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  1. dorke

    Sony Bravia KDL-52V4100 Repair Help needed

    Use the KDL-52V4100 Service Manual it should help you.
  2. dorke

    2 transistor circuit input output question.

    Hop, I think the Classic Case should be the " Loaded Wheatstone Bridge". Solving it with Thvenin's equivalent simplifies life a lot.
  3. dorke

    2 transistor circuit input output question.

    Measuring the equivalent resistance,like that: Since there is a voltage source involved you can not do a direct resistance measurement,thus: Measure the open circuit voltage.(Voc) Measure the short circuit current (Isc). From the two calculate Req=Voc/Isc Note:There is never a problem with...
  4. dorke

    2 transistor circuit input output question.

    Well John, If it makes life easier for you here is another aspect of the same thing. Think about the AC equivalent circuit,same thing, replacing the PS with it's internal resistance (=zero). Look at the pics below ,in the AC equivalent circuit ==> R1 is in parallel with R2 and appear between...
  5. dorke

    Question about DC and Coils and LED.

    Well, I misunderstood the way you connected your "circuit". The way you did it ,the Direct Current is creating a magnetic field. You can "Harvest" some voltage out of that magnetic field. This voltage is known as VH (that of the Hall effect). It is far too small for the purpose of lighting up...
  6. dorke

    Question about DC and Coils and LED.

    Connecting the led through a wire to a 9V Battery guarantees the LED is a goner...
  7. dorke

    Question about DC and Coils and LED.

    "am I doing something wrong?" Yes you are,you have just destroyed your Led!:eek: Leds are "lit" by current flowing through them. This current should be limited below the maximum the LED can withstand. The voltage on the LED shouldn't be above the maximum it can withstand. What you did is force...
  8. dorke

    2 transistor circuit input output question.

    Well, We are gradually solving this by breaking down the "problem" to it's "atomic ingredients". So, We are left with the question : " How does a voltage source influence the equivalent thevenin resistance Rth ? It absolutely does influence both Rth and Vth! Here, and in most cases, we take...
  9. dorke

    Triangular signal shift phase

    If I understand correctly what you did. It is only possible if the input triangular signal is a fixed one. that is frequency and offset are fixed and known. Is this the case?
  10. dorke

    2 transistor circuit input output question.

    " theoretically paralleled even though current paths differ" Well, for calculating Rth between points A and B 1) why theoretically ? they are paralleled ! 2) current paths don't matter at all!
  11. dorke

    Need Help finding inductance in a RL circuit

    [ (R2)^2 + (XL1)^2 ]^0.5 / [ (R1 + R2)^2 + (XL1)^2]^0.5 [ (22000)^2 + (XL1)^2]^0.5 / [ (22000+100)^2 + (XL1)^2 ]^0.5 There is an error here: R2=100 thus the 2nd line should be: [ (100)^2 + (XL1)^2]^0.5 / [ (22000+100)^2 + (XL1)^2 ]^0.5
  12. dorke

    Ground and neutral wires

    It is not safe! It is dangerous! You don't wont to lose a loved one, do you!!! Surely there is an authorized electrician somewhere near by... Let him create a safe ground to your house. In most countries the electric-company will not connect a house to the net unless it was checked and...
  13. dorke

    Old Electronics Parts & Diagrams

    I see now, I thought by "desktop" you meant a desktop PC. What do you intend to use it for? A "Variable Lab power supply"? What are the needed Voltage(s) and current(s)?
  14. dorke

    help fixing netgear switching adapter

    This is a classic case of "don't fix it, it ain't worth the time or money" . Just get a new one ,it is dirt cheap,here
  15. dorke

    Old Electronics Parts & Diagrams

    @Brandyn, What kind of Desktop is it? What you describe is probably not an original power supply, some kind of improvisation/replacement . No one builds a commercial product this way!
  16. dorke

    2 transistor circuit input output question.

    Jhon, we are not there yet ... Let's forget all about iB ,the "load", (which btw, can be anything from the Thevenin's-theorem "point of view"). We are left with the circuit in the pic below. While Calculating the Thevenin equivalent we don't care what is/would be connected as a load. The load...
  17. dorke

    Need Help finding inductance in a RL circuit

    o.k. R1=22000 ("horizontal" resistor) R2=100 ("vertical" resistor) L1 on "vertical leg" solve #20 equation as written
  18. dorke

    Need Help finding inductance in a RL circuit

    could you show the details of the set-up. This way it isn't clear to me.
  19. dorke

    2 transistor circuit input output question.

    John, The current through the 5k splits into iB and the current through the 20K . i5k=iB+i20K The situation you are talking about would be like you have disconnected the 20K from the circuit which isn't the case at all.(see pic) The use of the Thevnin equivalent simplifies the calculations...
  20. dorke

    Need Help finding inductance in a RL circuit

    Everything is the same: Z is the same(assuming the same resistance measurements) , Vout/Vin=0.7, f=3.311Hz 0.7= [(R2)^2 +(XL1)^2]^0.5 / [(R1+R2)^2 +(XL1)^2]^0.5 solve for XL1
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