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  1. Closed: Re: Closed-loop Stable for Negative Phase Margin?

    The bode blot requires that you consider the 1st crossing of the gain plot, not any later ones, if there is phase margin at the 1st crossing, it will be stable, later crossings can be ignored...
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    Closed: Re: Photocoupler Saturation?

    there is a fair chance your led will eventually die if subjected to unlimited current flow pulses ...

    opto's turn off slowly due to carriers stuck in the base region of the o/p xtor - faster ...
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    Closed: Re: H-bridge gate signal problem

    welcome to the world of RFI ...
  4. Closed: Re: Film capacitor failed in flyback smps at high temperature?

    hi temp = expansion of either type of cap = end termination failure = cap goes low capacitance ....
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    Closed: Re: HEI primary current duration

    certainly you will need soft turn off of the igbt to avoid a spark - if you are calculating dwell periods based on current rpm -
  6. Closed: Re: Why use diff mode inductors rated for 6A(rms) when Input current is only 833mA(rm

    depends on the size of transient you are required to resist - in avionics it could be quite important ...!
  7. Closed: Re: Supply 5V, 5mA from the 240VAC mains without SMPS

    those ckts are risky in that if the fet fails - the following ckts and any isolated wdg's on any comm's transformers go poof ...!
  8. Closed: Re: 300W SMPS with low input capacitance at the end of a 10km cable

    there are standard solutions for 1400V ( + safety margin ) to 60V - and 5 amps out is pretty easy - 1/2 bridge with cascaded devices ...
  9. Closed: Re: Supply 5V, 5mA from the 240VAC mains without SMPS

    yes the mosfet ( or igbt ) has volt and current limit - the big R is to limit the Pdiss of the device and act like a fuse if it goes short - 5W zener on Vout to ensure the fuse blows ... ...
  10. Closed: Re: Why use diff mode inductors rated for 6A(rms) when Input current is only 833mA(rm

    low heat dissipation, high transient capability, - they were in stock ...
  11. Closed: Re: [moved] Why Zener getting heat at no load in Capacitor power supply arrangement..

    because a cap dropper psu circuit is a current source - if you remove the load ALL the available current goes thru the zener - heating it - you have to design for this - unless the load...
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    Closed: Re: HEI primary current duration

    my reply concerned a single coil system - you appear to have misread it ...
  13. Closed: Re: Supply 5V, 5mA from the 240VAC mains without SMPS

    controlled HV mosfet with good sized R in the drainto dissipate most of the power - control mosfet for 5.00V out and 7mA curr limit = pretty easy ....
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    Closed: Re: HEI primary current duration

    for a single coil the dwell time is limited by the rpm, lots of dwell avail at idle speeds - less so at 7000 rpm ( 3500 rpm on dizzy ) as the ignition system cannot accurately predict when the...
  15. Closed: Re: humbucker preamp - j201 gain is 1:1, why ?

    the fet looks like it will be biased off - make sure it is not dead ...
  16. Closed: Re: 300W SMPS with low input capacitance at the end of a 10km cable

    We have done this for subterranean feeds, 1km, 1800 - 3800VDC in, 350V 40A out, knowing the resistance of the feed wires is useful as it is easy to model and see the damping provided - ...
  17. Closed: Re: PI Expert Software and its generated circuit designs

    you can ignore those warnings ...
  18. Closed: Re: Why would a scope suddenly give noisy traces when it never used to?

    broken ground wire some where in the scope probe - this is quite common ...
  19. Closed: Re: Capacitors in input voltage circuit before and after reverse polarity protection

    you have not explained your questions very well and you are asking several questions inside this thread - your graph above may be the result of noise in your measuring set-up - it is impossible...
  20. Closed: Re: Mains Harmonic current limits for 150W offline LED driver

    you are asking us to comment on whether your equipment falls inside a certain specification...?

    - - - Updated - - -

    As yours is a lighting product - there is a whole raft of standards that...
  21. Closed: Re: Current Measure using Current Transducer

    that is quite funny ...
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    Closed: Re: SMPS power stage bode plot

    there is a very slight effect from the capacitance of the power devices causing an extra slight delay due to rise time ( and fall time ) of the switched wave to the o/p filters - this can be...
  23. Closed: Re: Extracting energy from gyroscope precession

    Now you just have to get your head around the swing with no friction is difficult to start from rest ( at bottom ).
  24. Closed: Re: Simple transformerless power supply design

    The OP expressly did not want a cap dropper solution ....
  25. Closed: Re: Extracting energy from gyroscope precession

    I had overlooked work done against the centripetal force forcing the arms and legs out - angular momentum is constant - but not energy - which is supplied by the muscles...

    the precession is...
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