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  1. hevans1944

    M.O.S.F.E.T. diode clamp

    In God we Trust, all others pays Cash.
  2. hevans1944

    PWM shielding

    Back in days of old, shielding consisted of braided copper wires woven in a cylinder around the insulated conductors being shielded, quite often just one conductor in which case it was called coaxial cable. Then for low-level instrumentation signals, Belden invented Beldfoil shielding, which...
  3. hevans1944

    Convert Hoverboard to RC remote control

    The cost is what it is. I am sure that most golfers who are either too lazy or too out of shape to haul around their own set of golf clubs will compensate by acquiring boatloads of cash to spend on greens fees, country club memberships, and fancy golf carts. So, if you build it, someone will buy...
  4. hevans1944

    Convert Hoverboard to RC remote control

    The Hype 1 hoverboard uses wheels, not air fans, for weight support. Watch this video. IMHO there are far easier ways to implement an RC cart than "to remove the front wheels of a four wheel utility cart and attach a hoverboard to the front underside." Hows about attaching a pair of RC...
  5. hevans1944

    PWM shielding

    As for connecting the motor shielded cable to your chassis... perhaps the KISS principle applies here. I would use solder lug type barrier terminal strips and attach crimp ring terminals to the external wiring, including the shield and its "drain" wire (if present). That makes it easy to move...
  6. hevans1944

    My new power supply

    Back in the day, its was quite a popular pastime to build a regulated power supply for experimenting with vacuum tube circuits. If you were messing around with power amplifiers, you would also need some negative grid bias, but not much current, for that. And the grid bias voltage should be...
  7. hevans1944

    M.O.S.F.E.T. diode clamp

    Are you designing mosfet wafer dies? There is a huge body of published information, dating back at least fifty years, that pretty much defines all there is know about how to do that. What is your educational background that would prepare you to "study the material side" and what is your goal in...
  8. hevans1944

    Help needed for transmitting 15V signal to 10 metres at 8KB/s using RS232 or RS422 cable

    If by rectifying you mean correcting problems in existing system, that is what we here at Electronics Point have been trying to tell you. But you have not responded with anything useful. In particular, you have not stated whether or not you have an oscilloscope available that you can use to...
  9. hevans1944

    M.O.S.F.E.T. diode clamp

    There is always a diode (one of two body diodes) between the drain and source of every mosfet. There is another body diode between the source and the substrate (body), but it is normally short-circuited by an internal mosfet connection between the source and the substrate, a connection that is...
  10. hevans1944

    What am I looking at?

    Perhaps. Electronics Point might even be the wrong website. Have you tried to find a user group forum for your welder? The cheaper the product, the more it needs a good user group to diagnose and solve problems the manufacturer may choose to ignore. After all, youse paid yer moneys and youse...
  11. hevans1944

    Wind Detecting Circuit

    It finally appeared. The schematic looks to be essentially correct, but what is the purpose of the voltage divider consisting of R3 and R4? Why are there no values associated with any of the parts? What is the transistor part number? What is the op-amp part number? The resistor, R6, in the...
  12. hevans1944

    Wind Detecting Circuit

    Schematic? I don't see whatever you thought you posted. Well, as long as you are having fun and preparing future engineers for work in the real world, you might as well learn something too. A non-inverting op-amp amplifier has a very high input impedance, which is good because you don't want to...
  13. hevans1944

    Wind Detecting Circuit

    Sometime late in the previous century or the early part of this century (I forget exactly when), I purchased a commercial pair with built-in magnets for sensing the passage of steel spokes in a Welch foreline vacuum pump. The outputs were used to re-trigger one-shot multivibrators as each spoke...
  14. hevans1944

    Help needed for transmitting 15V signal to 10 metres at 8KB/s using RS232 or RS422 cable

    Circuit design and programming do NOT have to be perfect. Correct circuit design and correct programming is good enough. There have been many different communication protocols developed since the telegraph was invented. Some, such as serial ASCII, are still being used today because they are...
  15. hevans1944

    Wind Detecting Circuit

    I am pretty sure the lightness of the puff of wind would depend on the bearings used to support the shaft. But why use magnets and a Hall-effect sensor when an opaque slotted disk and an optical interrupter would perform the same function less expensively? You would still need some good bearings...
  16. hevans1944

    Wind Detecting Circuit

    You may want to reconsider your choice of sensor. Although a decent permanent magnet (PM) DC motor will produce an output voltage, which in turn can produce a current in a resistive load, that is more or less a linear function of the motor shaft speed, it may not be the "best" choice based on...
  17. hevans1944

    Battery Insulation resistance Caluculation [Software code ]

    I know that it was difficult for me, first as a pre-teen and later as a teen-ager, to gain any creds of practical experience, no matter how much hobby experience I had accumulated. There was no social media available in which to exchange ideas when I was growing up.This situation didn't really...
  18. hevans1944

    Battery Insulation resistance Caluculation [Software code ]

    AND the linked PDF file shows exactly how to make the required isolation resistance measurements, if you read it carefully all the way to end! Wow! All this confusion has been promulgated by someone who is perhaps English challenged and has a "Master's in Electronic and Electrical Engineering!"...
  19. hevans1944

    Help needed for transmitting 15V signal to 10 metres at 8KB/s using RS232 or RS422 cable

    Seventy bits per second (70B/S) is a very slow (and non-standard) data rate. Even 8000 bits per second (8KB/S) is considered a very slow (and non-standard) data rate. Commonly used baud rates for RS232 are 1200, 2400, 4800, 9600, 19200, 38400, 57600 and 115200 bits per second. All of these are...
  20. hevans1944

    questions anode crt

    I use Viva soft paper towels instead of flannel, and 91% isopropyl alcohol, to clean almost everything electronic. You should make sure the alcohol doesn't dissolve the conductive AcquDAG coating that is sometimes applied to the exterior of the CRT envelope.
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