Search results

  1. I

    Transformer question

    While I've never designed an iron core transformer, I have designed more ferrite core transformers than I care to remember. Ferrite core transformers are typically 98% efficient. If core losses are any higher, it's considered a bad design. Core loss is a function of frequency and volume (and...
  2. I

    power supply cutting out

    That's not necessarily true. The power supply spec's don't mention what kind of current limit the supply has... constant power, foldback, hic-up etc. True, the supply with the highest output voltage would supply ALL the current until it's voltage started to drop. It's voltage drop would stop...
  3. I

    FLYBACK CONVERTER

    OK... attached is more.
  4. I

    FLYBACK CONVERTER

    There are many factors to consider. What is the input voltage? What is the output voltage? How much current? Voltage mode or current mode? Continious or discontinious? Flyback transformers aren't transformers at all, they are coupled inductors. The number of turns is inversely proportional to...
  5. I

    VR-sensor opamp input conditioner circuit

    D9 is backwards to clamp the negative half of the waveform. Get rid of R9 and move D10 to the other side of R8
  6. I

    0-30 Vdc Stabilized Power Supply

    Hi Kevin Just got back from a 10 day holiday myself. Forget Q3, R19 and 20. That part of the circuit only controls the D12 indicator (LED). It has nothing to do with current regulation or the gain. U3 is configured (when active) like a gain limited integrator. For simplicity just think of it...
  7. I

    OVER-/UNDER-VOLTAGE PROTECTION CIRCUIT ANALYSIS

    Quote from: indulis on February 14, 2007, 02:58:47 PM WHAT WILL THE OUTPUT VOLTAGE OF THE COMPARATOR BE?? It will probably oscillate. Its output will be floating if the load current is less than the set amount of current regulation. Its output voltage will drop just low enough to regulate the...
  8. I

    OVER-/UNDER-VOLTAGE PROTECTION CIRCUIT ANALYSIS

    I don't know what is... either I don't know how to ask a question, you can't understand my question, you don't know how to answer my question or I can't understand your reply. Sorry,to me, your answers don't address my questions. Fine, so the intellectual route didn't work, let's try a practical...
  9. I

    OVER-/UNDER-VOLTAGE PROTECTION CIRCUIT ANALYSIS

    More smoke and mirrors Where do you see a question that asks that you ? For some reason you decline to explain why you think the open collector LM393 works the way you think it does... ... not true, with nothing connected to the output, it either FLOATS, or is pulled down to the MINUS RAIL...
  10. I

    OVER-/UNDER-VOLTAGE PROTECTION CIRCUIT ANALYSIS

    By perpetuating your  "smoke and mirror" answers, you demonstrate your "real knowledge" of the subject!! Those that know, know... unfortunate for those trying to learn. Statements that try to link open loop voltage gain to what level a open collector comparator will go is pure BS!! Rambling on...
  11. I

    OVER-/UNDER-VOLTAGE PROTECTION CIRCUIT ANALYSIS

    Guru I already know the answers to the questions I asked!!! I ask them because of statements like... You state that it's output would try to be 200V? I don't think so...even it were to have a Vcc of 1000V!!! You also imply that it's gain is related somehow to what the output voltage will be...
  12. I

    0-30 Vdc Stabilized Power Supply

    Kevin You say you understand how the "voltage loop" functions... good!! Looking at just the voltage loop, consider the function of D9. It's connected to the U2 pin 3 node, and the voltage at this node is what controls the output voltage. Once the voltage on the the cathode of D9 falls (is...
  13. I

    OVER-/UNDER-VOLTAGE PROTECTION CIRCUIT ANALYSIS

    Explain if you would, how exactly does a "non-linear device" , that would be the LM393, have linear characteristics.
  14. I

    OVER-/UNDER-VOLTAGE PROTECTION CIRCUIT ANALYSIS

    A load resistor?? You  mean pull-up resistor. A "pull-up" supply doesn't have to mean Vcc, and then there is the pull-up value... now explain why you think your "gain numbers" mean something!!
  15. I

    OVER-/UNDER-VOLTAGE PROTECTION CIRCUIT ANALYSIS

    The LM393 is an open collector device!!! guru, you may want to clear up a few things in your statements above, in regards to gain and open collector devices, so that walid doesn't get the wrong idea!!
  16. I

    0-30 Vdc Stabilized Power Supply

    Let's see... how can I explain this... If the output of a device (in this case the opamp U3) can somehow influence the levels at it's input pin(s), it's feedback. Because the voltage level at U3 pin 6 can infuence/control the voltage on U3 pin 2, all the elements in that string are part of te...
  17. I

    OVER-/UNDER-VOLTAGE PROTECTION CIRCUIT ANALYSIS

    The only problem is the LM393 a "open collector" device.
  18. I

    0-30 Vdc Stabilized Power Supply

    kcc You are half right... U3 "looks" like a comparator while it's not active. When U3 becomes active it behaves like a linear amplifier. At first glance, most would call it an integrator. It does have a feedback loop... it's just a "big one" that includes D9, U2, R15, Q2, Q4 and R7. The...
  19. I

    SG3524 buck converter

    This topic was around before but disappeared for some reason... OK... one more time, the 3525 is an "old" PWM. There are better ones out there for buck converters. The last schematic that was posted was also a little different. For starters, pins 11 & 14 should be going to the driver and...
  20. I

    transformer getting too hot.

    AC current through wire that passes through a unknown flux field gives you the frequency based on the number of loops you see?? I've never heard of such a thing... please explain further!! Are you sure your just not seeing the resonant frequency of the wire... like a guitar string?
Top