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  1. WHONOES

    Few questions about usage of TI BQ2054

    Schottky diodes have a lower forward voltage drop than conventional silicon diodes. The small amount of reverse leakage current they exhibit is neither here nor there. All diodes will exhibit a small amount of reverse leakage current, you can't get away from it.
  2. WHONOES

    Computer speakers power issue

    I'd go for Harald's suggestion.
  3. WHONOES

    Stage Line 500W amp repair project

    It's probably a bit late now but, it might be of some use to check the power supplies with the amplifier fuses out to see if they are OK. Is one of the amplfier's functioning correctly? If so some useful measurements may be made. Have now had a quick squint at the schematics and it looks a bit...
  4. WHONOES

    Few questions about usage of TI BQ2054

    The first Schottky diode is what is called an "idiot diode". It's there to stop all the circuitry downstream of being blown to bits if connect the power supply back to front. If you do so the diode simply becomes reverse biased. The second one performs a similar function for when the battery is...
  5. WHONOES

    Stage Line 500W amp repair project

    The transformers in the back of the enclosure don't look big enough for two 250W amps.
  6. WHONOES

    Stage Line 500W amp repair project

    If you have put the + and - wires on the wrong way round, the likelihood is that you have blown the nuts out of all the semiconductors. Before you started all of the dismantling, you should have carried out some basic tests such as check the power supplies to see if one or other is very low and...
  7. WHONOES

    LC parallel tank circuit

    When the L/C circuit is in resonance, its impedance will be very high. This means that it will allow signals at its resonant frequency into the base circuit of the transistor whilst attenuating those above and below.
  8. WHONOES

    Computer speakers power issue

    A common failure mode with these sort of things is that one of the conductors in the lead fractures close to the connector. This often happens after many years of handling. Try replacing the either just the cable or cable and connectors.
  9. WHONOES

    White smoke - Replacing high voltage rectifier caps in PC power source

    Does the power supply squeak off load?
  10. WHONOES

    Help with circuit design of solar powered dog collar

    NiMh batteries have a nominal O/P voltage of 1.2V. A cell is discharged when at 1V. It is possible to peak charge a cell to 1.4V or sometimes even higher.
  11. WHONOES

    555 Timer

    I echo Harald. Please supply a schematic so that we can see what you are trying to do otherwise we are totally in the dark.
  12. WHONOES

    555 Timer

    Indeed it is. Do you have anything particular in mind?
  13. WHONOES

    Power button on PC turns it off right after I turned it on.

    My guess is that a latching switch has suddenly become a momentary switch. If so, the only solution would be to change it.
  14. WHONOES

    can I have some help with measuring hz of an osc with a multimeter

    It's like extracting teeth with this poster!
  15. WHONOES

    What music do you like?

    Have just re-discovered a piece by Percy Grainger 1882 to 1961,an English composer, called Handel in the Strand. Originally called Clog Dance but the composer changed it. It is really jaunty little piece of music of just over 4 mins' long and gets me grinning from ear to ear. There are many...
  16. WHONOES

    What music do you like?

    A friend of mine that I have know since infants school, is a musician who plays drums and bass (not at the same time) and did some session work for Joe. He reckons that it was all done in an old 3 story house with the "studio" on the top floor which was the bit that he rented from the old lady...
  17. WHONOES

    Monster ClarityHD model 1 ... active speaker system ISSUE ...

    As I mentioned in an earlier post, I have an Atlas LCR40 LCR tester. It's dead easy to use. I've had it for many years and it gets plenty of use. See link below. https://canada.newark.com/w/search/prl/results?st=LCR40&scope=partnumberlookahead&searchref=searchlookahead
  18. WHONOES

    Welding Problem: SPOT WELDERS (AMPS, WATTS, VOLTS)

    Sounds like the unit you are describing in post #2 is a stud welder. Stud's / Bolt's are difficult things to weld to panels. These welders use studs with a slightly conical tip that has been copper plated and are made for purpose. The capacitor bank is charged up. Then the panel is connected to...
  19. WHONOES

    Monster ClarityHD model 1 ... active speaker system ISSUE ...

    I wasn't suggesting that the woofer and tweeter were bridged. I was pointing out that there are 4 class D amps in your chip and that they are bridged in pairs to give 2 separate outputs. Don't mess with the filters.
  20. WHONOES

    How to connect piezo speakers to an amplifier

    Nope. Just saying that HF square waves are particularly annoying. As it happens, I designed a cat scarer a few days ago after chasing one through my garden with a Blackbird in its mouth. It runs at 28Khz switched at 1.6Khz. Should be nice and annoying. It's dead simple. I will add it to this...
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