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  • Users: atferrari
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  1. atferrari

    Sheathing material - Right name

    I ve seen quite often, the expresion "gauge", used to name the metallic covers employed for sheathing steel coils for transportation. Is is a right name? Dictionary seems to be of no help here. The material is some 1 to 1.5 mm thick. May I also call it "metallic plate" or what else if not...
  2. atferrari

    LT Spice generating a repetitive signal

    If you like to see how I did it, just download the file "sine 24-steps input.asc" from here: http://www.4shared.com/dir/3379830/4177d351/sharing.html To be opened with LT Spice. Please note that V1 is not PULSEd but plain DC (-1V). Agustín Tomás
  3. atferrari

    LT Spice generating a repetitive signal

    Problem solved using PULSE function. Just 20 minutes calculating timing and done! Agustín Tomás
  4. atferrari

    Low pass filter failing at the lower range

    Yes, links do not work. My circuit http://img374.imageshack.us/img374/5610/lowpasscircuitdk1.png Network not loaded by filter http://img514.imageshack.us/img514/364/unloadednetworkvv4.jpg Network loaded by filter http://img404.imageshack.us/img404/4933/loadednetworkob0.jpg After filter...
  5. atferrari

    Low pass filter failing at the lower range

    The first file is the circuit and the other four are pictures taken when output frequency was appr 77 Hz. Their names are self explanatory, I hope. http://img59.imageshack.us/img59/678...circuitpk2.png http://img261.imageshack.us/img261/7...networkxd7.jpg...
  6. atferrari

    LT Spice generating a repetitive signal

    After reading the manual (yes I do/did!) found that STEP is closer to what I need. And as I said already I just need to find how to employ REPEAT to get a string of steps, repeted forever. Agustín Tomás
  7. atferrari

    Failed soldering test and wonder why..

    Too long a letter! To convey all that you should be able to say it in just one fifth of that lengthy letter. Agustín Tomás
  8. atferrari

    LT Spice generating a repetitive signal

    Hola Keith, I found that even if able to repeat, PWL is not what I need. I think is a step-like function for I want to generate a 24 steps signal following a sine-like law. And that signal has to repeat continuously to test a filter response. See the thread about "lowpass active filter" that...
  9. atferrari

    Low pass filter failing at the lower range

    Please let me ask about this without showing any circuit, YET. There is an active 4-poles Sallen Key lowpass filter. Cut off freq (-3 db) = 740 Hz. Both LM 358 opamps fed with +/- 9 V and duly filtered. At the input, the signal from a network of 12 resistors driven by CMOS shif registers...
  10. atferrari

    LT Spice generating a repetitive signal

    Using LT Spice, how could I simulate a repetitive signal with 12 levels between +2V and -2V? Intention to use it as the input for a passband filter. Initially I tried a voltage cell with PWL output but found that it does not repeat! My fault. Any help out there? I will appreciate that...
  11. atferrari

    Evaluating measurements

    Hola Dan, That will make for ANOTHER file of unknown origin. No thanks. Hola Keith, Thanks for replying. For both multimeters, square wave IS acceptable according to their user manual. My mistake (?) is to show round figures for PIC. Actual difference, at least in theory, is fraction of a...
  12. atferrari

    Evaluating measurements

    I programed a PIC 18F to generate pulses going from 120 to 6000 Hz. Measured the output with two frequencimeters (ME and WA) plus the reading from an analog TRIO scope. In the Excel file I listed following values: PIC: frequency expected at the PIC's output. WA: frequency values obtained with...
  13. atferrari

    Interrupts - Updating timers inside the ISR - PIC micro

    Dan, please reread my last posting (5 Apr). Already cleared that the 1st aprt of mye question was nonsense. Agustín Tomás
  14. atferrari

    Interrupts - Updating timers inside the ISR - PIC micro

    Hola Keit, Your reply made me realize that the jitter DO exists for the interruption but NO for the RC2 pin (clock output) toggling every time CCP1 matches TMR1. What makes the first part of my question, useless. Let's now concentrate on the priority treatment of this. Thanks for your help...
  15. atferrari

    Interrupts - Updating timers inside the ISR - PIC micro

    Hola Mike, Is it your reply intended for this thread? Agustín Tomás
  16. atferrari

    Interrupts - Updating timers inside the ISR - PIC micro

    Time base: 5 ms. Clock at the pin RC2 (CCP1 output) from 120 to 6000 Hz with a duty cycle that could be between 40 to 60%. Xtal: 4 MHz Are these values relevant to my questions? Sorry but I am asking for a conceptual reply. Why not zero jitter? I believe that if CCP1 has priority ensured...
  17. atferrari

    Interrupts - Updating timers inside the ISR - PIC micro

    Micro 18F452 - Working in assembler. I plan to derive timing for two simultaneous processes using: a) CCP1 in compare mode against TMR1 that generates a clock which should exhibit NO jitter due to TMR0 interrupt occurrence (see below). This clock has no 50% duty cycle so CCPR1L and CCPR1H...
  18. atferrari

    Measuring AC parameters digitally - Basics

    Thanks to you all!! Just to reply some of the questions: a - Yes, I expect voltage essentially sinusoidal. Non-liner is the load. Sorry for the confusion. b - Yes, I can increase a lot the number of samples/sec. c - Readings are not simultaneous but consecutives and one of the parameters, V...
  19. atferrari

    Measuring AC parameters digitally - Basics

    AC voltage applied to a non linear load. Using a DSP processor, I digitize the resulting voltage and current along several periods (100 samples per period) and detect zero crossings, so I can calculate: a) Vrms, by squaring each sample, summing all of them, taking its average and finally...
  20. atferrari

    Oscillator circuits

    Lez, I recall reading something describing the pad used in laptops to mimic the mouse action. Suggest to try that in Gooogle or similar. My experience with one laptop in Equatorial Guinea: high ambient humidity created the hell of havoc to the pad. Just in case, keep it mind. Also the...

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