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  1. kellys_eye

    Help!! Control module diode identification

    I know...... I did. It's not relevant. ...but as my next post asks - 'what was the fault that CAUSED the diode to fail?' As with fuses, you don't just replace a blown one without finding out what caused it to blow in the first place. And with a suggestion to fit a 'higher rated amperage'...
  2. kellys_eye

    Circuit Element for variable current control

    Most 'loads' draw the current that they need and no more - paralleling supplies will increase the total current supply capability. e.g if you have one power pack that delivers 1A and another that delivers 0.5A (both the same voltage) you can parallel them to get a maximum of 1.5A. If your load...
  3. kellys_eye

    Getting Signal Voltage From Source Power

    0dBm - 1 milliwatt
  4. kellys_eye

    Help!! Control module diode identification

    Regardless of the diodes current status (bust) they don't 'bust' without a good reason and given it's a 3A+ diode then 'something' made it go bust that way. Unless you find out what it was that caused it to fail then replacing it will just cause the same thing to happen - and if you fit a...
  5. kellys_eye

    Optimus CD-7200 Missing Lens

    As far as spare part for laser assemblies goes I believe they are sold 'complete' and that alignment of such parts is so critical that individual elements of them are not generally available. Have you looked for a replacement laser assembly? Got a part number for it?
  6. kellys_eye

    Help!! Control module diode identification

    What makes you suspect it's broken? Do you have a complete wiring schematic for the tractor? Is there a particular fault that manifests itself as the diode being the cause of it?
  7. kellys_eye

    Bush Dab radio keep turning itself off

    Have a quick look inside the unit - I believe the main control board is a plug-in module and it can come loose if the radio is knocked.
  8. kellys_eye

    current limiter for dual rail power supply.

    The data sheet for the LM317 contains all the info you need to get a simple fixed or variable suply going. The negative rail version of the device is the LM337 - equally popular and easily available.
  9. kellys_eye

    High power nema 11 stepper motors

    You can certainly get high speed motors with significant gearbox reduction to give the torque needed - there are many suppliers that offer encoder add-ons as extra too although it's simple enough to put your own on.
  10. kellys_eye

    Help!! Control module diode identification

    Have you determined its cause for failure? Such diodes are usually robust and withstand a lot of abuse.
  11. kellys_eye

    100 Amp Variable Buck Converter

    The usual method is to parallel their operation as the difficulty is finding the ferrite cores that won't saturate under such loads. AFAIK no one manufactures cores that are big enough to cope in one go - with the potential currents involved, a single-core solution sounds dangerous anyway...
  12. kellys_eye

    Test Equipment

    Second hand test equipment is the only way to go when starting out in electronics - unless you have a limitless budget of course..... and 'any' 'scope is better than no scope as far as learning is concerned. I have heard and read of the Rigol hack and actually approve! I find it...
  13. kellys_eye

    current limiter for dual rail power supply.

    The LM317 is easily configured as a current limiter (one resistor) and can be fitted 'in-line' with your regulator output. You can even fit switched resistors to have 'variable' limiting. In fact I'd use LM317's throughout for simplicity and ease of purchase (multiples cost less, output is set...
  14. kellys_eye

    High power nema 11 stepper motors

    The best I've seen for NMEA 11 is as low as 0.1Nm - unless anyone can do better? Have you considered usiing a different type of drive motor with shaft encoder? servo motor-style?
  15. kellys_eye

    Adding accessories to component systems

    @duke37 - I admire you wading in to comment...... I read the OP and just 'walked aways shaking my head....'
  16. kellys_eye

    Test Equipment

    What have you got? What would you like? Buy or build? We could (should?) have a discussion on test equipment - is there a sticky post on it? - but this thread is just an opening shot to see how people feel about the stuff. I'm in the market for a new DSO (budget range, I'm not into hi-end...
  17. kellys_eye

    CPL Load analysis

    Much as modern active load circuitry I suppose.... MOSFET load (power dissipation) device(s) with source current sense resistor generating feedback signal to comparator with set-point voltage (load) determination. You could chuck in temperature compensation if necessary.
  18. kellys_eye

    Fidget Spinner Generator :)

    Nothing particularly 'new' about the method - it is, after all, just a 'generator' operating on the same principles of all generators. It won't be any more efficient either.
  19. kellys_eye

    Oscillator

    Guessing he's after making an echo sounder - 200kHz being a common transducer frequency.
  20. kellys_eye

    Why do they print brown letters on black chip packages?

    Yes, laser engraving is the reason the print is 'brown'. There's a trick going around where you smear a VERY tiny portion of white silicon heat compound on the chips and it 'reveals' the print a lot more clearly if it's a particular issue for you.
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