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  1. duke37

    Name them Parts

    3 may be an ultrasonic distance measurer.
  2. duke37

    DC voltage blocker - Blocking AC too?

    I have two versions of the Art of electronics. One review suggested that the main requirement was a strong table, I do not use the latest version but often refer to the previous one which may be a reasonable price second hand,
  3. duke37

    IR and seeing it...

    A verticle beam will go out to space. In order to see it, it will need to be reflected by something. Clouds may do or may attenuate the signal below detection level. A barrage baloon with reflective coating should work.
  4. duke37

    Ceiling Fan Capacitor Question

    What is 5% less then 4.8μF ?
  5. duke37

    Diode Help

    If the diode is equivalent to a 1N4005, then I would suggest getting 1N4007 which is a 1000V diode. Why did the original diode fail? Too high a voltage?
  6. duke37

    I have a Sa-HE200 and it powers up but no sound from speakers after overload kicked couple times.

    Fire it up through a lamp limiter so that voltages and currents can be measured without blowing fuses.
  7. duke37

    Connecting non-solderable wires

    Silver solder needs a blow torch to get sufficient temperature. I wonder how the cost compares with a mechanical connector.
  8. duke37

    A Stretch

    Make sure the centre pin goes to the correct place. If the other two connections are the wrong way round. then the kob will operate in the wrong direction. Just swap them over.
  9. duke37

    Connecting non-solderable wires

    If the resistance wire gets hot, then tin/lead solder would probably fail. Electric elements are often spot welded. You could use Easyflow for the entire connection.
  10. duke37

    Millermatic 30E dynamic braking question

    There is an SCR which i think would be switched on to brake. Check this. My eyes are too dim to read the device values.
  11. duke37

    Voltage Regulation

    It is often said that a fuse only protects the cable, not the device. You do not want 40A to be fed through a thin cable. Look at each device and fuse to somewhat larger then the demand. I would venture to suggest that 1A would be enough for most pieces of equipment. A scrap fuse array out of a...
  12. duke37

    Voltage Regulation

    A 40A fuse should protect the 40A power supply. No fuse will protect the drven devices, they will take what current they like. A fuse in each supply will help if the device is faulty. 12V at 40A is plenty to start a fire. Fuses do not limit current unless they blow. A 12V bulb can be used as a...
  13. duke37

    A Stretch

    The 500k pot is used as a variable resistance and the higher the resistance, the higher the gain If you replace with 100k then the maximum gain will be reduced by a factor of 5 but this may be enough, depending on the input signal level.
  14. duke37

    A Stretch

    And connect the +ve side of C3 to the op amp output.
  15. duke37

    Transistor series voltage regulator

    Such a regulator will not increase or decrease the voltage. it is intended to maintain a constant voltage and will only change a little when the load is changed. To change the voltage, the transistor can be driven through a potentiometer or the zener can be changed for one with a different...
  16. duke37

    Transistor series voltage regulator

    Rs passes a current which generates a voltage across the zener diode. This can be used as a voltage regulator on its own but if too much current is taken by the load, then no current will pass through the zener and the voltage will drop. Adding a transistor means that only base current loads the...
  17. duke37

    Cost efficient pipe inspection solution

    Looks as if the electrical leak method has already been used in ponds. You will need a sufficient current if there is a leak to generate a potential gradiant in the ground. Some experiment would be necessary to find the current to give sufficient sensitivity - perhaps a few amps. You do not...
  18. duke37

    Cost efficient pipe inspection solution

    You do not say what the pipe is transporting. If it is a conductive liquid you could fill the pipe and electrically isolate the ends and measure the resistance to earth. If there is a leak, then the soil locally will be at a different voltage. Polyethylene is a good insulator and a Megger could...
  19. duke37

    Triple output power supply blowing main fuse

    A 300W bulb is perhaps excessive, I use a 40W bulb to check old valved radios or transistor amps. Looks as if the GBU810 is the mains rectifier which feeds the 450V capacitors. Check the resistance across the four diodes both ways in the rectifier. A dead diode would likely be a short. I wpuld...
  20. duke37

    speaker dc jack repair

    Describe with pictures axactly what was done. It sounds as if you have connected the speaker to 12V DC and melted it. Measure the resistance across the speaker plug. If it is open circuit you may be lucky and have a blown fuse.
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