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  1. kellys_eye

    PUPS Problems with Uninterruptible Power Supply

    Your requirement is for a power supply that operates from batteries (UPS) therefore the input will likely be DC as storing AC in batteries isn't possible! The batteries themselves will charge from an AC input via a charge/controller. This could be an entirely separate module, not necessarily...
  2. kellys_eye

    Need an expert ardiuno coder with circuit designing skills for my projects at penny's cost

    They're also usually available through established libraries (sketches). What does your system/design consist of? Can you list the relevant 'blocks' (if you don't want to reveal too much detail) or actual operation if you don't mind everyone else knowing?
  3. kellys_eye

    Class B Viking B-2 Transformer Schematic

    Do the BRN and R terminals show continuity to any other terminals? Without getting the specifications from the manufacturer all you can do is power the device up and load the output to the rated level and measure the transformer temperature rise. Transformers from UPS devices aren't usually...
  4. kellys_eye

    EMC/EMI Testing

    If you plan to retail it commercially you have to follow the necessary rules for the country it will be distributed in. Have you checked to see what they are for your location?
  5. kellys_eye

    Superimposing Low Frequency Dither over High Frequency PWM

    ^ fascinating insight - thanks Hop. It's amazing how the violence and destruction of war means the creation of systems that would otherwise never come into existence or be onward-adapted to peaceful tasks. Of course, in war situations, cost never seems to enter into the equation.
  6. kellys_eye

    Cheap Chinese Laser Cutters

    :eek: You don't own a long-haired white cat and have it sitting in your lap, stroking it whilst murmuring "I expect you to die Mr Bond"..... by any chance? Have you checked out fibre lasers? Where the beam is generated off-chassis and fed to the cutting head through....errr...fibres :D I've...
  7. kellys_eye

    Class B Viking B-2 Transformer Schematic

    If the transformer is from an old UPS then the extra windings are commonly used to create a 'variac-type' adjustment that enables the transformer to maintain a reasonably level UPS output voltage (mains) despite a wider swing in input supply. This is referred to as on-line switching where the...
  8. kellys_eye

    Need an expert ardiuno coder with circuit designing skills for my projects at penny's cost

    Happy you took my answer in the manner it was made (as a joke) - some people post on here and have no concept of irony or 'kidding'. But, on a more serious note, do you really expect there's someone that's prepared to help you make money at their own (or for very little gain) expense...
  9. kellys_eye

    Servicing the Daewoo GB14F7T1

    Sounds like a 'gun' problem to me - maybe try a tube restoration machine on it?
  10. kellys_eye

    Can I fix this old Pioneer SR303 Reverb myself?

    ...and TP4/TP5??
  11. kellys_eye

    Cheap Chinese Laser Cutters

    Since a laser cutter is 'just' a CNC machine with a laser head, couldn't you just look for the right mechanism and do a bit of hacking to fit the relevant laser module? The transport mechanisms must be a lot more common under the 'CNC' search result as opposed to a 'laser' search??? As I...
  12. kellys_eye

    PUPS Problems with Uninterruptible Power Supply

    somewhat pointless at this stage but.... the very first Google result (using 'UPS with 12, 5 and 3.3V outputs' as the search term...:rolleyes:) http://connecttech.com/product/xtremepsu-ups-power-supply/ Connect a battery, connect a load. But Google came up with 1.54 MILLION results that...
  13. kellys_eye

    Help with a project idea

    You can store the data internally of the Arduino or externally (EEPROM or SD Card if you want), the choice is pretty much your own. As with anything that you (or anyone) currently may 'lack understanding' in it will be a process of gradual learning. I would suggest that ALL beginners in...
  14. kellys_eye

    LCD display disappears

    The LCD contrast is set by the voltage on pin 3 and if this voltage varies (say under load) then you will see the display go off (or dark if it happened 'the other way'). Your description of circuit operation leads me to believe you haven't got decent enough regulation.
  15. kellys_eye

    MOSFET Circuit Help

    Move the barometer to the OUTSIDE of the case.
  16. kellys_eye

    Help with a project idea

    The basics of this type of project can be found by learning how to drive a dot-matrix display as per this link: https://create.arduino.cc/projecthub/SAnwandter1/programming-8x8-led-matrix-23475a Note that this is not a definitive example but just the first of any number of tutorials on how to...
  17. kellys_eye

    Can I fix this old Pioneer SR303 Reverb myself?

    You have checked the fuses and made sure there is actual power to the unit? As an initial first-test, test points 4 and 5 (TP4 and TP5) should read around +15V and -15V respectively (when measured to chassis)
  18. kellys_eye

    Identifying a chip

    Indeed - but that chip isn't connected directly to the data bus so the fault is still 'on board' and a swap out board is possibly the only way forward. Can you try that board in another slot? but..... can you check track continuity between IC3 pins 11-18 and IC7 pins 8-14??? A close up of IC7...
  19. kellys_eye

    Sony Trinitron screen discoloration

    Looks like a potential physical displacement of the shadow mask - usually caused by someone dropping the set and effectively rendering it unfixable. Unless anyone else can offer some input?
  20. kellys_eye

    PUPS Problems with Uninterruptible Power Supply

    It is 'simple' in the sense that there will inevitably be off-the-shelf power supply circuits to cover your needs - and I'd be very surprised indeed if your requirements weren't met by something we can just give a straight link to! You basically need +12V, +5V and +3.3V - a very common selection.
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