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    0-30 Vdc Stabilized Power Supply

    AN920 A quick question... when you generated (simulated) the bode plots, where was your signal injection point?
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    0-30 Vdc Stabilized Power Supply

    Simulator results are only as good as their component models, and frankly, most aren't great... at least the ones I've played with...MicoSim, SIMetrics, Intusoft & Workbench. While the second two are "cheap" the first two are not. How does the TIP31A introduce a LF pole? It has a 3MHz gain...
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    Transformer design in SMPS

    Is it really that low? If you are doing a planar, or it's a wire wound non-isolated application, seems that that constant would be unusable. On the bench right now I have a interleaved flyback (current mode) 1/4 brick running at 250KHz with planar's (16 layer PCB with 3oz Cu) that uses RM6 N92...
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    Transformer design in SMPS

    Don't forget the winding window area as a factor...
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    9.4V motor driver problem

    No they shouldn't get hot if they are driven properly. Could you provide a little more info... At what frequency are youu running? At what voltage are you driving the MOSFET? A schematic would help... exactly how is your circuit configured "after" the PIC? For 6-7A a MOSFET should work just...
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    SMPS Switch

    Define what you mean by Most modern switch mode power supplies use MOSFET's as the switching elements (I'm not taking about supplies in the KW range). Yes you could "use a sledge hammer to kill a mosquito". There are other things to consider... switching losses for example, larger MOSFET's tend...
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    chip capacitor

    You can't, you have to measure it.
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    Query about batteries

    Check out http://www.amplepower.com/pwrnews/beer/
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    0-30 Vdc Stabilized Power Supply

    Omni Yes tiring if you don't have the answer. Let me reiterate... maybe you didn't read the previous posts carefully enough and missed it before, for the last 15 years of my working career I've been employed as a power supply design engineer, guess what I do... design power supplies!! I am VERY...
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    Determining the frequency of a transient

    Kevin WHAT?????
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    0-30 Vdc Stabilized Power Supply

    Omni Yes, I did "my time" at Northeastern University some 30 years ago (loved that co-op thing... paid for school). I hate to disappoint you, but the IS NOT an industry standard for testing power supplies, it is Agilent's!! While its possible that some schools/courses may have chosen "their"...
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    0-30 Vdc Stabilized Power Supply

    Omni I've been designing power supplies for a living for past 15 years. I am VERY familiar with parameters I asked about. I was just curious as to the knowledge level a one semester class in "Advanced Power supply design and circuit application" gets you. It would be QUITE unusual for the...
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    Determining the frequency of a transient

    Yes, the period of the ringing is related to the time constant of the components causing it. The trick is... what are the components!! Ringing is not considered a first order affect. A large portion of the "values" are probably from parasitics.
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    0-30 Vdc Stabilized Power Supply

    Hello Omni Perhaps you could share with us the results of your "complete" testing? What were your results for things like gain and phase margine, cross over frequency, transient response time, short circuit recovery time, start-up time, line and load regulation, thermal derating... etc.
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    PhotoCoupler PCB hole

    It's for "isolation" of primary to secondary. As isolation voltage levels change so do the creepage and clearances. The opto is often "weakest link" for creepage so you will often find a hole/slit under it.
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    current and voltage out of phase

    The capacitor in a "capacitor start motor" is only there to "start" the motor
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    current and voltage out of phase

    There are different "kinds" of power
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    SMPS question...

    Kevin No!!! A DC-DC converter has a DC primary. You've never heard of a "off-line switcher"? It's still a DC-DC converter on the back end with a AC-DC front end. What do you think the power supply in your computer is??
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    Transformer question

    Guru My comments were intended for Kevin... You mean that the inductive reactance dominates (XL) the impedance (Z). Without a core it's still an inductor (air core) with mutual coupling to another inductor... sure the coupling coefficient is crappy, but it's still "more" than just a piece of...
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    Transformer question

    What is the primary current in ANY transformer? The primary current will be the secondary current reflected to the primary by the turns ratio plus the magnetizing current. Don't confuse reactance with resistance!!
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