Questions tagged [pwm]
Pulse-width modulation, is varying the duty cycle of a rectangle wave, usually with a constant frequency.
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Servo creates a constant "angle error" depending on its original position
I am trying to set a servo to move to the same angle always when given the same PWM signal. I am using a Savox SH-0262MG. I have an issue when I first move it manually (with my hand) to one of its &...
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Inductor saturation current
I'm trying to determine an inductor's saturation current, I use a PWM with a gate driver (TLP250) and a 0.4Ω sense resistor at the source which I probe across to capture the current waveform.
I ...
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Low-frequency load drive stage design considerations
simulate this circuit – Schematic created using CircuitLab
The circuit above is used to control a 240W ceramic heater by means of a PWM signal, generated by a microcontroller, with 5V logic. The ...
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How to let the robot car turn between 90 to 360 degrees?
The robot car has 3 motors, the first motor is a stepper motor which controls the 2 wheels in front of the car to tell which direction it is moving. The second and third motor is a dc motor which each ...
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PWM controller with synchronous braking
I'm a student and I'm attempting to study how to use two different PWM signals to continuously drive and brake a brushed 12 V motor from an microcontroller.
First frequency will be around 4 kHz (for ...
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DC-DC step down converter frequency isssue
I want to power a heating element (24V,2.5A maximum). I decided to use a push-pull configuration with LM27222.
Here is attached the circuit:
simulate this circuit – Schematic created using ...
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Counter to common believe, Carrier frequency dosn't have to be an odd multiple of fundmental frequency in 3 phase Inverters -- But Why?
According to Dr. Holmes book titled "Pulse Width Modulation for power converters" he states
"First, the frequency of the .carrier harmonic is independent of the
fundamental reference ...
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How do LED drivers with current control work
I'm reading the datasheets of this two LED drivers:
FL7760
STCS1A
The main obvious difference is the first driver requires an external MOSFET, while the second one has the transistor built-in.
But I'...
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How to select external components for a buck converter?
I design a simple circuit activates fan when processor heats up and then control rotation speed. The fan has a brushless motor with an internal motor controller. So I got the idea to create a buck-...
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Converting a PWM signal to reduced constant voltage or constant current output
I'm dealing with an existing circuit that was originally designed to dim incandescent and halogen bulbs from 12V using low frequency PWM. This PWM is visible to the naked eye when substituting a 12V ...
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SMD ferrite beads to supress noise when driving mosfets
I design a simple circuit activates fan when processor heats up.
I started reading more, and I found a very interesting element a ferrite bead in smd form. It has 0.3ohm resistance, Imax 150mA and ...
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How to use SPWM with reference voltage waveforms
I'm doing a simulation for an IM drive in MATLAB/Simulink and Plecs(Blockset). My model is a closed loop system and I generate the reference voltage to be applied across the motor. Now I need to ...
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How to count the number of the generated PWM pulse on ESP32 micropython？
pin=Pin(17,3)
pwm=PWM(pin, freq=freq, duty=duty)
dir(pwm) # ['__class__', 'deinit', 'duty', 'freq', 'init']
How can I count it? Does micropython provide this ...
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Clock Generation with PWM?
I'm designing a device with a central MCU/MPU and two external peripherals. The MCU has an internal clock frequency of 110 MHz. I'd like to use the MCU to generate separate clock outputs for each of ...
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Getting lower output voltage than expected in 5 level inverter
I am making a 5 level inverter using an Arduino Mega. I am using an IRFZ44N MOSFET for switching and also an MCT2E as a MOSFET driver.
The problem I am facing is that I am a getting a lower output ...
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S domain transfer functions of full bridge inverter
I need to design an inverter circuit as in the schema. It is driven by the unipolar PWM method. I have a problem with the circuit. It would be great if anyone can help me.
I want to get the s domain ...
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3.3V to 15V PWM converter
I have the good old problem of converting a 3.3V logic voltage to a higher voltage.
Higher means everything between 12 and 20V. With 15V being used most of the time.
The highest frequency I use now is ...
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Why is the duty cycle much wider than it should be? PIC32MZ & PWM
I'm working with the PIC32MZ2048EFM100 and XC32.
I'm using some outputs as PWM signal generators.
There are frequencies for which the pwm works fine, but not for others.
For example to get 24.4 kHz, I ...
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Circuit of a PWM DC motor speed controller for a 12V 10A DC motor
I saw many circuits for this, most of them were using 555 IC, I wanna use a 12V 15A switching power supply for this motor, so I need a high current PWM speed controller but I don't know how to design ...
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Solution for EMI on signals in a connector?
I have PWM signal and PSU signals coming from switch mode PSU to our machine.
The motor drive boards that run the stepper motors in the machine are located in the PSU.
At the moment the outputs to ...
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DRV8871 (DC-Motor Driver) extremely reduced output voltage
I am working on a PCB which contains a PCA9685 PWM Driver and four DRV8871 motor drivers. The basic idea of the board is the PCA is controlled by a micro via I2C which then creates a PWM signal sent ...
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STM32 - Configure Output Compare Registers on the Fly
since this is my first, feel free to give newbie a feedback :)
I have a following setup with my STM32 Nucleo (simplified, ignore the HW behind):
a) one input signal acquisition (Square wave, consider ...
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Generating variable frequency PWM with Attiny85
Bit of Background: I am currently working with my ATX Power Supply and trying to re-purpose it to use its voltage outputs (3.3V, 5V and 12V). But I would like to have a PWM feature with my power ...
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Replacing potentiometer with a Hall sensor in PWM DC motor control module
I have a DC motor speed controller (PWM) that uses a 100 kΩ potentiometer to adjust motor speed. I also have an electronic throttle pedal that used a 49E Hall-Effect sensor (+5 V, 0.8-4.2 V signal, 1 ...
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Switching a relay with a 5V PWM circuit
I have a coil that has the following specs:
Coil Resistance: 123 ohms
Coil Current: 97.5 mA
Switching Voltage: 14 VDC
I am trying to use a 5V PWM output from an ECU to switch the relay. I know I ...
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Is it possible to measure pwm load current using opamp based high side current sensing?
I am referring this app note, hope to use as unidirectional current sensing for a PWM load
PWM load - load is a resistor,
PWM signal - 100Hz, 150V.
Load current 18mA
Duty 5% (PWM resolution 8 bit)
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Gradually Varying PWM in PSPICE
How do I gradually vary the pulse width in the "VPULSE" model? I tried using parametric sweep but it does not produce the correct waveform or I don't know how to do a parametric sweep in ...
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Raspberry Pi3 - Configure 4 DC motors
I need to feed 4 DC motors of 5V on my Raspberry Pi 3 Model B using PWM (Pulse Width Modulation).
Currently, I have the next components: 2 NPM transistors, 1 L293D integrated circuit, diodes, ...
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What design considerations need to be made to accurately measure current flowing through a BLDC motor due to a 20khz PWM control?
My early attempts to incorporate current sensing onboard a BLDC motor drive operating at 20khz involved the MAX40201FAUA differential amplifier (50V/V) IC and a 0.001ohm shunt resistor. Results were, ...
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Conducted Emissions of EV Charging Electronics
I'm building an AC-charging device for electric vehicles (the standard calls it an "ICCPD" or an "In Cable Control and Protective Device") and I'm facing some EMC issues due to the PWM Signal on the ...
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