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  1. KrisBlueNZ

    Translate stripboard layout to schematic diagram

    OK, thanks for the link. There is a proper sized image. Do you have some schematic drawing software? Start by placing the ICs (555, LM386) then the smaller parts. Yes, I noticed that the instructables article has disappeared.
  2. KrisBlueNZ

    power supply faulty

    Hi Marius and welcome to Electronics Point :-) Are you sure they're 1600 µF? They would be pretty big! Can you show us a photo?
  3. KrisBlueNZ

    No vertical in crt tv(Need Help)

    Hi there and welcome to Electronics Point :-) I wouldn't take too much notice of the voltage you measure on pin 10 of the flyback transformer. This voltage is not a sinewave, so a standard multimeter (that doesn't have true RMS capability) will not measure it correctly. IC501, the STV9379, is...
  4. KrisBlueNZ

    MOSFET H-bridge, weird effect...

    Sure. You need to saturate the transistors otherwise they will dissipate a lot of power. But MOSFETs are the way to go. I wouldn't even be considering transistors. That's why I recommended that you avoid the L298 in another thread.
  5. KrisBlueNZ

    Help on 74LS165

    I don't know. I only know enough to warn you that if you run unbalanced logic signals and power and ground over distances, there will be... trouble. How about putting a small microcontroller on each module and using that to acquire the inputs and drive the LEDs? For communication you could use...
  6. KrisBlueNZ

    I would like to have an LED timer made

    Small battery, reasonable battery life, and LED display: pick two; you can't have all three. Are you sure you need an LED display? If not, opening and modifying a stopwatch would be a simple and cheap option.
  7. KrisBlueNZ

    Mono signal won't work with a stereo aux in - no sound at all ?

    Try a different cable between the mic preamp and the automotive audio system - either mono-to-mono or stereo-to-stereo. If that works, the automotive system that it doesn't work with has a mono input and the ring contact is grounded; that would short out the signal when you plug in a stereo plug...
  8. KrisBlueNZ

    Merry Christmas to all!

    Same to you, and to Ian and all of our moderators and members! I've had a good year here on Electronics Point and next year will be even better :-)
  9. KrisBlueNZ

    Microphone circuit assistance?

    Well, I just learned something interesting. On a standard TRS microphone input, the computer (or sound card) actually provides DC bias voltage for condenser microphones on the ring contact. (It takes the signal from the tip contact.)...
  10. KrisBlueNZ

    Translate stripboard layout to schematic diagram

    I've fixed the thread title. That's stripboard. This is tagboard: That image is pretty small. Is there a larger version? Perhaps you could post a link to the article on instructables.com?
  11. KrisBlueNZ

    Microphone circuit assistance?

    Check for continuity between the tip and the ring on the microphone plug. The microphone may be connected to both left (tip) and right (ring). As you say, the microphone is mono, and AFAIK the microphone inputs on computers are mono as well. Electret condenser mics need a power source.
  12. KrisBlueNZ

    Anyone able to help me out for my invention?

    No, zener diodes pass current in the reverse direction when operating in the zener region. They conduct in the forward direction just like a normal diode. So when the drain of Q1 goes more positive, due to the inductive kickback, the normal diode is forward-biased and the zener is...
  13. KrisBlueNZ

    Anyone able to help me out for my invention?

    You would need some way to discharge the capacitor quickly when the trigger is released. If the trigger is a SPDT type, that might be possible. Otherwise I don't think that's the right approach. Also, using a capacitor won't give cleanly defined ON and OFF transitions to the solenoid; I'm not...
  14. KrisBlueNZ

    Transistor base resistor calculation on 2N4401

    I think it's probably better to work it out based on the hFE of the transistor. Divide the collector current by the minimum specified hFE at that collector current, then multiply by a "fudge factor". That's the way I described it in one of those resources. A big power transistor may only have a...
  15. KrisBlueNZ

    analog clock on ntsc display

    Five years ago I was using the MSP430F1611 which has 10 kilobytes of RAM.
  16. KrisBlueNZ

    Kenwood KR-8050. A+B Speaker selection not working.

    So they are! Good catch.
  17. KrisBlueNZ

    simple tone generator

    OK. Ironically, that makes things more difficult! In that case, your simplest option would be an XR2206. They're no longer manufactured, but you can get them on eBay. You can also get kits based on them.
  18. KrisBlueNZ

    Saturation in transistors (BJTs) - why and how

    Right, that's the thrust of the resource - that you need "too much" base current. I mentioned forward-biasing of the base-collector junction as one way to define saturation, but no matter how you define it, there is no clear demarcation between "not quite saturated" and "saturated". Even if you...
  19. KrisBlueNZ

    Kenwood KR-8050. A+B Speaker selection not working.

    You can check for the correct continuity patterns in all positions of the switch. There's not enough information on the schematic for me to write up a checklist, but you may be able to figure out which pins are supposed to have continuity in each position by looking at the diagram of the switch...
  20. KrisBlueNZ

    2-10v or 4-20 dimming of 120v light bulb

    You know what happens when you ass-u-me :-)
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