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  1. KrisBlueNZ

    power supply

    He may have misinterpreted your question as being "I have a technical question that you don't understand and can't answer truthfully, but if you answer yes, you will make a sale".
  2. KrisBlueNZ

    power supply

    You'd better make sure they're designed to be paralled. Standard power supplies aren't. That's why I suggested connecting some lower-voltage ones in series.
  3. KrisBlueNZ

    Testing a electrolytic Cap

    Don't ever buy critical components on eBay - it's a counterfeiter's paradise. And for electrolytics, stick with reputable brands. The Japanese ones are best: Nichicon, Panasonic, Rubycon, United Chemi-Con (UCC). Other reputable brands (someone correct me if I'm wrong) are EPCOS, Vishay BC...
  4. KrisBlueNZ

    The need for resistance

    Hi Dustin and welcome to Electronics Point :) Continuing from what Steve wrote... As Steve said, resistance, as a phenomenon, is not necessarily useful. When we specifically want resistance in a circuit, we use a resistor. The behaviour of a resistor is defined by Ohm's Law, which says: I =...
  5. KrisBlueNZ

    LTSpice switch

    It sounds like this is all homework stuff and should stay in the homework section... right?
  6. KrisBlueNZ

    Stage Line 500W amp repair project

    Just as a precaution. Both of those resistors have been pretty hot, so obviously, they've been stressed. Those caps are in series with those resistors. I couldn't say that they have failed and caused the resistors to be stressed, or that they have been unduly stressed. In any case, if they have...
  7. KrisBlueNZ

    Stage Line 500W amp repair project

    Good idea. You might also want to replace C11 and C21 with this type: http://www.maplin.co.uk/p/01uf-275v-x2-rfi-metallised-polypropylene-capacitor-n69cn
  8. KrisBlueNZ

    DVM meters with Square waveform mode

    Why don't you try it? Try it both ways - put the signal from the meter into the primary of the transformer and measure the secondary, then try it the other way round, so the transformer is being used as a step-up transformer. Be careful with the connections because there could be some...
  9. KrisBlueNZ

    Stage Line 500W amp repair project

    OK, good! That's right, R37 and R35 in the left channel, and R63 and R72 in the right channel, are not supposed to be fitted. If R70 measures 71.9Ω you should replace it with a resistor of similar size to R40.
  10. KrisBlueNZ

    DVM meters with Square waveform mode

    Mains / line frequency is 50 Hz in many places outside the U.S. including the UK, Europe and Oceania. In any case 50 Hz is not too far from 60 Hz. So that might be the right answer - that the meter might be slightly useful for testing mains (line) transformers. Good answer! Different voltage...
  11. KrisBlueNZ

    Stage Line 500W amp repair project

    Oh! I didn't mean you to take each one out and measure it! With all the semiconductors removed, most of them should measure OK in circuit. What values did you measure for R37 and R35? R70 and R40 should both be standard 4.7Ω resistors. Can you upload photos both of them so I know what you mean?
  12. KrisBlueNZ

    How would one make a power supply for a 30,000w xenon lamp

    Nothing good or useful will come of this thread. It's time to close it.
  13. KrisBlueNZ

    How can I build a simple sound system for my laptop?

    That looks OK. It's 18W/channel into 4Ω. Power into 6Ω will be somewhat less. But that's probably a reasonable match.
  14. KrisBlueNZ

    I need something that is LOUD ,but is still small ,and lightweight. HELP!

    In post #3 I suggested a BTL audio amplifier module capable of at least 10W. These are also available pretty cheaply on eBay.
  15. KrisBlueNZ

    find faulty capacitor in circuit if there are many

    That won't work - they're all in parallel! They will all measure short. There are ways to do this by passing a current into the short and tracing the voltage drop across the copper traces or the current flow in them, but you need a current tracer or a sensitive voltmeter, and you need to trace...
  16. KrisBlueNZ

    Beginner question regarding battery charge and circuits

    Hi Ben and welcome to Electronics Point :-) Right. The battery produces a voltage ("potential difference") between its terminals, and if an external circuit is connected to both terminals, current will flow from the positive battery terminal, through the circuit, and back to the battery...
  17. KrisBlueNZ

    I need something that is LOUD ,but is still small ,and lightweight. HELP!

    Yes, she will need an amplifier of some kind, which will need batteries.
  18. KrisBlueNZ

    DVM meters with Square waveform mode

    This thread is now open.
  19. KrisBlueNZ

    Logic set up times and hold times

    In order to moderate user "willwatts" we are allowing him one open thread at a time. He has asked me to reopen his "DVM with square wave mode" thread at https://www.electronicspoint.com/threads/dvm-meters-with-square-waveform-mode.271344/ at the expense of this one. This one is now closed.
  20. KrisBlueNZ

    NTSC camera to RCA

    Hi and welcome to Electronics Point :-) It's hard to say - we don't know what type of camera you have. Can you post a brand and model number? NTSC is a video standard for "composite video" that includes luminance (brightness) and chrominance (colour) on a single signal. In consumer equipment...
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