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  1. kellys_eye

    What type of OEM screw is this?

    That's a "tri-head clutch screw". Not very common and the tool to remove it likely to be more expensive than cutting it off and re-drilling the hole for a different screw.
  2. kellys_eye

    Power Bank

    At 60mA per LED and 12 LEDs per metre that's a total of 60 LEDs and 3.6A (or about 18W). Running for 8 hours requires 144watt-hours (assuming 100% efficiency) or 160Watt-hours to be safe. The power bank I linked to above will run your LEDs for about 4 hours - but that's on the assumption that...
  3. kellys_eye

    Building a battery powered lamp

    Do some basic tests and calculations first. i.e. how much light you need (there is a required minimum for practical purposes), the capacity of any battery needed to run it for a given length of time, the recharge time you (or your customers) would find acceptable etc. Making them colour...
  4. kellys_eye

    CAN communication using i.MXRT 1064EVK

    Go right ahead. If you are successful you might want to tell others how you did it.
  5. kellys_eye

    Power Bank

    Yes, but what length of strip? A full reel (5m) or something else?
  6. kellys_eye

    Power Bank

    20,000mAhr battery banks are only £30 (UK) - max 20W i.e. 5V @4A output which should be more than enough - buy more than one if you have a problem with insufficient capacity. https://www.argos.co.uk/product/9215346 Building one poses far more issues than just cost (you couldn't build one like...
  7. kellys_eye

    How To Read Spark Time On oscilloscope With High Resistance Probe

    Your first mistake..... Spark timing (duration) is constant however when the spark is initiated does indeed vary with the rpm of the engine. There are 'scopes dedicated to use with engines and they use a pick-up coil to measure the spark and a stroboscopic light to prove the timing. Much of...
  8. kellys_eye

    Design a short circuit protection for +15/-15 and +10/-10 DC power rails

    When I taught electronics, the technicians in charge of the tutoring equipment always socketed the devices that were prone to destruction as they were well aware of both the innocence, stupidity and even maliciousness of students. It's not worth the effort to try to prevent damage as no matter...
  9. kellys_eye

    Beer fridge... Redux

    If this is meant to plug in to your fridge (the onboard diagnostic socket) then you're wasting your time. It would be far easier to obtain a small digital temperature controller and use it to power the compressor and thus bypass all the 'dud' stuff that's currently fitted. Something like this...
  10. kellys_eye

    Not sure where to put this question

    Across switching contacts a value of 10nF to 100nF would seem appropriate.
  11. kellys_eye

    Help needed decyphering a wiring diagram and resistor purpose

    You MUST use a second resistor in series with the sender in order to create a potential divider - the junction of the two resistors being where you will measure the 'change' as one of the resistor values alters (the float moving). Without this second resistor all you are doing is varying the...
  12. kellys_eye

    cd mechanism data sheet

    https://www.manualslib.com/manual/1129108/Sony-Zs-X3cp.html?page=45
  13. kellys_eye

    Not sure where to put this question

    Insufficient transient protection on the 5V rail supply to the logics. Use more capacitors on the 5V supply rail (including lower values) and check you have enough decoupling at the supply pins of any discrete logic gates and/or microcontrollers - such decoupling needs to be right at the power...
  14. kellys_eye

    Kwh meter

    Maybe not frugal but 'gullible' springs to mind - it's the same as the device(s) I linked to on eBay albeit in a fancy box......
  15. kellys_eye

    Help needed decyphering a wiring diagram and resistor purpose

    Oops, didn't see Bluejets post (the one you made the 'ironic' reference to). Yes it was 'ironic' as the wiring diagram isn't what we expect as standard - it's derived that way for 'simple people' (none intended!) who just need to follow a point-to-point wiring arrangement rather than look at it...
  16. kellys_eye

    Help needed decyphering a wiring diagram and resistor purpose

    If you're using a MODERN sender that derives the fuel level from a potentiometer connected across a 5V supply and takes the reading from the wiper (output) then it's a different matter. The original schematic assumes a 'standard' car sender (two-wire). The modern sender will output anything...
  17. kellys_eye

    Help needed decyphering a wiring diagram and resistor purpose

    The 3.5V would only be there if the other part of the divider (the level sender) was connected. With either one removed you wouldn't get a reading. Can't see the actual text (too small) but that pin DELIVERS a 3.3V supply from the onboard regulator and is capable of driving the LCD module as...
  18. kellys_eye

    D&B Audioteknik D12 - Power supply relay issue

    'Input' - meaning the mains filtering section (as per the grey capacitors and inductors) and, potentially, the switch-on thump protection circuitry but if the problem really IS in the power supply section - where it commonly is - we need to see that actual board. A quick check of the output...
  19. kellys_eye

    Kwh meter

    There are many, many modules that can show multiple AC voltage signals (volts, amps, kWhr, frequency - and all simultaneously) and they use an external pick-up coil to measure the current (current transformer) that needs to have the 'hot' wire from the supply voltage fed through the centre of...
  20. kellys_eye

    Help needed decyphering a wiring diagram and resistor purpose

    The 100 ohm resistor and the resistance of the fuel sender form a simple voltage divider. Using the values given (100 ohms, sensor 240 ohms) and the 5V reference from the ESP module supply, the output voltage from the sender to pin 15 will vary between 3.5V (max) and a lower value (assuming 33...
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