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  1. duke37

    What is the difference or similarity between these 2 pot circuits?

    "as far as replacing the 500k pcb pot, I am going from a multi turn pot to a 270 degree 500k pot (for coarse adjustment), I need the circuit board to see a total of only 500k, across the pots. Wouldn't the board if wired in the top photo see a total of 550k??" I should not think that 550kΩ will...
  2. duke37

    Homemade capacitors, that hold a charge?

    Nitpick 3: K is a unit of temperature. Kg should be kg
  3. duke37

    What is the difference or similarity between these 2 pot circuits?

    I would have gone for the top circuit, it only has two connections which is what you want. If you have three connections, what do they do? If replacing a 500kΩ pot, then a 500Ω pot will do very lttle.:)
  4. duke37

    Caustic Corrosion on Water Level Sensor

    An alternative is to use an ultrasonic distance measuring device. I bought a couple of these some time ago but have not had the time to investigate if they work and how to decode the output.
  5. duke37

    Electronics AutoVolt Common problem. HELP

    There is no fault, the device is designed for 220V and 110V is just not enough.
  6. duke37

    12v In A Bathroom

    It is rubbish. The power is 50W, hours should not be stated and only confuses things . A watt is 1J/s so 1W for 1sec = 1J. A joule is a very small energy unit so energy is often sold in amounts of 3.6MJ or 1kWh. Oh dear, I think I am confusing things. In the UK electrical work in a bathroom...
  7. duke37

    12v In A Bathroom

    What does 50W per hour mean?
  8. duke37

    Transformer identification

    Disconnect the rectifier and check the diodes. Connect a bulb across the blown fuze and see if it lights brightly without a load. I see it is a stereo amp so you can disconnect each amp and see if the connected one causes the fault
  9. duke37

    Transformer identification

    Disconnect the rectifier and check the four? diodes for shorts. Connect a mains light bulb to a blown fuze to limit the current. If the light is dim, the transformer is OK. Then work towards the output or start at the output by checking the output transistors.
  10. duke37

    Voltage Regulator Build

    Rectify the 60V AC to give 85V DC on a fat capacitor. Use a buck convertor to drop to 14V DC regulated. This will have high efficiency. You may be able to do without the capacitor if the convertor will not object.
  11. duke37

    Power resistor help

    Welcome to electronicspoint I think it is a 5W 0.18Ω 5% tolerance Probably used to measure current with low voltage drop.
  12. duke37

    Mosfet Buffer Amp Circuit Help

    Use a resistor.
  13. duke37

    Input lower than set output for LM2576

    I cannot answer your question. You can get an adjustable 2576 which will run off your 24V supply. It is better not to use components in a way which is not specified.
  14. duke37

    Soft touch power switch

    I bought a bare board component tester and made a plywood box for it. To turn it on, I push a small screwdriver through a hole.
  15. duke37

    Trumps solar wall, forget politics we should just build the thing

    The wall will be in the wrong place when the USA gives California and Texas back to Mexico.:D
  16. duke37

    Transistor-triggered photogate

    The tube will not flash with 200V across it no matter how it is connected. Put 200V across the tube and put a low volage pulse into a pulse transformer and this will output a high voltage pulse. If this is connected to an external electrode close to one main electrode, then a small amount of...
  17. duke37

    Input lower than set output for LM2576

    Most convertors are either boost or buck although you can get some which will do both. The LM2576-12 is a buck convertor for dropping the voltage. Feed the second convertor from the power supply and change the feedback resistor for the lower voltage when necessary. Is this right? Condition 1...
  18. duke37

    Charging from a 12v battery. Possible to increase current?

    The batteries will not be charged at 12V, it is not enough. Car batteries are charged up to 13.8 to 14.4V. Measure the voltage under load.
  19. duke37

    Charging from a 12v battery. Possible to increase current?

    If you have two 12V lead/acid batteries, they can be connected in parallel to increase the stored charge. A lead/acid battery should be able to supply what is needed to run through a USB cable. If it will not, then I suspect that the batteries are not being charged sufficiently and will suffer...
  20. duke37

    Bose AWRC1G wave radio

    A 75Ω connection describes the impedance of the cable which should be connected to an antenna of 75Ω. A dipole half a wavelength long will look like a 75Ω resistance at its resonant frequency. There will be no DC connection between the two sides. Some antennae have folded elements and will show...
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