin = 4 A that...
  5. hevans1944

    Optocoupler

    Even if the BC547 transistor collector were not wired to a pin that is not connected (NC) on the datasheet, the most this obsolete optocoupler would do is turn the triac on or off. No dimming effect will occur without some sort of phase control of the input pulse with respect to the AC power...
  6. hevans1944

    Was, Were, Wasn't and Weren't

    u tnk?
  7. hevans1944

    Designing a Time Delayed Relay

    The hardware was essentially complete as of January 3, 2015. John has been learning how to program PICs since then. I offered to do the programming, but he refused to accept my offer. How is the man going to learn anything if someone else hands him a canned solution? IMHO, it was a good decision...
  8. hevans1944

    How to build a 455khz oscillator for a signal generator..

    If you don't mind spending fifty bux, maybe this sweep generator from China will do the job. You don't simply "peak up" the interstage IF transformers, you stagger tune them to provide the receiver bandwidth you need for good selectivity and audio quality. To do this, you need a sweep generator...
  9. hevans1944

    Charging a tuned L/C circuit

    That's a function of matching impedances for maximum power transfer. Not usually something you can easily do at 105.1 Megahertz. An L/C combination resonant at that frequency is very tiny... a few picofarads of capacitance and a few turns of wire on the coil. Good luck trying to couple...
  10. hevans1944

    Charging a tuned L/C circuit

    It all depends on the area of your antenna that intercepts the transmitted radiation. Bigger and closer to the source of radiation is better.
  11. hevans1944

    Was, Were, Wasn't and Weren't

    Hey! Hows come @Ratch hasn't weighed in on this? He's self-admittedly hopelessly pedantic. And on trees for paper... why not? You can plant and re-grow trees, and trees put oxygen back in the atmosphere. What about all those zillions of tons of plastic bags now used in grocery stores in lieu of...
  12. hevans1944

    New guy... Equipment choices... Practice Boards.

    That's a pretty nice kit you found. About the only thing I would add is an Edsyn vacuum-pump Soldapullt hand tool for use in conjunction with solder wick. A small spool of solder wick comes in your kit, but you may want to purchase other sizes. The Edsyn vacuum tool is easy to clean and useful...
  13. hevans1944

    Charging a tuned L/C circuit

    I do not know what an inducer might be, nor is the quoted sentence an actual question, although it does begin with the interrogative phrase, "Could anyone provide me..." Electronics is an exact science and the spelling and meaning of words are critical to understanding. Is it possible that you...
  14. hevans1944

    Designing a Time Delayed Relay

    Chris, the thread is getting a bit long in the tooth, but it is an interesting chronicle of the journey John has made from newbie to accomplished PIC artist. @KrisBlueNZ provided lots of guidance and feedback before he passed, but John took it to completion by designing and populating a...
  15. hevans1944

    Partially shaded solar panels

    And save even more money by using a 1-wire extension cord. :eek:
  16. hevans1944

    Controlling a shower pump

    When I bought this house thirty-something years ago, the tiny gas-fired water heater failed shortly afterwards. Two replacements since then have been huge 50+ gallon tanks with the temperature turned up high enough to guarantee continuous hot shower water for almost an hour. That was necessary...
  17. hevans1944

    Designing a Time Delayed Relay

    Something about your max and min routine doesn't look right. On the first iteration you should compare max against a value greater than, or equal to, half of full-scale and compare min against a value less than, or equal to, half of full-scale. Since this is an un-signed ten-bit integer from the...
  18. hevans1944

    Partially shaded solar panels

    Bob, your prospective solar panels simply need more elevation to place them above the shade of the trees. I could recommend suspending them with one or more tethered hot-air balloons, inflated by the solar panel salesman's breath, but this may not be cost-effective. You would probably have to...
  19. hevans1944

    looking for this flex wire to PCB socket

    Welcome to Electronics Point, @DirtinLa! We really LOVE it when the original poster (OP) solves their problem(s) without our help! :D And I love a twenty-one cent solution. Good job! :cool: Please visit us often.
  20. hevans1944

    Help! plz making an amplifier board

    Well, here's a schematic from the vendor's website: There should be two of these circuits on the circuit board since this is supposed to be a 50 watt stereo amplifier. My guess (since one of the ICs runs hot) is a shorted electrolytic capacitor, perhaps C9 or C12. Since it's a kit, check to...
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