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  1. kellys_eye

    KL MMA160 inverter igbt arc welding machine does not weld although it gives an appropriate value of

    I repaired a 3kW charger/inverter a while ago that used 1N4148's as a bridge rectifier to monitor line voltage (via a low voltage transformer secondary) - one of the diode shad gone o/c and the resultant voltage caused the output voltage of the inverter to be wrong. The images show a...
  2. kellys_eye

    Help

    If your intent is 'torment' them with subsonic audio then you'll be getting far more attention from them if they find out it's you doing it. If you are being 'harassed' then you have a legal standing and should be able to seek legal assistance - have you tried?
  3. kellys_eye

    Can someone please identify what this sensor (?) Could be?

    The connector looks to be a typical sub-miniature coax as might be found on wi-fi antennas or bluetooth antennas. That said is might be a simple 'motion' sensor that can detect over-driving of the speakers or perhaps feedback suppression? Just guessing here - not at all familiar with the...
  4. kellys_eye

    KL MMA160 inverter igbt arc welding machine does not weld although it gives an appropriate value of

    Are the diodes you replaced inserted in the correct orientation? Diodes don't just 'explode' without good cause and something else has quite likely gone wrong that's yet to be identified. Show the area with the blown diodes in close-up plus show the rear of the board where they are situated...
  5. kellys_eye

    Audio Source Switching

    Try a cleaner supply to start with. Use batteries if you don't have a linear regulated supply. SMPS devices are notorious for injecting noise.
  6. kellys_eye

    Audio Source Switching

    What does the datasheet for the device state? Does it indicate the crosstalk figures? It should. The datasheet (which may also have application data added or made available via the manufacturers website) will detail grounding and supply separation/isolation issues if there are any. Often PCB...
  7. kellys_eye

    Have 3,3V need 15V

    What method are you using to control the LEDs? Directly? Simple on-off? Variable brightness? Most users drive them via transistors of MOSFETs - show us a schematic or block diagram.
  8. kellys_eye

    Nakamichi RX-505 Low 12V + and - Rails

    errr... 4.3 divided by 5.1 = 0.843 which, when you divide into 12V = 14.23V......... Clearly the 4.3V zener is the cause.......
  9. kellys_eye

    Trying to mount monitors Please Help

    Most (all?) mountable monitors use what's called the VESA standard which boils down to a 'square' of holes on either a 75mm or 100mm pitch. If your rubber pads are on one of these dimensions then they very much will likely be covering the appropriate mounting holes for a standard bracket. The...
  10. kellys_eye

    DCDC converter output power

    If you have 3.3V out and an accurate load resistor then Ohms' Law can't be defeated. One or the other Volts or ohms) is wrong or your meter is.
  11. kellys_eye

    DSC-P52 digital camera circuit schematic

    The manufacturers 'might' help (in 99% of examples they won't). There seem to be quite a few of those cameras on eBay (used). Far simpler to replace.
  12. kellys_eye

    DCDC converter output power

    Where are you measuring the current draw?
  13. kellys_eye

    UPS with too much boost

    Many UPS devices only have relays and 'taps' on an auto transformer to cater for changes in input voltage. It sounds as if yours has a switching level of around 110V before it 'clicks' to the next tap on the transformer, boosting the output to 134V. Sounds as if you are NOT under any...
  14. kellys_eye

    Portable Power Station no AC port power

    There's probably little/zero information (technically) for this product - pretty much the same deal with ALL electronics these days with manufacturers claiming IPR (intellectual property rights) on everything they manufacture. It's a ruse to stop people repairing rather than replacing. That...
  15. kellys_eye

    DSC-P52 digital camera power button

    The missing track may have had a connection to another pcb layer (it's a multi-layered board, possibly as many as EIGHT layers!). Unless the missing pad passed right through the board and appears on the reverse then you'd have to find out where the pad connects to via the inter-layer connection...
  16. kellys_eye

    Temporary Delay Circuit

    What you need is a monostable. These can be constructed using logic gates or devices dedicated to the task (like the ubiquitous 555) - there are many, many examples across the web.
  17. kellys_eye

    peakelec ESR70 measuring battery internal resistance

    As good as the Peak Atlas stuff might be they cannot compete with the simple 'Chinese' multi-testers. Not sure if anyone has done an actual comparison on them but it would be an interesting exercise all the same. My cheap tester (I now have three - two ordered in error!) does L, C, R, ESR, all...
  18. kellys_eye

    VR5510 PMIC module

    LDO (low drop out) regulators are part of the device and are independent entities that have (or can have) their own source supplies that are separate from anything else. These might be necessary to power other in-car systems that require their own regulated source supply and, being of the...
  19. kellys_eye

    Laptop Short causing weird symptoms

    Generally, a ferrite bead (slipped over a shorting link) will have little-to-no effect on circuit operation in most cases BUT they are there for a reason - blocking hf noise from entering the power lines. Simplest answer would be to replace the ferrite with something similar - it doesn't have to...
  20. kellys_eye

    Potentiometer identification

    Yes, identical.
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