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  1. KrisBlueNZ

    Recommend a Reliable Online Parts Store?

    Hi John and welcome to the Electronics Point forums :-) AFAIK Digikey and Mouser have the widest selection of components. After that, Element 14 / Newark / Farnell, and RS Components. None of them have free shipping. For motors, try robotics sites, although component suppliers (including...
  2. KrisBlueNZ

    Circuit Diagram for Tannoy i30 iPod Dock

    I'm not sure what you mean by "guest searching is not allowed". I'm a guest and I searched for Tannoy. But there were only four results, and none of them mentioned i30. If you've tried Googling Tannoy i30 dock schematic, or Tannoy i30 dock service manual, then you've done everything I can suggest.
  3. KrisBlueNZ

    Voyager Space Probe distance counter

    Re the family heirloom idea... it's a lovely thought but not practical. Nowadays, when electronic products are often obsoleted within five years, time scales over 20 years are seldom considered. Program retention in PICs is unspecified for cheap variants, 40 years for mid-range variants, and 100...
  4. KrisBlueNZ

    Dark activated light

    Well, you're doing OK for a 13-year-old! If you put your date of birth in your profile, we will see your age, and will be able to respond accordingly. It can also help if we know your location, so we know what component suppliers to recommend. OK, that circuit has a number of problems and can...
  5. KrisBlueNZ

    Circuit Diagram for Tannoy i30 iPod Dock

    You could try http://elektrotanya.com
  6. KrisBlueNZ

    Voyager Space Probe distance counter

    Hello Señor and welcome to Electronics Point :) Your project is fairly straightforward. It's actually just a kind of digital clock, but with a much wider display and some extra calculations. You will need: A microcontroller of some kind. Nothing powerful or fancy. This will contain the program...
  7. KrisBlueNZ

    Keep Blowing lm13700's

    You can use the log voltage-to-current converter stage from the diagram you posted in https://www.electronicspoint.com/threads/which-capacitor-is-best.269126/#post-1612612 in a separate thread. In fact you can use the whole VCO from that circuit. Have you given up on that design? If so, why?
  8. KrisBlueNZ

    Keep Blowing lm13700's

    It won't work because the LM13700 requires a current source (that sources current into pin 1) and that circuit is a current sink (sinks current to 0V). The LM13700's control input on pin 1 goes straight to the base of a transistor (IIRC) whose emitter is connected to the negative supply rail...
  9. KrisBlueNZ

    Bench Power Supply

    I think he's expecting 1.5A on each output.
  10. KrisBlueNZ

    Bench Power Supply

    Yes, as Olivier says, you can probably get away with two single-turn pots with resistances in a ratio around 30:1. The higher resistance one is the coarse adjustment. If you decide to go with that idea, I'll draw up a circuit. It's pretty simple. Also let me know if you want the tracking...
  11. KrisBlueNZ

    Omega special character

    I wish it worked for me! Û Û dammit! Û Û
  12. KrisBlueNZ

    555 voltage controlled oscillator question

    The amplitude of the triangle-ish wave will vary depending on frequency. So you would have to either vary the resistor in the integrator, or vary the comparator threshold, to compensate. If you need variable duty cycle independent of frequency, a good option would be the two-op-amp "integrator...
  13. KrisBlueNZ

    Omega special character

    What OS and web browser are you running, Harald?
  14. KrisBlueNZ

    Bench Power Supply

    That looks reasonable. I like the idea of using trimpots to set the output voltages. BTW I fixed your link so it points to the article. Previously it didn't work at all - the forum software included the trailing >> in the URL! You need to put the URL by itself. The diodes in the bridge...
  15. KrisBlueNZ

    555 voltage controlled oscillator question

    You can't vary the duty cycle by feeding the output through a comparator - the output is a square wave with a duty cycle of 49~51%. You would have a similar problem with the 555 circuit - the main output is a square wave, and the waveform at pins 2 and 6 would vary in amplitude and average...
  16. KrisBlueNZ

    555 voltage controlled oscillator question

    Haha! Yep. You could fix this, but since the control voltage works backwards (lower voltage = higher frequency), there's not much point. The usefulness of pin 5 on a 555 is limited to making siren circuits. You'll like the 4046. Just be careful not to damage it - keep the inputs within the...
  17. KrisBlueNZ

    led cube

    Hi and welcome to Electronics Point :) It's pretty inexpensive. I think it depends what you want to achieve. If you want to learn about electronics and microcontrollers, and if you want something you can hack and improve on as you learn more, you're probably barking up the wrong tree with this...
  18. KrisBlueNZ

    Op-amp, changing LED colour!

    Hmm. So it does. If you're talking about Q3034. The rail it connects to is marked 13.3V but if you follow it leftwards, it comes from the output of Q3025 where it is marked 3.0V. So that 13.3V marking is wrong. I've had a closer look at the diagrams. The voltage at the collector of Q3002...
  19. KrisBlueNZ

    Omega special character

    Obviously the best answer is for XenForo to provide a drop-down menu of Greek characters and other useful non-ASCII characters. In case it's useful, here's a list of non-ASCII characters that I use (or have used): Various Greek characters, including mu (230); plus-minus (241); multiplication...
  20. KrisBlueNZ

    Dark activated light

    Well, I Googled how to draw clean electronic schematic diagrams, and the first hit was this: http://electronics.stackexchange.com/questions/28251/rules-and-guidelines-for-drawing-good-schematics I take issue with a couple of the points but in general it's full of good advice and well-explained.
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