Questions tagged [pwm]

Pulse-width modulation, is varying the duty cycle of a rectangle wave, usually with a constant frequency.

Filter by
Sorted by
Tagged with
0 votes
1 answer
29 views

Low voltage from simple PWM circuit

I'm attempting to make a simple PWM speed controller for a fan motor. I am powering the circuit with a 12V 10A PSU and have successfully tested the motor directly connected to it. When connecting the ...
user avatar
1 vote
0 answers
52 views

Commutation BLDC Motor with Complementary PWM produces slower speeds than Independent PWM

'"a complementary PWM can be used, which will also reduce the power dissipation in the devices". That means using Complementary PWM makes the MOSFET cooler. However, in my program, using ...
user avatar
0 votes
1 answer
28 views

STM32H7 DMA not transferring correct values into TIM15 CCR1 register, why?

I feel like I am running out of options as to why this is occurring as the RM isn't that accurate to setup DMA + PWM using Timers. The goal is to use TIM15 as a PWM generator running @ 800kHz running ...
user avatar
  • 1,337
2 votes
1 answer
28 views

Control PWM Volume

I am using Arduino's tone() function to produce some basic tunes. However, tone() does not have volume control. I did post about ...
user avatar
0 votes
0 answers
42 views

ESP32 DEVKITV1 - Can't generate waves in two cores

I'm using a ESP32 (DEVKITV1) to generate two waves in two different cores. Below is the code I'm using. ...
user avatar
0 votes
1 answer
88 views

What is the actual operating frequency of a full bridge transformer?

I'm building a circuit from discrete components to run a gate drive transformer to drive the gates of a full bridge DC-DC converter. Before I set the drive frequency and wind the power transformer, I ...
user avatar
  • 151
0 votes
3 answers
64 views

Generate combined sinusoidal waveform (fundamental, 2nd, 3rd...) using PWM

I know that I can make sinusoidal waveform using SPWM, but how can I combine fundamental signal with different frequency signal (2nd, 3rd...) on a single signal created by SPWM?
user avatar
0 votes
0 answers
97 views

Remove clicking from speaker [closed]

I am using an Arduino, in order to code some tune. The arduino uses the tone-AC library. However, when a new note is played, the moment it starts playing, a click can be heard from the speaker. This ...
user avatar
0 votes
1 answer
34 views

Can changing one signals duty cycle in a dual signal PWM create a dead time?

I have a 2 channel PWM which I intend to control a full bridge gate driver setup, however I need to insert some dead time between the signals. Will changing the duty cycle to 1 of the signals to say 5%...
user avatar
  • 1
0 votes
0 answers
45 views

Using resonators to phase-in a PWM

I'd like to have a constant PWM signals, much like this: Wherein the blue trace have centered it's hi at the 0 of the fully rectified AC & the red have centered ...
user avatar
-2 votes
2 answers
70 views

Average voltage in PWM?

I have a doubt regarding average PWM voltage. Let's take a buck convertor with Vin=10V, Vout=5V. With this we can determine the duty cycle of PWM needs to be 50%. Thus means the MOSFET of the buck is ...
user avatar
  • 399
0 votes
0 answers
51 views

Touching or moving LED circuit board causes PWM to flicker momentarily. Without touching the board there is no flicker

The circuit shown is set up as a constant current drive. It turns on and off just fine. When it's fully on the MOSFET on the low side of the LEDs is fully on and doesn't get hot at all and is not ...
user avatar
1 vote
2 answers
84 views

Peak switching power in MOSFET as seen in LTSpice, and reduction using snubber or gate resistor

I am exploring a tentative design to limit current for charging a VFD bus link capacitor from the AC mains. Simple analog current limiters using resistors and transistors are inefficient and ...
user avatar
1 vote
0 answers
36 views

How to generate PWM from based on an AC signal?

I'm working on a project to improve the efficiency of the resonant wireless charging system. For one of the steps to do this, I need to find the phase shift between current and voltage and of \$I_{\...
user avatar
2 votes
0 answers
57 views

Can the output of an L298N be smoothed using a capacitor to reduce buzzing?

I'm running some model trains with a Raspberry Pi using L298N modules to control motor speed. Traditionally, this would be done using what is essentially a DC motor speed controller, but I need ...
user avatar
  • 129
0 votes
1 answer
77 views

Bootstrap circuit for electromagnet drive or sense?

Is there a bootstrap circuit or H-bridge design so that a coil can be energized in one mode (e.g. with an NPN transistor and flyback diode), or sense a changing external magnetic field in another mode ...
user avatar
  • 259
1 vote
1 answer
66 views

Conversion from 0-10V to resistance - Methodology

Summary Finding the most appropriate methodology for converting a variable voltage output to a variable resistance to mimick/replace a thermistor based sensor. Use case/Example There are two equally ...
user avatar
1 vote
2 answers
43 views

Why does slow-decay mode increase torque of brushed DC motor under PWM?

I am working on a project requiring high torque operation of a brushed 12V DC motor at low speed, plus software speed control from a microcontroller. PWM is the obvious choice here. My driver supports ...
user avatar
  • 119
-1 votes
1 answer
43 views

Is it safe to PWM control a consumer smart plug or smart switch?

I was looking at a project that controls the speed of a normal off-the-shelf AC-powered house fan by plugging it up through a consumer smart plug (specifically, the Kasa ones, if that matters) and ...
user avatar
  • 103
0 votes
1 answer
65 views

Cleaning PWM input signal to reduce heating of H-bridge

I'm using a BTS7960 H-bridge to regulate a fuel pump´s RPM. Currently, I'm facing the challenge of extreme heat production. I think the reason is an inaccurate PWM-input signal (picture below.) ...
user avatar
  • 1
-3 votes
1 answer
41 views

How can I change the output pin9 and pin10 into pin5 and pin6? [closed]

...
0 votes
0 answers
14 views

STM32F103: TIMER1 (CH3) doesn't work / produces no PWM (using libopencm3)

I use a STM32F103C8T6 with libopencm3 and I'm trying to get timer 1 on channel 3 (PA10) working. The datasheet (pg. 31) lists as ...
user avatar
  • 157
0 votes
1 answer
30 views

Can someone confirm the typical application circuit of MAX664x Fan controller datasheet?

I'm planning to use the MAX 6644 for a simple fan control application. All in all the IC is very straight forward to use. However after analyzing the typical application circuits in the datasheet I ...
user avatar
-1 votes
2 answers
81 views

MOSFET Driver Base and Gate resistors and other input stage for PWM motor control

I have the below basic pwm circuit for speed controller of a 12V ~10A motor - I have seen this circuit but am unsure of how to select base or gate resistors. These should be to protect the gate from ...
user avatar
  • 5
1 vote
1 answer
27 views

Range of transformer Q variation for UC3844B converter?

Here the UC3844B High Performance Current Mode Controller (at left, SO-8) is used with a custom transformer to step down bus voltage to 24V. The transformer is likely rated for about 40W, so ...
user avatar
  • 12.1k
0 votes
0 answers
21 views

PWM IRF510 Mosfet Current very low

I have a PWM circuit board as shown below that is connected to a water canister. The purpose is to generate hydrogen bubbles. The setup is working but the production of bubbles is very low. The ...
user avatar
0 votes
1 answer
69 views

How will a transformer react to a PWM signal? [closed]

I want to power a 6.3 volt transformer with 115 AC. I will be pulse width modulating the 115 volt AC signal using a PWM controller. Will the transformer react instantly to the reduced duty cycle, or ...
user avatar
2 votes
1 answer
74 views

Need a circuit for switching 200kHz 24V-36V signal [closed]

I need a suggestion for a N-P ch Mosfet configuration circuit that could switch 200kHz PWM signal at 24V-36V. Input for this circuit is PWM signal is MCU 3.3V pin. UPDATE: Load is ultrasonic ...
user avatar
  • 53
0 votes
0 answers
70 views

Controlling BLDC motor with Arduino UNO

I've been working on a project for controlling a BLDC motor using Arduino to send control signals to an ESC, which then will control the motor speed. I'm doing this so that I can test the thrust and ...
user avatar
0 votes
0 answers
46 views

Current measurements for a DC motor being rectified when in reverse direction (differential low pass filter implementation)

Recently for a project I've been trying to capture voltage and current characteristics for a DC motor. To measure current, I'm using a single resistor (R1) in series with the motor, and feeding the ...
user avatar
  • 1
0 votes
0 answers
33 views

How to change the PWM Mode in STM32F407 during runtime?

I have set Timer 8 to PWM Generation CH2 CH2N. Based on the value read by the ADC, I want to change the polarity of both CH2 and CH2N. I have found that using ...
user avatar
0 votes
1 answer
64 views

Does PWM control DC motor's speed or position? How to control DC Motor's position?

The type of motor that I am working with is a 12V brushed permanent magnet DC motor. By following this video by Mr. Paul McWhorter I was able to control the speed of my DC motor by using the ...
user avatar
  • 121
0 votes
0 answers
33 views

Obtaining instantaneous logic level of a PWM signal on STM32

I'm trying to figure out which of two PWM signals that are switching simultaneously is "1" at a given moment. Is there any way to obtain this information?
user avatar
0 votes
1 answer
41 views

PWM solid state relay output not well modulated with inductive load

I am attempting to control the current through a generator rotor by adjusting PWM input to a DC to DC solid state relay (SSR), specifically a TWTADE SSR-40DD. The power supply for the output side of ...
user avatar
2 votes
4 answers
306 views

PWM LED strip dimmer induces noise in power supply

I've developed a PWM dimmer to dim 100W of LED strips. As I dim it to low PWM values, the power supply begins to hum. I have tried to use also higher PWM frequencies of up to 30kHz, but the problem ...
user avatar
  • 121
2 votes
0 answers
108 views

Capacitors exploding on PWM motor controller

I'm part of a project in which we are developing a PWM controller for a 24V DC motor. Our current problem is choosing a capacitor to replace C1, which keeps exploding. We've been running tests at ...
user avatar
0 votes
0 answers
90 views

Higher PWM frequency than rated for device

I've an electronic speed controller (ESC) rated for a maximum PWM frequency of 48kHz. As I was working on a project I was generating PWM. This PWM signal was connected to the ESC. After I noticed that ...
user avatar
2 votes
1 answer
112 views

What does LSB mean in PWM?

I have this PWM exam preparation question in Computer Engineering where it says "What is one V_LSB?". However we've discussed nothing about LSB in the PWM section. What does it means?
user avatar
0 votes
2 answers
72 views

PWM Controlled Current Source to drive 24V Proportional Solenoid Valve using Arduino

I would like to implement a PWM controlled current source to drive 24V proportional solenoid valve using Arduino. What I need are the following: Input will be 5V PWM with 5000Hz frequency, duty cycle ...
user avatar
  • 1
0 votes
1 answer
38 views

AC Motor Control circuit not working in Proteus

I am new to 555 Timers, Triacs and Proteus and I need help to fix a circuit I have built. The intended function of the circuit is as follows. Two 555 Timers are used to produce variable duty cycle 0-...
user avatar
1 vote
0 answers
47 views

ESP32 PWM: How far can it go and how many things can I control per pin?

I am designing lights lights for my fish tank and came up with the idea of using modular pucks of LEDs on small custom PCBs. This modular design would be easily scalable and reusable for future ...
user avatar
0 votes
2 answers
77 views

Logic analyzer gives me much more pulses than expected

Let me start the question by saying that I am using a logic analyzer for the first time, so I am probably doing something wrong. I sniffed the signal that goes to a speaker. The signal is probably PWM....
user avatar
0 votes
1 answer
83 views

Using the WS2811 as a vibration motor control

First of all I wanted to indicate that I am a novice and the solution to this question is probably obvious so I appreciate the readers taking time to leave a constructive comment. I also wanted to ...
user avatar
6 votes
1 answer
82 views

Weird PWM signal if powered by AC/DC source

I've developed a PWM LED strip dimmer equipped with a 230VAC to 5VDC converter and an ESP32 board (schematics below). If I hook up the oscilloscope to the input of the LED, the PWM signal shows weird ...
user avatar
  • 121
1 vote
1 answer
57 views

Mimic a thermistor/variable resistance signal using PWM

I am looking for a way to create a variable resistance signal to mimic the signal that would typically be provided by a thermistor, but by using a digital signal that switches to ground. I currently ...
user avatar
  • 11
0 votes
1 answer
69 views

Can I power a 20.5V DC motor with a 24V PWM power supply?

I am building a coffee roaster using an Arduino Uno and a custom coffee roasting control board known as TC4+. The board has a PWM controller built in. I have a 24V power supply and a motor, which is ...
user avatar
0 votes
0 answers
47 views

Failed to replace HAL_TIM_PWM_Start_IT in an STM32 board

I'm using a STM32 Nucleo board with this manual. The following function I modified in stm32f3xx_it.c handles TIM6 global interrupt and starts a PWM output by using HAL: ...
user avatar
  • 3,420
1 vote
1 answer
90 views

PWM signal generator circuit does not work in real life

I designed the motor soft start circuit in the figure below. I ran the circuit in simulation programs, but when I tried it on a breadboard in real life, I could not get a PWM signal. When I examined ...
user avatar
4 votes
2 answers
141 views

Reducing 8..32V PWM to 5V PWM

I'm a controls engineer specialising in PLC programming. I have a basic understanding of electronics, but I would like to get better and start making some integrated circuit boards for projects. This ...
user avatar
  • 41
0 votes
1 answer
48 views

Driving parallel channels with 1 PWM signal [closed]

I am currently developing a protoboard for an LED driver having PWM control for dimming using a microcontroller. I plan to drive a number of parallel channels of LEDs ('n' number of RGB channels) and ...
user avatar

1
2 3 4 5
49