Search results

Search Forums New Posts
  1. KrisBlueNZ

    Lights when audio is triggered

    Hi Paul and welcome to Electronics Point :-) Thanks for your thorough and detailed project description. It's amazing how few questions we get with proper explanations like that. I think you're onto something with your idea of splitting left and right channels and using one for user audio (I...
  2. KrisBlueNZ

    Designing a Time Delayed Relay

    You had a live (or potentially live) track on one side, crossing over a grounded (or nearly grounded) track on the other side, so you were using the board thickness as an isolation barrier. I don't know what the regulations say about it, but I've never seen that done, and I would never do it...
  3. KrisBlueNZ

    new here, H-bridge frustrations...

    Yes, it will work fine. The only problem is the voltage drop in the output transistors, as I pointed out. Measure the voltage across the load; it will be at least 1.2V less than the power supply voltage.
  4. KrisBlueNZ

    Designing a Time Delayed Relay

    Yes, the schematic in post #277 is good. I would avoid having the top side track from pin 2 of the mains input connector crossing the bottom side track from the positive output of the bridge rectifier to the smoothing caps. Actually I would move those tracks from the bridge to the caps further...
  5. KrisBlueNZ

    Designing a Time Delayed Relay

    Thanks for the info and advice Adam. Those connectors are the rising clamp type, so bare stranded wire is appropriate. I think the tinned copper wire is probably individually tinned strands. Is that right John? But I don't think you're considering that option now, right? That creepage and...
  6. KrisBlueNZ

    Bonjour tout le monde!

    No guys, I don't speak French at all. Google Translate did that for me. I should have said so. In fact I shouldn't have posted in French anyway. As you guys said, this is an English language forum.
  7. KrisBlueNZ

    My socratic homework

    Blimey! I wasn't expecting the Spanish Inquisition! But I have noticed in the past that your posts in the homework forum were quite direct and did not follow the stated guidelines. I guess if you're not giving the answer directly, a good alternative is to ask questions that are designed to...
  8. KrisBlueNZ

    LED TV - power circuit damaged after lightning strike

    What's the story with D612? If R610~613 were fried, D612 would have been damaged as well. Have you replaced it? Does it try to start up when you first apply power? If so, check the VCC circuit - D608, D618, D613. If D613 is short, it will prevent the converter from starting up properly. Also...
  9. KrisBlueNZ

    Bonjour tout le monde!

    Bonjour Charles. Se il vous plaît être conscient que le spam ne est pas toléré dans ces forums. Edit: No, I don't speak French. But Google Translate does.
  10. KrisBlueNZ

    new here, H-bridge frustrations...

    You don't understand voltage and current properly. When a circuit can't supply as much current as the load wants, the voltage drops. Voltage and current into a load are interrelated. Do some web research on the relationship between voltage, current and resistance in relation to drivers and...
  11. KrisBlueNZ

    Adjustable brightness torch??

    Schematic as promised The 555 oscillator is exactly as before, apart from the addition of a decoupling capacitor, CD1, which must be connected as directly as possible between pins 1 and 8 of the 555 to ensure reliable operation. The 555's output feeds U2, a Microchip MCP1407 low-side MOSFET...
  12. KrisBlueNZ

    My socratic homework

    Edit: this has been moved from a question in the homework help section. Kris's post seemed to be a good place to start this new thread, even if what he says at first seems a little odd as the opening post in the off-topic area. This is the homework forum Laplace. I was asking those questions...
  13. KrisBlueNZ

    What cable/wiring to use with electret condensor mic

    Sure, try it. Cheap cables can be microphonic (i.e. they pick up vibrations and convert them into signals), they can have high capacitance (which will show up as a lack of high-frequency response), and they can use very thin copper and therefore break easily, and the shielding is not likely to...
  14. KrisBlueNZ

    Adjustable brightness torch??

    Yes, a 12V, 100W halogen bulb will draw 8A, and that's at full operating temperature. It will draw more current at lower brightness because the filament resistance will be lower because it will be cooler. This could well cause problems. The important factors are: The MOSFET must be a type with...
  15. KrisBlueNZ

    LED TV - power circuit damaged after lightning strike

    Yes, possibly. I don't know if you'll be able to get it though. First, have you checked R610,1,2,3? If they're open, they'll stop the controller IC from generating any drive.
  16. KrisBlueNZ

    Designing a Time Delayed Relay

    The power and power switch connectors are still too small and the clearances around them are too tight. The electrolytics are OK there but the track from the negative terminal to the earth pin on the incoming power connector doesn't need to go there - I would run it north-east from the negative...
  17. KrisBlueNZ

    power supply Power good signal

    Agreed. But don't encourage him! LOL
  18. KrisBlueNZ

    power supply Power good signal

    Measure it with your eyes and your brain. The LED should not light up immediately when you switch the power supply ON. It should light up within one second, and should remain ON. That is the simplest way. The exact timing of the +POWERGOOD signal is not critical and a visual check is fine...
  19. KrisBlueNZ

    power supply Power good signal

    OK, if you had started this thread with that question, you would have saved ten posts and a lot of time. You can monitor the Power Good signal using an LED and series resistor like this: When you turn the power supply ON, the LED should remain unlit for about 0.1 seconds, while the power...
  20. KrisBlueNZ

    AC adapters

    Right, you can't. As duke37 says. In a standard mains-powered ("off-line") power supply, the incoming mains voltage is converted from AC to DC by a bridge rectifier and smoothing capacitor. This DC voltage then powers the next section of the power supply, which is a switching converter that...
Top