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  1. duke37

    Digital Tire Inflator unusable because of a spring/switch issue

    I do not think that the switches have any current trip, they are too small. The C and 11 and 14 look to be moulded in and may be the record of the moulding machine used. The metal mounting bracket will not be connected to anything. Such switches were used in old radios and could be obtainable...
  2. duke37

    Digital Tire Inflator unusable because of a spring/switch issue

    The switches look the same to me, The bottom tags are connected together so to interchange the switches it it only necessary to swap over the top black and red wires. It looks as if these are soldered.
  3. duke37

    How to Find Efficiency of Induction Motor

    I do not know what you mean by 3 phase power output. Efficiency is output/input. The output power is measured by the torque and speed as you have done. You just need to divide the two numbers and if you desire, multiply by 100 to get %.
  4. duke37

    Killing SSR (relays) - Need to understand

    Measure the voltage ACROSS the SSR when it is driving the load. You could get more margin with a 100A SSR.
  5. duke37

    flyback driver circuit

    Show us a circuit. If looks as if the BU508 (npn) is upside down but then it shouldn't work at all.
  6. duke37

    Harvesting parts from a car

    What you need is an old car to store them in.:)
  7. duke37

    Killing SSR (relays) - Need to understand

    Insufficient drive to the relay resulting in excessive dissipation?
  8. duke37

    Detecting A Knock Pattern

    There are morse code receiving programs. I wrote one many years ago for an Acorn Atom. The more I sent, the more the program seemed to understand me.:)
  9. duke37

    Dell adapter down!

    3.15A fuze?
  10. duke37

    Type of wires

    In #19 I suggested that you look up 'coaxial cable' on Wikipedia. This you did not do, it gives a lot of information on cable impedence.
  11. duke37

    dimmers?

    The effect of saturation will depend on the core. An E/I core will likey cope better than a torroid where the core is more tightly controlled. The higher primary current will give more heating and the transformer may well cater for this. A close rated fuze will help. I do not think that this is...
  12. duke37

    dimmers?

    A transformer run on AC sine wave has the magnetic flux varying from one direction to the other. The average flux is zero. The triac will be turned on by a diac and if this is perfectly symmetrical, the positive and negative parts of the waveform will be identical and the average flux will be...
  13. duke37

    J Type Thermocouple Signal Conditioning

    Perfection can not be obtained. My experience with thermocouples is that they are nearly linear. If you are using a computer then non linear correction could be invoked. The diode voltage drop will change by 2mV/degC - silicon or germanium. Why are you stuffing 5V across the thermocouple?
  14. duke37

    dimmers?

    A triac passes current in both directions on an AC suppy if everything is optimum. If the system is not quite symmetrical, then current can be passed in one direction more than the other. This can cause the transformer core to saturate and current will not be limited by the transformer...
  15. duke37

    Type of wires

    As I suggested, look up 'coaxial cable' on Wikipedia, it will dobtless tell you about cable impedance. It has nothing to do with distance. Why should we try to help you if you will not help yourself?
  16. duke37

    Finding the smallest possible actuator, or a new solution. Help massively needed!

    Have you looked at a dot matrix printer mechanism?
  17. duke37

    relocating a hot IC

    If you extend the connections to an op-amp, the system might go into oscillation due to added inductance and capacitince.
  18. duke37

    Type of wires

    Look up 'coaxial cable' on Wikipedia, it gives a lot of information there and details of the various types of coax. By circular cross wires, do you mean braiding?
  19. duke37

    uC controlled DC-to-AC inverter

    If you drive the transformer at too low a frequency, then the core will saturate and the input current will rise as voltage rises but the output will not rise in sympathy. You may be able to get away with a 240V 60Hz transformer operating at 90V and 20Hz but it will be close. If you have a...
  20. duke37

    LC filter Circuit HELP!!

    I know nothing about transfer functions but if you have C1 and L, then you can work out the parallel impedance of these two at 2kHz (it will be inductive). To make the circuit accept 2kHz, then C2 needs to have the same impedance but of opposite sign.
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