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  1. duke37

    TURNS PER VOLT of a transformer winding

    Why not? I gave you a source of data which I have found useful. Doing a lot more research means that I will not be able to repair my mahogony box today.
  2. duke37

    TURNS PER VOLT of a transformer winding

    A excellent source of information on transformer design and manufacture is ludens.cl/electron/trafos.html I suggest you look at this. He gives a table of wire diameters, I believe that the current density can be 3A/mm^2. Chose a core of a size to give the VA you want. Work out the turns to get...
  3. duke37

    7404 Hex inverter stuck on 2.5v

    Is it a 7404 or a 7414 as in your diagram?
  4. duke37

    volume to liter conversion

    Some searching shows that there are 61 cubic inches in a litre.
  5. duke37

    RL low pass filter, Voltage across inductor at 100hz

    The output voltage will not be 1V since there is a 100Ω resistor to reduce it. LT spice uses peak voltage not RMS so watch this. 58mV across the inductor seems strange. What is the frequency to get this? Please show us a plot of the frequency response. It would help if you checked your spelling...
  6. duke37

    volume to liter conversion

    What is the 61 for? I have never met it. The cone with the top cut off could be called a tuncated cone. Use the S.I. system and there will be no conversions to be done as Dave says.
  7. duke37

    Considering a design change

    I have just tried to post a comment and the program would not accept it. Please let me know if you do not get this:).
  8. duke37

    Oscillator or Not?

    I think you are all too hard on shoebox. If the effect is large, it will be seen. If it is not seen, then the optimum conditions may not be met. It is known that light affects plants and, now that LEDs are available, the effect of wavelength is being investigated. Tomato plants are now grown...
  9. duke37

    choosing a resistor value

    You can get drinking bowls for pigs, they turn on the water as they need it. Can you train your dog to be as intelligent as a pig?
  10. duke37

    Changing LED colour in old hifi equipment

    A minor point, you used 8.2V in the earlier posts. In fact, the transistor drops about 0.2V when turned hard on so you have 7.8V to play with.
  11. duke37

    choosing a resistor value

    What about an ultrasonic distance module? What about a capacitive probe? What about a platinum electrode?:)
  12. duke37

    Explanation of different current/voltage types: RMS, Peak, Mean, DC, AC

    I looked up Wikipedia and they specify DC as one polarity and AC as repeatedly varying polarity. I am used to circuits where the DC varies and can be considered a mixture of AC and DC. Pehaps I shouldn't have tried to make a concise definition. Colin seems to think I do not know what I am...
  13. duke37

    Explanation of different current/voltage types: RMS, Peak, Mean, DC, AC

    DC Direct current, also used for voltage. This is where the voltage and current are constant and of only one polarity. The simplest to deal with. AC Alternating voltage/current. This may apply to sine wave or any other wave shape where the current changes sine. RMS Root Mean Square. This applies...
  14. duke37

    Convert +12V DC to -30V DC

    To Colin What mistake? Electrroda said that he can't supply with +/- 30V and I agreed with him. Of course he could supply with +/-30V but the result would not be happy. 40 years is a bit of an underestimate but I only do it as a hobby.
  15. duke37

    Low tension ignition inductor

    Hop The calculations could be wrong. The inductance equation uses inches and I converted to mm. Perhaps I got a 25.4 in a twist or perhaps I multiplied by N rather than N^2, will have to check. The engine is out of a car. I have not seen the engine or the car. I would doubt that the inductance...
  16. duke37

    Low tension ignition inductor

    I have been asked to wind a coil since I have most of an AVO coil winder. The chappy with the engine has made some parts for it so I am winning at the moment. Some calcs I have made Length 67mm OD 33mm ID 15mm Wire 0.686mm No layers 13 Turns/layer 98 Turns 1274 L (no core) 3.04mH R 3.9Ω V 12V...
  17. duke37

    Tv on a boat.

    If you start an engine with an electric starter, then high voltage pulses can be generated. A zener voltage limiter would be good.
  18. duke37

    Low tension ignition inductor

    I am looking for details of the inductor used in the low tension ignition of cars made about 1900. This is used to create a drawn out spark when the contact is opened. I would like size, number of turns, resistance,inductance, energy storage and core type if any. There seems to be no hard data...
  19. duke37

    Tv on a boat.

    These convertors use an inductor to pass the energy to the output and are quite capable of producing a very high voltage if not smoothed properly or not loaded. You could use it to float charge a battery - set it to 13.8V - and use the battery to drive to TV. Any spikes would be greatly...
  20. duke37

    convert 110v dc to 24v dc

    I said they were listed as AC and said in #10 why they should work on DC. In no circumstances get a transformer supply, this will go pop on DC. The cost is not too great to try and would be more reliable than a home built device.
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