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  1. kellys_eye

    Power jitters

    Any non-resistive load will distort a sinewave. The collective for this is 'harmonic distortion'. It's usually catered for in the system design - so that it will continue to work - but can sometimes create issues with other items connected to the same source supply - which is where you have to...
  2. kellys_eye

    Modified sinewave to pretty good sinewave?

    I don't doubt your determination but in a world where cost/benefit/profit is a priority, no one has 'cracked' what you're trying to do therefore no one will. That is CAN be done is arguable - that it should be or can be done effectively/efficiently is already decided. But it's your time, your...
  3. kellys_eye

    Modified sinewave to pretty good sinewave?

    Short answer - there isn't one. If there was then all modified squarewave 'sine' inverters would be sold as 'pure sine'. Give it up....
  4. kellys_eye

    why spring hook clip multimeter lead are so expensive?

    ...or 'buy cheap, buy twice' as the saying goes. You can purchase the individual probes to make up your own test leads quite cheaply, the usual Chinese source of course. I made up a few dozen in various colours for only a few £.
  5. kellys_eye

    HELLO I HAVE 360 CCTV CAMERA BULB NEED HELP

    The bridge (DB) may well have blown i.e. gone open-circuit which stops the fusible resistor from blowing..... or something else in the circuit isn't working i.e. IC1.
  6. kellys_eye

    How to connect a 5v micro vacuum pump to a Raspberry Pi 4 computer model B

    You can connect 'anything' to a Raspi - most devices (other than LEDs etc) will require some form of buffering and there are many ready-made modules that can be used depending on the device you want to drive. Relay modules will, perhaps, offer the simplest solution as the relay contacts can...
  7. kellys_eye

    HELLO I HAVE 360 CCTV CAMERA BULB NEED HELP

    As ever, fuses blow to protect the system when a fault occurs - doesn't matter if it's a 'real' fuse or a fusible resistor, it's still a 'fuse' and blows for a reason. Replacing it won't change anything - it'll just blow again until the fault is fixed. It's value (I reckon it's 51 ohms) will...
  8. kellys_eye

    Damaged Inductor. Need help and input!

    Given the hundreds and often thousands of parts on a typical board it's surprising there aren't more such examples of failure! This looks to be 'unique' and not one caused by any electrical issue. If replacement restores operation you can put this down to an undetected assembly issue and...
  9. kellys_eye

    Combining Micro Generators

    What voltage? What current? DC or AC?
  10. kellys_eye

    Anyone able to help with this project?

    Don't know about others but I won't open a pdf from an unknown source no matter what......... Post the images direct to this site.
  11. kellys_eye

    Opinions on This Oscilloscope

    There are many reviews on Youtube - split between (very) critical and (mildly) approving depending on your approach to this type of equipment. A professional (or even an experienced amateur) would steer away from this device but as a learning tool it's probably more than good enough...
  12. kellys_eye

    Modified sinewave to pretty good sinewave?

    Damn that maff eh? :D
  13. kellys_eye

    Working around garbled LCD display on a blood-pressure monitor

    Any break in the ribbon connections to the LCD or the PCB will be a real PITA to fix. Such measuring devices as you show are commonly available and not worth repairing (sadly, all too often the case these days).
  14. kellys_eye

    USB Voltage sensors on windows

    Many years ago I used a simple USB joystick interface module to get analog/digital signals into a PC (windoze) called the BU0836. Since that time it has been improved upon but still offers multi-channel input with the simplest access via Wiindoze given its USB joystick simulation: The key...
  15. kellys_eye

    Try to fix Electric Door bell

    Resistors don't generally burn out without good reason so perhaps there's another issue elsewhere? Either way I'd make a guess at it being 27 ohms (a standard value) - it looks like it's a simple dropper resistor - maybe 270 ohms. Can you show how the board is otherwise connected i.e. power...
  16. kellys_eye

    Modified sinewave to pretty good sinewave?

    1hp is 736W and can lift 75kg 1 metre in 1 second (wikipedia). Using maff - 1000kg would be raised 1 metre in 13.3 seconds (1000/75) using 736W and take 40 seconds to reach 3 metres. A typical alkaline AA battery has a capacity of 3.9Whr so three of them would have 11.7Whr. Divide the 736W by...
  17. kellys_eye

    Subwoofer repair

    The technicians response is likely based on the (appropriate) cost-benefit analysis. With an unlimited budget (yours!) I'm sure he'd be willing to do what is necessary but are YOU willing to pick up that bill? This is where a DIY approach is the only reasonable solution. Get it back and post...
  18. kellys_eye

    Superheterodyne wireless transceiver module from core electronics.

    So we have to download all the relevant datasheets (because you can't be bothered to even include them with your query) and read what the manufacturers say just so we can report this back to you? Without being rude, why haven't you done this yourself? We are always happy to help but we expect...
  19. kellys_eye

    Reading data from AT21CS01 using an Arduino board

    If it's powered correctly, connected correctly and addressed correctly and you're not getting the right results then it's FAULTY! We know 'nothing' of your situation/application re connection, power, control etc. This is something you have to fix yourself unless you publish EVERYTHING about...
  20. kellys_eye

    Modified sinewave to pretty good sinewave?

    You never get more out than you put in so using a motor to lift something that drops to generate power is a pointless waste of time/resource although it's neither my time nor my resources so fill your boots! The best situation for off grid would be anywhere you can utilise water flow - hydro...
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