Search results

Search Forums New Posts
  1. KrisBlueNZ

    12V - 350V 200mA converter for motorcycle CDI

    I would stop the Royer oscillator by adding two NPNs (e.g. BC547, 2N3904) on the TIP41 transistors. Each new transistor has its collector connected to the base of one TIP41 transistor, and its emitter connected to 0V. The bases of these new transistors are each connected through a 3k3 current...
  2. KrisBlueNZ

    12V - 350V 200mA converter for motorcycle CDI

    That's exactly right.
  3. KrisBlueNZ

    Transistor Saturation

    The diagrams you posted in post #5, and the formula you posted in post #6, all relate to FETs, not BJTs!
  4. KrisBlueNZ

    Faulty power connectors

    Oh. I didn't try measuring the connectors on mine. I just cut them up and threw them away. But it doesn't surprise me. There is no corner that certain companies won't try to cut. I'm actually surprised that there hasn't been more attention to this issue from interested groups like insurance...
  5. KrisBlueNZ

    Voltage Mofset Capacitor

    OK, that's fine. Do what I said in the first two paragraphs of post #3.
  6. KrisBlueNZ

    Operational Amplifiers

    The schematic in post #7 is different from the one at the start of this thread. If you exchange all of the inputs on your schematic in post #7 (you have them reversed), then it's probably easy enough to solve it. (I haven't tried.) But the schematic in post #1 is different. It has a voltage...
  7. KrisBlueNZ

    Voltage Mofset Capacitor

    OK, the best place to start is to take all the voltages, currents, and component values given in the question, and mark them in on the schematic diagram. Then you will be able to see what information is missing, and how you may be able to calculate it. So take a good, in-focus scan of that...
  8. KrisBlueNZ

    12V - 350V 200mA converter for motorcycle CDI

    OK, fine. Then do what I suggested in the bottom part of post #12. As I said in that post, I don't recommend it. Or use debe's circuit. It's called a Royer oscillator - see https://en.wikipedia.org/wiki/Royer_oscillator for details of the specific core characteristics needed.
  9. KrisBlueNZ

    what is this Circuit ?

    Yeah Dave, I was thinking maybe he would realise that his "answer" wasn't helpful and that he won't get any useful responses until he explains the context. That circuit, as drawn, has an input, but no output! It will do something, and it might even be useful. But without context, describing...
  10. KrisBlueNZ

    Operational Amplifiers

    There's a problem with that question. Look at V3. It's connected to the summing node at the inverting input of the first op-amp. The non-inverting input is connected to 0V. If that op-amp was operating (pun intended) normally, the inverting input would also be at 0V. But the question specifies...
  11. KrisBlueNZ

    Transistor Saturation

    What is the definition of saturation (for a BJT), according to your course material?
  12. KrisBlueNZ

    12V - 350V 200mA converter for motorcycle CDI

    No, that's not the kind of conditioning circuitry you need. You can't connect a simple inductive pickup directly to that point in the circuit. Post a link to the pickup you plan to use. The conditioning circuitry needs to make a clear decision on the correct time to fire the SCR, and it needs...
  13. KrisBlueNZ

    New to the forum!

    Hi there and welcome to Electronics Point :-)
  14. KrisBlueNZ

    12V - 350V 200mA converter for motorcycle CDI

    If you have a look at the UC384x data sheet you will see that it can be disabled either by grounding pin 1 or by forcing a voltage onto pin 3. In schematic #3 it is done using pin 3; in your circuit it is done using pin 1. It's actually most reliable to use pin 3. You have shown the pickup coil...
  15. KrisBlueNZ

    Will This Charging Circuit Work Well.?

    Well, at least they're consistent - they have a poor description to go with the poor design. OK. You want to charge them in series, right? I doubt it. The cells have a capacity of 550 mAh, so even if the solar cell is in direct, bright sunlight, and even if its specifications are not...
  16. KrisBlueNZ

    PLL (CD4046) FOR 50Hz

    1. You still haven't answered my question in post #2. 2. You don't need a bandpass filter to detect zero crossings. 3. You don't need a PLL to detect zero crossings. 4. If you want to communicate clearly with other people and not p*ss them off, you should not capitalise every 'd' you type. 5. If...
  17. KrisBlueNZ

    PLL (CD4046) FOR 50Hz

    In post #2 I asked you a question and told you that you haven't given enough information. You have asked three more questions. Start by answering my question and giving more information. What is the purpose of the circuit? How are you using it?
  18. KrisBlueNZ

    12V - 350V 200mA converter for motorcycle CDI

    Yes, the main switching transistor could be a Darlington. Lift the base and measure the base-emitter voltage to find out. I think that configuration is a blocking oscillator - see https://en.wikipedia.org/wiki/Blocking_oscillator but there may be some clever interaction going on between the...
  19. KrisBlueNZ

    Harman/Kardon HK6500. Loudness not working when button is pressed

    OK, if you need help, start a new thread for it.
  20. KrisBlueNZ

    what is this Circuit ?

    Where did you get that circuit from?
Top