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  1. kellys_eye

    Overdrawing an analog ammeter?

    LM317 and one resistor - sorted.
  2. kellys_eye

    Reading a ruler help, 1.2 or 1.02

    :rolleyes:
  3. kellys_eye

    Modular Controller build with Arduino (Teensy 3.5)

    You could use an analog input line using different resistor values for each switch and then just do a calculation to determine which has been pressed. This doesn't allow for multiple button presses where confusion would reign.
  4. kellys_eye

    Overdrawing an analog ammeter?

    If your power supply is properly designed it would have current limiting at the rated output and thereby offer built-in protection to the metering.
  5. kellys_eye

    Enlarging hole in reflector?

    Isn't the reflector designed to have a 'focal point' that you're effectively moving by removing plastic? With a new bulb improperly positioned you won't get the designed beam pattern/width whatever....
  6. kellys_eye

    Ft101zd frequency counter help

    http://www.radiomanual.info/schemi/FT101ZD_serv.pdf section 5-25 onwards. It will actually TELL you the value!
  7. kellys_eye

    Ft101zd frequency counter help

    The manual/schematic for the radio is generally available. Do you have it? Can you identify it from the component listing therein? There is nothing we can use for size reference but it looks like a standard polystyrene capacitor of 330pF to me - one step lower than silver mica for accuracy and...
  8. kellys_eye

    DC powered devices

    Assuming the polarity IS correct there is no reason why the devices shouldn't work correctly. If they are blowing fuses then you ARE doing something wrong. They should easily tolerate 12V +/- 10% (so 10.8V to 13.2V)
  9. kellys_eye

    Vintage Schematic Questions

    Another important point to note is the potential for a LIVE CHASSIS situation as the wiring from the mains supply can be crossed without affecting the operation of the equipment - other than making touching it potentially lethal! Do not use a non-polarised AC mains plug. Use one with an earth...
  10. kellys_eye

    Interesting PCB production method

    I suspect there's a similar bleed between pixels in the process I linked to. Certainly the board that was shown produced didn't have any of the usual raggedy edges tat a dot matrix method usually produces.
  11. kellys_eye

    Interesting PCB production method

    Caught a Youtube video the other night of a PCB manufacturing technique that impressed me. It was based on covering the copper board with photopolymer daylight resin as the etch resist but the 'clever' part was using an LCD panel as the transparency. The LCD panel was stripped down to its...
  12. kellys_eye

    Computer electronic component problem?

    Poor soldered joints in the power supply could be a definite cause - the pops being caused by sparking across the joints under high load. Could also be a case of a loose power input lead (common). Incorrectly seated multi-way power plug to main board? Best check for loose connections and, if...
  13. kellys_eye

    7240PE Q427, Q428, Q429, Q430 - part substitutions

    Personally, unless identical replacement parts can't be found, I'd use OEM parts to repair the unit and try to maintain its provenance - such equipment can, if it hasn't already, achieve cult collector status and appreciate in value considerably. As for protection - fuses to protect...
  14. kellys_eye

    7240PE Q427, Q428, Q429, Q430 - part substitutions

    I agree that many devices are built 'down' to a price rather than 'up' to a specification (quality) but until the original demise of the components can be determined, fitting 'larger' ones won't help. There are many examples of where parts replacement to increase longevity may be appropriate...
  15. kellys_eye

    7240PE Q427, Q428, Q429, Q430 - part substitutions

    How? Your method is akin to fitting a larger fuse when the original (properly rated) fuse has blown. Manufacturers spend many thousands of hours/dollars on designing a system PROPERLY so why would they specify 'poor' parts? Have you discovered WHY the original parts were toasted? If...
  16. kellys_eye

    Makita polisher not working

    Have you checked the fuse on the plug (assuming there is one fitted)? Check the mains input lead carefully along its length for cuts/breaks. Measure its continuity from the plug 'live' pin to the brown wire at the switch - do the same for the blue wire. If you get continuity on both then...
  17. kellys_eye

    Camera LCD Fault, FFC/FPC Connector Cause?

    Clearly the black plastic 'lever' - the one that secures the flat ribbon and ensures good contact - has been damaged therefore not all contact points are being appropriately 'squished'. It may be possible to purchase an identical connector and swap the black plastic pressure strip - it only...
  18. kellys_eye

    What are these?

    Transient suppressor - rated at a value to limit either the output being over-voltage or to protect it from an externally supplied voltage exceeding its rating (capacitors on the output terminals). If it's shorted then it's done its job! Replace with suitably rated equivalent if you can't find...
  19. kellys_eye

    Electronics for prop control

    So sorry to hear of your personal health issues Hop - I wish you the most successful of recoveries and a calm and relaxing holiday period! You most certain do have an interesting past history in electronics and its nice to read of your skills being requested to renovate that old equipment -...
  20. kellys_eye

    Mystery Electronic Device

    Well we're just clutching at straws here. You'd think that someone with the title 'Etech' might have just made a few more intimate tests and passed on some relevant information. The light test, a 'sniff' test, a resistance test.... opening the bottle even. Subject to the OP revealing the...
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