Search results

Search Forums New Posts
  1. KrisBlueNZ

    Can't find proper fuse!

    Digi-Key have a couple of 12.5A 20 mm ceramic fuses: http://www.digikey.com/product-detail/en/021612.5MXP/F4627-ND/1211169 http://www.digikey.com/product-detail/en/0001.1015/486-1786-ND/639739
  2. KrisBlueNZ

    Need a cross reference for MOSFETS

    Do you know how those two MOSFETs are used in the circuit? Do you know if they're opposite polarities? What package are they? Start by uploading photos of both sides of the board. Also post the power rating of the set. There's not likely to be anything special about those particular part...
  3. KrisBlueNZ

    Need a cross reference for MOSFETS

    O
  4. KrisBlueNZ

    CRT TV doesn't turn on

    Thin faint not-quite-horizontal lines at the top of the picture are called retrace lines. They indicate that the electron guns are being enabled before they have returned past the top of the screen ready for the start of a new field. It's normally caused by a problem in the frame output stage...
  5. KrisBlueNZ

    Need a cross reference for MOSFETS

    Have you done your due Google diligence? You're not the only one to ask, but I don't see any answers. Have you considered replacing the whole board?
  6. KrisBlueNZ

    RC circuit

    You're right Colin. When pin 3 goes low, the capacitor will discharge most of the way through the input protection diode on pin 5, and pretty quickly.
  7. KrisBlueNZ

    Transistors switch on output pin or input pin

    It's for temperature compensation. The VBEs of the two transistors are supposed to track each other fairly closely. The transistors may be strapped together. Edit: Yes it would be helpful to see the whole circuit and to know what it does. You (Davewalker5) have posted at least five snippets of...
  8. KrisBlueNZ

    Finally got me a 'scope - Have some questions

    Yep. It might be a good idea to find out. It's important for the safety of everyone in the house. Over here, they're usually just outside an outside wall, or possibly under the house somewhere near the switchboard, if you have a crawl space. Yes, that's safe, if you have a digital multimeter...
  9. KrisBlueNZ

    RC circuit

    It would help if you drew the NAND gates inside the 4093 packages. The circuit you have there is called a C-R "differentiator". At idle, pin 3 is low, and pin 5 is also low because the 47k resistor pulls it low. So the 15 nF capacitor is discharged, i.e. it has no voltage across it. The...
  10. KrisBlueNZ

    pulse generators

    That's an interesting claim, Colin. Here's the full "article" from Colin's PDF, available at http://www.talkingelectronics.com/projects/200TrCcts/101-200TransistorCircuits.pdf Simon, I'm interested to hear how you go with this design. Please keep us informed!
  11. KrisBlueNZ

    Help with switching

    I'm sorry, but automotive modifications is one of the subjects that is banned from discussion here on Electronics Point for reasons of legal liability and safety. I am closing this thread.
  12. KrisBlueNZ

    RC circuit

    Hi there and welcome to Electronic Point :-) A diagram would clarify what you're asking. If you have gate A output connected through a resistor to gate B input, and a capacitor from gate B input to 0V, this forms an R-C delay. When gate A output goes high, the capacitor will start to charge...
  13. KrisBlueNZ

    Designing a Time Delayed Relay

    Yes, of course. Post it here.
  14. KrisBlueNZ

    Designing a Time Delayed Relay

    Not really. I recommend doing the corners first, whether you use reel solder or solder paste.
  15. KrisBlueNZ

    pulse generators

    Hi Simon I don't think you will be able to do what you want to, given the size and weight limits and the amount of attenuation that would be caused by that much earth. I may be wrong. Do a Google search for similar products and you will see what the practical limitations are.
  16. KrisBlueNZ

    Designing a Time Delayed Relay

    Sorry, that's a mistake on my schematic. It's a multi-layer ceramic capacitor (MLCC) and they are non-polarised. With THT components, personally I just bend the leads slightly. With SMT you can use a dab of glue but I find it easier to tack one corner pin, adjust alignment if necessary, tack...
  17. KrisBlueNZ

    problem in 12v - 230v inverter

    It's still too small to see clearly. Try taking a close-up of the used part of the circuit board. Also while you're at it, join those heatsinks together with some nylon nuts and bolts. They're just an accident waiting to happen.
  18. KrisBlueNZ

    No Color. Black and White Picture

    I think you must have your details wrong.
  19. KrisBlueNZ

    A replacement for a photodiode

    Can you tell us more about what you want to do? "current source of 10~40 mA, 1~5 µs pulse" is not very specific. If you describe your whole project, we may be able to help.
  20. KrisBlueNZ

    Need help with repair

    Hi Trevor and welcome to Electronics Point :) We can probably help, but we definitely need more information on this board. Can you take some better photos. One from directly above and one from directly below, centred and with no rotation so we can line them up and trace out the circuit. See...
Top