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  1. KrisBlueNZ

    Boost Converter with mc34063

    No, sorry. Texas Instruments may provide a SPICE model but then you would have to buy SPICE.
  2. KrisBlueNZ

    12v LED Strobe Controller

    Yes.
  3. KrisBlueNZ

    transformers back to back - why won't work?

    Interesting explanation as usual Hop, although I didn't understand that much of it! Can you address directly the question of what limits the output power in this step-down/step-up application?
  4. KrisBlueNZ

    12v LED Strobe Controller

    Hi Peter :-) That circuit at top right is a two-stage protection circuit to protect the semiconductor circuitry from noise, spikes, and surges on the automotive supply, which is normally very electrically noisy. The varistor is there to protect against load dump, which will occur if the...
  5. KrisBlueNZ

    Help connecting Firecom UH-1 headset to Xbox 360

    OK. Take a methodical approach. Take a photo of each component inside the headset. This will be the earphone, the volume control, and the microphone, right? Edit the photos to add a number beside each terminal. Make a list of the wire colours at the plug end of the cable. Then take them one at...
  6. KrisBlueNZ

    Bush DAB Radio

    OK, that picture is pretty poor as well. But you can see the two thick tracks coming from each speaker connector towards the two 8-pin ICs on the left. Can you take a good clear picture of that area - those two ICs and all surrounding components - and post that? We should be able to tell you...
  7. KrisBlueNZ

    Translate stripboard layout to schematic diagram

    That hand-drawn schematic is a lot easier to read. There are still some errors though. Pin 4 of the 555 is not connected to pin 7. It's connected to the main positive rail via a link right next to the two 10 µF electrolytics. Pin 6 of the LM386 is not connected to the LED. It is actually the...
  8. KrisBlueNZ

    How does a DC air ionizer work?

    http://www.d-e-f-i-n-i-t-e-l-y.com/
  9. KrisBlueNZ

    How does a DC air ionizer work?

    So are you going to take Dave Jones's advice and "Don't turn it on... take it apart!" ?
  10. KrisBlueNZ

    How does a DC air ionizer work?

    Considering that the health benefits of ionised air are unproven (AFAIK), there might not be anything in it! But I'd be keen to see inside it. Teardown! Teardown! Teardown!
  11. KrisBlueNZ

    Designing a Time Delayed Relay

    That's good. I don't normally put a circuit description in my source code - just a summary of the signals on the device pins and for each possible state, what they mean (for inputs) and what effect they have (for outputs), but if you aren't going to document it somewhere else, I guess that's a...
  12. KrisBlueNZ

    Suggestions for building a PIC dev. board?

    Yes, exactly. All of that, and perhaps some flexibility for powering options - 5V and 3.3V regulators, and jumpers between them and VDD, and VDD brought out to the power connector too, so it can be powered directly from an external supply. I suggested some types of support circuitry in post...
  13. KrisBlueNZ

    Bush DAB Radio

    The first board is just the display/control board. The amplifier is probably somewhere on the second board. Can you post an in-focus picture of it? And can you tell us which wires go to the speaker.
  14. KrisBlueNZ

    Designing a Time Delayed Relay

    No worries! Your priorities are for you only to determine, and you can't do everything at once!
  15. KrisBlueNZ

    Help connecting Firecom UH-1 headset to Xbox 360

    Hi there and welcome to Electronics Point :-) I've been unable to find any technical documentation on the UH-1. It looks like it's obsolete now. There is documentation on other UH- series devices but it doesn't tell you which wire is which; it only covers the original plug: If you want to...
  16. KrisBlueNZ

    Designing a Time Delayed Relay

    I'll take your word on the LOTR reference... that fantasy stuff doesn't do it for me :-) Yes there's a fair bit of learning but you have such a great attitude I'm sure you're already taking it in your stride. And there are many people here who can help. Have you written up your initial comments...
  17. KrisBlueNZ

    Suggestions for building a PIC dev. board?

    Well, it depends what you want. You can have one board with all the peripherals on it, like the Gooligum board, and just use it for prototyping and do a completely new layout for each project, but if you only want one or two boards for a particular application, it's more economical to design a...
  18. KrisBlueNZ

    Suggestions for building a PIC dev. board?

    I agree with the female socket strips along both sides, but I'm not sure about using a 40-pin ZIF socket - you're not likely to be removing and refitting devices much (since you'll have an ICP connector on the board), and machine screw sockets like on the Gooligum board would be cheaper, and you...
  19. KrisBlueNZ

    Designing a Time Delayed Relay

    Wow! That's brilliant John! The soldering on U2 looks just perfect! Now you "just" need to write the software to control it!
  20. KrisBlueNZ

    Capacitors

    It looks like it's an electrolytic. You could be seeing its internal inductance. Can you draw a connection diagram of how you're testing it, and show the value of the current shunt resistor.
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