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  1. KrisBlueNZ

    Paint Sprayer Controller

    Sorry Rod! Yes, I'll move the thread to the Electronics Repair forum. I don't think it will attract much more interest though.
  2. KrisBlueNZ

    Circuit Board Design - DIP Switches? Jumpers?

    No, it's very old CAD software! Also, you could put a small gap e.g. 25 or 50 thou between the first three columns and the second three columns to make it impossible to put jumpers between columns 2 and 3.
  3. KrisBlueNZ

    Will a 12.5V DC power supply damage a 12V device ? See details inside..

    Hi and welcome to Electronics Point :-) I would be more concerned about the horrible electrical noise on the automotive 12V supply - unless the motor isn't running while you're using the microphone. This noise tends to get everywhere and is hard to eliminate. Let us know how it goes!
  4. KrisBlueNZ

    Stage Line 500W amp repair project

    I haven't forgotten you! I'll get back to you within 12 hours.
  5. KrisBlueNZ

    Aquarium canister water sensor fault

    I don't know. But if you bypass it, the pump will try to run even when there isn't any water in the canister, right? And that's why the sensor is there, right? The proper attitude to safety isn't to say "OK, you show me how a problem could occur"; it's "I will show you how no problem can...
  6. KrisBlueNZ

    Hello All!

    Cool! Like the sign on the toilet door says, "We aim to please. You aim too, please!"
  7. KrisBlueNZ

    555 monostable help

    You need to be clear. So you want a circuit that, when it receives power, waits five seconds then activates a relay for 0.5 seconds. Is that right? If so, it can be done with no 555s at all. Can you confirm that that's what you want? And what's your power supply voltage?
  8. KrisBlueNZ

    Circuit Board Design - DIP Switches? Jumpers?

    A 4x2 header won't work with simple jumper shunts. Here's maybe the simplest option if you want to use jumper shunts. As before, the blue tracks (underside) are the incoming signals, and the red track at the top are the outgoing signals. Every circle is a pin, and they're spaced at 0.1" pitch...
  9. KrisBlueNZ

    Hello All!

    Hi Ray and welcome to Electronics Point :-) I hope you enjoy your time here!
  10. KrisBlueNZ

    Circuit Board Design - DIP Switches? Jumpers?

    What comes to mind is a grid formed by four tracks on one side of the board, and another four track at a 90° angle on the other side, with some way to interconnect them. Here's my first thought; you can probably improve on it. The blue tracks (underside) are A~D from the driving device(s)...
  11. KrisBlueNZ

    LM386 Amplifier Module help

    As Dave says, use a multimeter set to the DC volts range (20V DC if it's not an auto-ranging meter) to determine which wire from the wall wart is positive and which is negative. Try them either way round until the reading is positive (no "-" sign on the display). The wire that's connected to the...
  12. KrisBlueNZ

    Dumb question re. simple inverter

    You could use two monostables (aka one-shots). It depends what you want to set, and what will be changing. Inserting a fixed-duration monostable between each output and each MOSFET gate will give you a fixed ON-time. If the 4047's frequency is fixed, this corresponds to a fixed duty cycle. If...
  13. KrisBlueNZ

    Dumb question re. simple inverter

    You need to be a lot clearer with your question. You want to reduce the duty cycle of what? How do you want to control the duty cycle? For what reason? What's the background to the project?
  14. KrisBlueNZ

    Need Help with auto switching Reverse Polarity Circuit

    See also the Wikipedia article at https://en.wikipedia.org/wiki/Medical_uses_of_silver which includes the following: Although that article is probably written by shills for the pharmaceutical industry who want to prevent honest alternative medicine practitioners from making a fair living...
  15. KrisBlueNZ

    Pioneer SX-1000TW main speaker output problem

    Hi there and welcome to Electronics Point :-) I've moved your question to a new thread. The circuitry between the amplifier output and the speaker connectors just consists of the rotary switch. So if one set of speaker connectors is good but the other isn't, the problem must be within the...
  16. KrisBlueNZ

    Paint Sprayer Controller

    Hi Rob. I'm not the best person here to be advising you. I haven't worked on high-power stuff like that. I hope someone else will come along and give some definite guidance. I agree that you should be worried about why the original triac failed, and I agree that just replacing it may just...
  17. KrisBlueNZ

    DS1307 can not read and write time in arduino.

    That's the URL of the discussion thread. Can you post the URL of the data sheet please.
  18. KrisBlueNZ

    LM386 Amplifier Module help

    Yeah, "plugpack" is just another name. Often they are called "wall warts" because they sit against your wall and look like a big black wart. Whatever you call it, they take power from the AC line (which some of us call "mains"), either 115V AC or 230V AC, and they convert it to a lower voltage...
  19. KrisBlueNZ

    Paint Sprayer Controller

    Well, I guess you could just try a triac with ratings that are sure to be higher than what's needed - for example the STMicroelectronics BTB26-600BRG (600V, 25A): http://www.digikey.com/product-detail/en/BTB26-600BRG/497-3398-5-ND/669155
  20. KrisBlueNZ

    LM386 Amplifier Module help

    Hi Tom and welcome to Electronics Point :) The LM386 is a very old design and there are much better options available. More modern devices can deliver much more power for a given supply voltage because they have a wider output voltage swing and use a trick called BTL (bridge-tied load), and...
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