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  1. E

    Oscilloscope always showing Sine Wave

    I have a real problem with my scope for any signal i connect it only shows sine wave, even if i connect with some DC source of 12V it only shows sine wave, not sure why. I tried all the methods but of no use.
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    Opamp circuit clarifications

    I am trying to solve the opamp circuit as below (V2 - Vopamp)/1.5e3 + (3.3 - Vopamp)/22e3 = Vopamp / 2.2e3 + C1 * dVopamp/dt ->1 V2 - pulsed input C1 - 14e-9 F 0.66*(V2 - Vopamp) + 0.045*(3.3 - Vopamp) = 0.45*Vopamp + 14e-6*dVopamp/dt ->2 0.66V2 - 1.155Vopamp + 0.1485 = (14e-6)dVopamp/dt...
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    Basic Circuit Analysis

    I have done the same thing Applying voltage equation for Loop1 V1 + I1 * R2 + I2 * R3 = 0 -> eq1 V1 + I1*1e3 + I2*2e3 = 0 -> eq2 Current equation at point "A" 2 + I2 = I1 -> eq3 substituting eq3 in eq2 V1 + I1 * 1e3 + (I1 - 2) *2e3 = 0; -3 + I1 e3 + 2I1e3 - 4e3 = 0; -3 + 3I1e3 - 4e3 = 0; I1 =...
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    Basic Circuit Analysis

    I am trying to solve the basic circuit but struggling to get the result. I get 0.33A and 2.33A but the result from simulation is I1 = 1.33A I2 = -0.66A. What is missing?
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    Digital Input output observing rise and fall time

    Thank you for valuable information i will try with 10X, the oscilloscope is Keysight DSOX1204A.
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    Digital Input output observing rise and fall time

    I am toggling a port but i observe a rise and fall time in digital output the micro used is ST and it is custom board. How do i rectify the issue? The switching is done at every 10KHz. Does it mean the PCB is not proper and has high capacitance?
  7. E

    LR circuit for PWM Input

    One other clarification is Initiating the storage phase for the inductor L by closing switch instant the switch is opened. Now i ask main question in the above diagram there is also ground and it was always told ground is the low resistance path, then current shall go to ground without...
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    LR circuit for PWM Input

    Thank you all for the answers, it is always confusing how many times i read, understood for now that current only decreases does not reverse. The initial thought was when voltage signal is applied the current increases in the inductor, and during the OFF period the inductor had to discharge the...
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    LR circuit for PWM Input

    If i give a pwm signal for the LR circuit with 50% duty cycle, during on the ON time the current will increase and during the OFF time does the current decreases and reverses its direction during the OFF period or it only decreases. My question is mainly on why the current does not reverse?
  10. E

    Flow of Phase currents

    I am writing software (FOC) to spin the PMSM motor, so i am asking the questions i have.
  11. E

    Back Emf Waveforms

    Ok, is it correct to think that C+ A-, A+ B-, B+ C- are the line - line voltages? and the below waveform from other document are the phase voltages A, B, C (with respect to Neutral point)?
  12. E

    Back Emf Waveforms

    Ok, i am attaching the motor data sheet.
  13. E

    Back Emf Waveforms

    When a motor rotates, each winding generates a voltage known as Back emf. Back emf equation is this voltage back emf opposes the main voltage applied on the windings.
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    Back Emf Waveforms

    This is the back emf waveform from motor data sheet I can understand the back emf as A, B and C. But what does C+ A-, A+ B-, B+ C- mean?
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    Flow of Phase currents

    I will try my best to understand.
  16. E

    Flow of Phase currents

    Thank you for the support. But i find difference in concepts when using the inverter to generate sine wave and directly using the sine sources, when using the inverter it is far more difficult for me to understand.
  17. E

    Flow of Phase currents

    I am really confused with phase currents direction of flow, please help to understand i am referring to the below link phase current flow and referring to the diagram and i am using the 3 shunt topology, my main question is if you are using the FOC and SVPWM used we will be imposing the sine...
  18. E

    Phase current calculation

    I was going through the simple foc website open loop there is the below statement "This is very inefficient, as for different motors with different phase resistances the same voltage values can produce wildly different currents. For gimbal motor, you can run it in the open loop with the voltage...
  19. E

    Phase current calculation

    Now i understand it more better the maximum RPM of the motor is 4000, so the back emf generated will be approximately 4k*6.2 = 24.8Volts. But i have one doubt there is only one parameter for inductance How do i get Ld, Lq separately?
  20. E

    Phase current calculation

    Thank you very much the reply, as per the specification i can use the below parameter for the back emf calculation based on the rotor speed i think.
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