Search results

  1. E

    Phase current calculation

    I have seen a 24V PMSM motor specifications and it shows the line - line resistance of 0.57 ohm and L-L inductance of 0.64, suppose i apply an algorithm (sinusoidal etc) and a voltage of 11V RMS at the inverter side, the current that would be flowing is 11/0.57 = 19.29 Amps. It is a small motor...
  2. E

    Inverter Leg Current Sensing

    Please clarify me on the below doubts There are 3 methods of current sensing 1. Inline current sensing 2. Inverter leg current sensing 3. DC Bus current sensing In the Inverter leg current sensing suppose i sample the currents at every 50us for FOC (field oriented control) the currents will...
  3. E

    PWM with 50% duty cycle

    I keep getting questions on how inverter works for different duty cycles. Suppose the inverter has 3 half bridges with 6 switches. If i apply 50% duty with center aligned mode. Then 50% of time in 20KHz the upper switches will be ON and 50% of the time the lower switches and the net result is 0...
  4. E

    Linear Regulator Clarifications

    I wanted to understand is there a mechanism to know if an IC is damaged by checking the resistances between the terminals.
  5. E

    Power Isolation

    I have the following board As shown the board is a single board with some part for microcontroller powered by 5V, there 3 ICs for gate driver which are powered using 12V supply. It works well as long as i do not switch on PWM, but once PWM is on a huge current is drawn from 5V supply and micro...
  6. E

    Linear Regulator Clarifications

    Yes it is AMS1117-3.3. I connected the circuit independently only with this IC still the same behavior. What are the possibilities the ICs are bad around 10 numbers . I am planning to replace with LM series and check the output.
  7. E

    Linear Regulator Clarifications

    As per the theoretical calculation the load is less than 700mA, but i don't know how to measure the actual value of load current. I see now most of the micro pins are floating, does it consume current? Are you referring to 10uF as shown or it is something else? I need to know how to check...
  8. E

    Linear Regulator Clarifications

    I am using the below circuit the IC is AMS1117-3.3V Along with the above circuit i have other micro related section populated on the board. But as soon as i give power of 5V the voltage drops and it does not go beyond 1.2V, the power supply goes to CC mode. How do i find the problem on the...
  9. E

    Hardware issues

    The current is more than the expected and the micro controller gets heated, how long can i micro sustain in heated condition? Can i say a hardware design is good if it works for some days or weeks and then fails, i mean when can i trust the hardware is ok to continue or improvements required.
  10. E

    Hardware issues

    I am basically a firmware engineer but presently i have an emergency where i need to debug the hardware issues. 1. I am seeing several micro controller failures, i reached this conclusion as i could not flash the microcontroller. I wanted to know if i probe the micro controller pins using the...
  11. E

    Testing of currents

    But one difficult problem is, there is an in built opamp inside the micro, so the voltage I give will pass through opamp with set gain(software programmable) and output of opamp will go to ADC. I will try as suggested.
  12. E

    Testing of currents

    If i do the first method what will be the problem? Can you explain please, since as of now i am not successful in reading the voltage properly ADC count properly. I will finally go to the 2nd method.
  13. E

    Testing of currents

    My question is different i have all the differential circuit with opamp, i have written the program to initialize the opamp and the ADC and the micro STM32 family. Now i have to test if the current flowing and the ADC value reading are matching or not. I don't have the shunt resistor populated...
  14. E

    Testing of currents

    I planned to test the phase currents i have board which is partially populated, need to confirm if the firmware is reading the currents properly The Red section is a microcontroller and has in built Opamp which will amplify the signal and then connect to ADC (internal to micro). I created the...
  15. E

    Linear Regulator Clarifications

    I want to convert from 5V to 3.3V using LT1117-3.3 IC, the data sheet is Linear Regulator. I have attached the LT spice model, few questions are, do i need to use resistor or not at the output side, i get 3.3V output in all cases. In the data sheet resistors are used. Please advise.
  16. E

    Hall sensor time out calculation

    It is connected to the micro input pin. I configured it as input capture in software.
  17. E

    Hall sensor time out calculation

    Hall time out is no hall signal from Hall sensor connected to the motor. So, I want to consider if there is no signal (low or high) for 150ms then hall is disconnected.
  18. E

    Hall sensor time out calculation

    I want to measure the speed using the hall sensor, one part of it is to detect hall sensor time out. I want to set around 150ms as hall timeout, that is there is no hall transition for 150ms. So, i wanted to confirm 150ms corresponds to 1000/150Hz = 6.6 Hz? Am i correct or any other factor to be...
  19. E

    Voltage calculations in Fixed Format

    I want to perform the voltage divider calculations in fixed format, please advise if my calculations are correct. Vout voltage is given to the microcontroller, and i want to calculate V1. Vout = V1*R2/(R1+R2) V1 = (R1+R2)/R2Vout V1 = 108/8*Vout = 13.5*Vout -> eq1 13.5 constant is in Q4.12...
  20. E

    H bridge circuit simulation in LTSpice

    Please find the asc file.
Top