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  1. duke37

    Aqualisa Lumi 10.5kw no power

    Are they resistors or inducors to reduce interference? The solder joints in P3 lokk very good but can touch and blow out the inductors. The joints should be sleeved, possibly with heat shrink sleeving. Someone may be able to translate 123K 12k mH?
  2. duke37

    Supercapacitor safety

    If there is inductance in the circuit, then high or very high voltages can be generated.
  3. duke37

    Delayed buzzer for Motorbike

    D2 and D3 are to protect the input from power supply spikes. R1 and C3 produces a reset on switch on so that the counter starts at the very beginning, a very good place to start.:) Snap!
  4. duke37

    Newbie question about transformer inputs

    The VA rating of the transformer is a bit irrelevant, this is an indication of the output which the transformer will give continuously. Here the transformer was shorted and the current was limited by the wire resistance as Minder said. It will be several times that on normal full load. The...
  5. duke37

    Newbie question about transformer inputs

    I would think that the 227V primary should be connected to the two phases of the supply. The shorting of the transformer will cause enormous currents to flow giving heat and the likelyhood of ruining the transformer. It would seem that the installation is faulty and dangerous. 1. Any live...
  6. duke37

    Solar lights to DC

    You should not use just a transformer, that will give you AC which is not be desired. You should use a power supply which gives DC regulated at the battery voltage., Make sure the polarity is correct.
  7. duke37

    Delayed buzzer for Motorbike

    If D1 was paralleled with another diode to get power from left and right blinker and C1 made much bigger, then a separate power supply may not be needed. Two blinker inputs through diodes and a 1k across D2 would give a good clock from either side. My book says that the input rise time should...
  8. duke37

    Ground loop filter

    I think I remember many years ago of seeing a circuit to transmit audio via a optoisolator. The idea was to use two identical isolators, one transmits across the gap and the other is used for feedback to adjust the drive so that the output matches the signal.
  9. duke37

    Delayed buzzer for Motorbike

    I do not have time to design your circuit in detail, perhaps you could do it yourself. You could use a schmitt trigger (4093 or 40106) to debounce the input and then feed the signal to a 4017 Johnson decade counter. A reset input would be necessary.
  10. duke37

    Building a custom frequency generator

    If you wish to consider free energy systems you really must study physics. Even if by some miracle you find energy, then you will have to deal with it by conventional means. A digital watch uses a low power oscillator and will run on a small battery for years. CMOS circuits use very little...
  11. duke37

    Transistors

    I do not think that you will see much difference between the two junctions. Leakage between collector and emitter should be low but may be significant with old germanium transistors. Most digital meters have a socket for testing transistors. If you find the base and test the gain, then with...
  12. duke37

    Purpose in syncronizing electronic signals

    Transmitters can be synchronised so that a beat signal is not generated in the area where both signals are received. Phase sensitive detectors can be used to increase sensitivity and reduce noise. A transmitter and detector can be synchronised from a satellite and radio signals of no more than a...
  13. duke37

    20 Watt LED Dimmer Circuit diagram

    Simple pulse width modulation will flash the leds on and off. If this is done fast enough, the human eye averages the light. What does your shark think? Will he have a migraine or a seizure?
  14. duke37

    AC Adapter model AA-091AD not working

    How then did you measure the output open circuit in #1? I would think that the PSU is nothing more than a transformer and if you have output, there should be a measurable resistance at the output with no input.
  15. duke37

    Xmas light string blinker for LEDs?

    The op shows " Although they are functional, the LED strings apparently don't draw enough current to trigger the flashing" I would just draw enough current to make them work. We have plenty of two way adaptors in the UK. I don't know what you have in Outer Mongolia.
  16. duke37

    Xmas light string blinker for LEDs?

    I don't know why I should be of able to help in this complex case. I would suggest that you use an adaptor, one input and two outputs and put a small bulb (globe) in the spare socket. You could make a circuit to do the job but it would need a fairly complex circuit and would need a box to house...
  17. duke37

    AC Adapter model AA-091AD not working

    The adaptor gives AC out. If you want DC then get another adaptor with sufficient current capacity to suit the load. It may need to have a stabilised output. Stuffing AC into a DC load may have caused damage, perhaps that is why the AC adaptor has an open circuit secondary. Another reason for...
  18. duke37

    Issue with supply not turning off sometimes

    I see that it is a switch mode power supply. These have a large input capacitor which take a massive current when first charging. Do the relay terminals weld together? TVs which I have seen using a SMPS often have a series 4Ω resistor to reduce the inrush (to 60A).. Also consider Bluejets racing...
  19. duke37

    Issue with supply not turning off sometimes

    I have had another look. It seems that the relay switches the AC mains supply to the PSU (which must have two wires). This presumably has a transformer in it which is inductive and will stop the current dropping rapidly. You could try a voltage suppressor across the power supply input. I do not...
  20. duke37

    Issue with supply not turning off sometimes

    It would help if you said which contacts are arcing. A flywheel diode can be connected across the relay coil to reduce arcing.
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