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  1. KrisBlueNZ

    Assistance with Transistor Theory

    OK. Thank you, and Ian, very much for trying to explain it. I don't understand the physics so I'll try not to make any more judgement calls on whether BJTs are current-controlled or voltage-controlled!
  2. KrisBlueNZ

    Sending Files Over the Internet

    I guess it's "No Sh*t, Sherlock"! This may not help, but I don't think I saw the option of an upload site mentioned. There's Google Drive and others, which sync automatically to computers, but you can also just upload and download files explicitly to various cloud storage sites and handle...
  3. KrisBlueNZ

    Triac question

    OK, here's the schematic: You haven't shown what you want to do with it, but when this circuit is powered off, the triacs will have no effect, and the bulbs can be powered through an independent path.
  4. KrisBlueNZ

    how a simple bit/data synchronization work?

    This seems like a pretty strange question. Decoding the data in an infra-red remote control datagram is normally done after the 37 kHz carrier has been removed. You can get receiver modules that produce a demodulated output signal ready for decoding by a microcontroller. The protocol is...
  5. KrisBlueNZ

    HICON crt tv no power

    Hi there and welcome to Electronics Point... Sorry for the slow reply! What's the model number of the TV? Have you looked for service information for it? Can you upload a photo of the power supply board or the power supply section of the main board?
  6. KrisBlueNZ

    Changing strobe pattern?

    Yes, that's the idea. It's a bit hard to follow with just pin numbers; better to mark the pin functions on the inside of the IC rectangle, and the numbers on the outside. You'll need to connect pin 13 of the second 4017 to 0V. You can't leave it floating just because you're not using it. Also...
  7. KrisBlueNZ

    Assistance with Transistor Theory

    I can see two reasons why it's helpful to describe it that way: (a) VBE causes IB and (b) IC is approximately proportional to IB and is not approximately proportional to VBE. I see your point that voltage is required in order for current to flow. I've said this many times during this thread...
  8. KrisBlueNZ

    Changing strobe pattern?

    The first one. As soon as the 4017 advances to count 2 and Q2 goes high, the 4017 resets and returns to count 0, so the time it actually spends at count 2 is almost zero (just long enough for the internal propagation delays inside the IC). So for all practical purposes, it alternates between...
  9. KrisBlueNZ

    Changing strobe pattern?

    Bob, you're getting a bit predictable with your "everything should be done with a microcontroller" mantra. I agree this project would be an ideal application for a microcontroller, but I certainly don't agree that almost every project (your words) should use one. I've explained to you before...
  10. KrisBlueNZ

    Trying Buck Converter on Pspice

    Ditto for my post #3 from the third paragraph onwards.
  11. KrisBlueNZ

    Pulse delay circuit

    Why don't you tell us about your whole project. WHY do you need to do this? Where is the input pulse coming from? What is the output pulse used for? Why do you need to vary the delay? What is the delay control signal coming from? There are lots of ways to do what you describe, but some will be...
  12. KrisBlueNZ

    Homemade Ecaller Advice

    Yeah. I guess all we can do is present some suggestions and let him have a think about it.
  13. KrisBlueNZ

    Homemade Ecaller Advice

    The reason I suggested sending the audio remotely is that I assumed the OP would prefer to be able to choose the audio depending on the behaviour of the animal(s) he is trying to attract. If he simply wants to play a predetermined sequence of sounds, then an on/off control would be fine. Edit...
  14. KrisBlueNZ

    Changing strobe pattern?

    You can't easily do that. The 4017 can be configured to divide by any number from 2 to 10 inclusive, but not more. For what you want, you need a new gap between Q4 and Q5, and another new gap between Q9 and Q0. That means you need to divide by 12. There are ways to hack delays into the clock...
  15. KrisBlueNZ

    Homemade Ecaller Advice

    Hi there and welcome to Electronics Point :-) Thanks for giving us the background to your project. This makes it a lot easier to give you useful answers right from the start. Starting from the basics... As Gryd3 says, that amplifier is totally unsuitable. Its output power will be around 1~2...
  16. KrisBlueNZ

    Triac question

    Hi there and welcome to Electronics Point :-) You haven't given us enough information to give you a clear answer. Can you tell us the part number of the kit and/or post a link to the page? Can you find a picture or diagram of the kit and edit it to show how you want to connect it, and upload...
  17. KrisBlueNZ

    Some questions for my Container Overheat Indicator

    You posted the same question to two different threads; one in General Electronics Chat and one in Electronic Projects. Predictably, this has caused confusion and duplication of effort. DO NOT do it! I have merged the other thread into this one. This is not an ideal solution because posts from...
  18. KrisBlueNZ

    Some questions for my Container Overheat Indicator

    Yes, you should have a diode connected across the coil of your 3PDT relay to protect the relay driving output of the temperature controller from inductive kickback from the coil of the 3PDT relay when the temperature controller turns its output OFF. This inductive kickback can easily damage a...
  19. KrisBlueNZ

    Designing a Time Delayed Relay

    Use the and tags around it. Unfortunately the XenForo text editor won't let you paste more than two spaces in a row, even into a CODE block; it reduces them to two. Very irritating. So you have to go through and tidy up the lines to make the columns line up.
  20. KrisBlueNZ

    Designing a Time Delayed Relay

    The on-board oscillator is just an oscillator that's designed to be fairly accurate and stable. I don't know how it's implemented. It's fully internal to the PIC. I thought it would be a good idea to have an accurate time source. Somehow I thought that your turn-off delay was going to be 1~2...
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