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  1. Sunnysky

    That awful "yellow glue" - How to remove it?

    yes a youtube video would be good.
  2. Sunnysky

    That awful "yellow glue" - How to remove it?

    Partial Discharge or PD is from high voltage in dielectrics due to contaminants such as moisture, or voids in solids. Creepage clearance is supposed to allow for surface contamination, but dust can be excessive with moisture which can cause this PD or corona. Clean "it" with good 98% alcohol ...
  3. Sunnysky

    1st Buck Converter Design Help/Advice

    The TI website has all the design tools and layouts. just needs a free registration by email then see main page. enter Vin, Vout, Iout
  4. Sunnysky

    That awful "yellow glue" - How to remove it?

    - unavoidable contaminants in dielectric adhesive are known to cause static discharge internally or PD. If excessive, and visible, we call it corona. Silicone RTV is the best insulation thermally and electrically but not a strong adhesive, more a sealant. Polyurethane is The best adhesive and...
  5. Sunnysky

    12V to 230(400)V without transformer

    150kW @12V is 12,500 AMPs plus efficiency losses. Nice try You would start with a 450Vdc PV array then use synchronous tri-phase bipolar bridge switching with a pseudo-sine wave. A solution for 1% of this power in single phase split 240Vac voltages looks like this...
  6. Sunnysky

    Switching regulator

    oops. I left out important ratio yes it seems 2 equations , 3 unknowns Vin, Vout, R2 if duty is 30% then Vo/Vin=30% But Vo is unknown and controlled by R1/R2 *1.25V hmm. I think your site is not a good reference for Buck regulators.
  7. Sunnysky

    maths for engineers

    n
  8. Sunnysky

    That awful "yellow glue" - How to remove it?

    If this caused arc on HV only, it likely will not cause problems on LV areas.
  9. Sunnysky

    maths for engineers

    upload your images such as ... http://obrazki.elektroda.pl/index.php. in jpg / bump format. this may compress files then paste url upload files button with acceptable extension but not oversized . I use IRFANView to resize images <1MB
  10. Sunnysky

    Switching regulator

    Vout = (R1)/(R2)* Vref just like any Inverting Op Amp gain. (edit) %duty cycle = %Vout/ Vin when used in Continuous (current) Mode see figure 6,7. https://en.m.wikipedia.org/wiki/Buck_converter
  11. Sunnysky

    78L33 regulator

    unless I see full schematic, I cannot advice further.
  12. Sunnysky

    Led's headlight issue

    yes. A bulb has resistance and gets hot, but wears out. A resistor gets hot also and must be larger to run at a lower temp. Trial and error testing would determine the best value, starting around 10 Ohm 5W rating but uses 1.4W. I Have no idea what current is needed to turn off fault lamp . If...
  13. Sunnysky

    Appropriate Oscillator

    another counter, oscillator CD4060 and a cheap crystal @3.5MHz 2 small cap, 2 R's and a MOSFET switch. What is this for? drive current and load type?
  14. Sunnysky

    Led's headlight issue

    Other than finding the threshold for bulb resistance in the instrument panel self test, I think so, or just ignore it. The LEDs work but the lamp fault light is ON. This is a common issue.
  15. Sunnysky

    Signal is periodic or aperiodic

    not "Periodic signal which repeats over and over with repetition period of T"
  16. Sunnysky

    Impedance

    Impedance includes the possibility of phase shift between voltage and current , or a time lag of either current (C ) or voltage (L) Pure Resistance is always in phase. Yet at sufficiently high f, all passive parts , R, L, C have imperfections. Longs leads and coils have L and R, then stray...
  17. Sunnysky

    Signal is periodic or aperiodic

    I agree. Just like how we answer questions like this periodically until a time limit is imposed then it is no longer periodic. Get the hint @vead?
  18. Sunnysky

    Help Identifying a Battery

    I think obsolete
  19. Sunnysky

    Help Identifying a Battery

    I meant the train needs 12V not 2.4 Looks like very non std size A23's fit and 12V but are alkaline
  20. Sunnysky

    Help Identifying a Battery

    those are not 12V which is what you want
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