Questions tagged [pwm]

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

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25 views

PWM loop compensation

What is the function of the COMPna pin in the LTM4680?
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Risks of variable power loads on an offgrid inverter (zero-crossing PWM)?

My goal is to regulate loads in my offgrid inverter-powered system. I moved to a fully offgrid house with batteries and a pure sine inverter. I would like to control how much I dump of my solar ...
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Op-amp comparator 0 V - +5 V outputting +1 V - +5 V PWM

I am trying to make a PWM signal for controlling a motor. The TL082 op-amp, connected between 0 and +5 V, takes a triangular input generated by an astable and filtered by a capacitor on the (-) input ...
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Is it possible to modify 8-pin Christmas tree LED controller's functions?

Intro I have an 8-function artificial Christmas tree. The 2-wire LEDs have eight different lighting settings. The control box of the tree has a pushbutton that I can depress to cycle through the ...
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State space model of a PWM driven circuit

I am trying to write down the state space model of the circuit given below: As it can be seen above, a P channel mosfet transistor is driven by a PWM signal. I am trying to model the circuit ...
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How to design mixed signals circuit? [closed]

As a personal project I'm trying to create an RC car. I have decided to use an [SG90][1] servo as a motor (without the potentiometer which will set the motor stop at a certain position) and an ESP8266 ...
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need help to make a speed controller circuit for 775 dc motor

i made this circuit with 555 timer to generate pwm, the mosfet i am using is irf540. But it is not working for me properly, i am getting maximum 4000 rpm without load but my requirement is to control ...
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49 views

Understanding part of TI AN-1839 LED Dimming Schematic

I'm trying to evaluate LED drivers for a project I am working on, and I came across this reference design for the TI LM3402/04: https://www.ti.com/lit/ug/snva342e/snva342e.pdf. The design employs a ...
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>20kHz PWM LED strip ceiling light

I am planning to make a smart controller for ceiling LED light strips inside aluminium profiles. Because of the placement, it is hard to put the power supply unit and controller inside the profile. To ...
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MOSFET PWM issue

I want to dim an LED and have connected a P-channel MOSFET to switch the high side. I added a N-channel MOSFET as a driver. The schematic is attached below. I'm applying a PWM sine signal from an ...
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Why doesn't the voltmeter show the charging voltage when connected to a solar controller's battery connection?

My understanding is, for charging to occur, a solar charge controller needs to output at a higher voltage than the battery's voltage. If so, why, when you test the battery connection of a solar charge ...
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STM32F7 Two Timer Channels Share One DMA Channel

I am trying to write a driver that sends DShot commands to an ESC. I am using an STM32F722 MCU. The DShot protocol is similar to addressable LEDs where 1/3 duty cycle represents a 0 and a 2/3 duty ...
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139 views

PWM control of a water pump with a MOSFET - can't find the errror

I have a 5 V water pump and a 5 V/2.4 A power source. These work together. Now I want to control it with a PWM signal from an STM32 board using a FQP30N06L N-Channel MOSFET and that doesn't work - ...
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Can a PWM solar charger use a battery as the source?

For background, I am slowly migrating from 12v to 24v, but want to use my existing 12v inverters if possible, by having a 12v battery kept topped-up by the 24v batteries. I have a decent MPPT ...
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537 views

Increase minimum PWM duty cycle for high resolution PWM

I'm working on a project involving driving LEDs at a 20kHz PWM frequency with 1024 bit resolution. I've calculated that the minimum pulse time, (1/frequency)/resolution, would result in a minimum ...
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DC motor : dc-dc converter vs PWM

In a cave we are currently exploring, we are currently blocked by a small siphon, we would like to empty into another gallery. For this, I would like to use a 12V pump (not selected yet). As a power ...
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UC3843 PWM Duty Cycle Variation With Temperature

I'm trying to implement a constant current solenoid driver (it's more of a constant wattage pwm driver, current changes with supply voltage which is fine) using UC3843 PWM driver. I'm using the ...
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Cannot generate PWM signal from STM32F40RE

I am trying to generate some PWM signal from STM32F40RE. I configured cube MX as follow: I then set the clock to 72MHz for APB2 where TIM1 is linked with I connected a logic anlyser on PA8 hoping to ...
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Can a servo be controlled (requiring other circuitry) by two binary input pins?

I am working on a project where I would like to control the position of a servo without a normal input, e.g potentiometer. The servo would be constantly powered on the red wire as required, and then I ...
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Query on PI Tuning of Three Phase Inverter

I am working on tuning a PI controller for a three-phase three-level PWM inverter as part of our larger project, but I am facing issues with said tuning using the sustained oscillation method. To ...
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1answer
60 views

What component should I use to regulate power during runtime? [closed]

I have been thinking about a way to reduce heat produced by my resistive wire based on some user input. My circuit is basically a simple resistive wire and arduino, both powerd by Li-Ion battery pack ...
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Reading ADC value of sensor with PWM source

As the topic mentioned, I have been working on getting ADC value of a sensor that is driven by a PWM source. I've come across a situation that when I am getting the ADC value with a rather long time ...
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The optimal PWM frequency of this proportional solenoid

I have to PWM control this proportional solenoid particularly "GP8 036 A59/150" that works on 12V. I tried from 200Hz to 20kHz - it seems that it accepts any PWM frequency with no overheat ...
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How do you check what the highest switching frequency a PWM IC can handle?

How do you check what the maximum switching frequency a PWM can handle? Also, how do you check what the maximum switching frequency a op amp can handle? Because some datasheets don't give this ...
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Would this be an appropriate design for interfacing high-power LEDs with an ESP32?

I am currently exploring a project that allows me to control high-power RGB LEDs using PWM from an ESP32 microcontroller. In this way, I plan to create a simple LED panel for canopy illumination that ...
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High Voltage PWM

I really hope someone can help me with this difficult issue: I want to generate a PWM signal from a 170V DC input. ok, so far I have an arduino that can generate a PWM signal and drive a MOSFET that ...
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Building a flight controller

I am new to electrical engineering and am having a very hard time trying to build my own flight controller. I think I have the basic idea as I am going off someone else's schematic. I am using easyEDA ...
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95 views

Drive N MOSFET with discrete driver at 3.3 V

I would like to drive an N-channel MOSFET that switches a bypass resistor on an LiFePO4 battery cell. The balancing process is done at around 3.5 V cell voltage. A microcontroller, working on 3.3 V, ...
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RGB LED driver, PWMs seem to interfere with each other

I have inherited a project from colleague that is leaving the company. This project is a RGB LED driver with three LEDs, red green and blue, that uses an Elmos E521.36 chip. Its datasheet is available ...
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75 views

1-5 MHz PWM signal generating but how? [closed]

I need to generate a PWM signal that I could change the frequency of it between 1 MHz and 5 MHz. I don't know how to do it. And I have to change the amplitude of PWM between 6-10 V. So I thought that ...
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Controlling a BLDC at low speeds

I want to try and implement a steer by wire system with two BLDCs. The task requires rotating the BLDC at low speeds. I have a 30A simonk ESC as the driver, and an arduino MEGA as the microcontroller. ...
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Sabertooth 2X12 Motor controller unable to control DC motors(UPDATED)

This is a follow from my previous question about the Sabertooth 2X12 motor controller. I aim to control DaNi Robot’s motor using the sabretooth 2X12 controller. After reading the datasheet, a few ...
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Current flow in PWM brushed DC motor drive

I am driving a brushed DC motor (Cytron gear motor) using a gate driver (SN754410) to do PWM motor speed control. My expectation I expected a triangular current wave, ramp up when PWM on, ramp down ...
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How to limit voltage to microcontroller, and drain the rest?

I am designing a circuit to control a set of 0-10v dimmable lights. The lights have two lines, Dim+ and Dim-. Dim+ will be at 10 volts, and the brightness is controlled based on how much is drained to ...
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215 views

P-channel high side mosfet getting hot when not in use

My high side mosfet shown as Q2 in the diagram gets very hot when not supposed to let any current through it. When DIR1 is high and DIR2 is low current is supposed to run through transistor Q1 through ...
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Controlling 0-5V from 0-3.3V PWM pin and 5V power

What I have is I think a standard problem in home electronics but I can't wrap my head around it. I'd like to control an IKEA light chain from an ESP32 board. The chain is basically a set of LED ...
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Using servo motors without PWM

I’m new to the ATmega32 and I want to connect 4 servo motors to a single Atmega32 chip without using PWM pins. Is this possible? If so, how can I do that?
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What does this mean in the datasheet for PWM motor control?

My aim is to control a DC servo motor through PWM. It has a motor controller attached to it that takes in some DC source and PWM for controlling the motors. I programmed/used a myRio (MCU) to produce ...
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Why do I have a sudden current peak when PWMing a valve?

I am driving a proportional solenoid valve with PWM from an MCU as follows: The voltage of the MCU is 3.3 V. The gain of the amplifier is set to 20 V/V. Because the valve consumes 170 mA when fully ...
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50 views

Contrast voltage for display from PWM with negative rail

I want to control the contrast of this display using a well-filtered PWM output. They recommend a potentiometer between Vdd and Vee (negative built-in rail): With my MCU I can generate a filtered PWM ...
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I don't know why UCC27324 getting hot in normal condition

I have some question about UCC27324P MOSFET driver. I have experiment using UCC27324D (8-DIP type) and UCC27324P (SMD type) via this circuit. DIP type driver works fine with no problem same condition. ...
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103 views

Can a 12 V LED dimmer be used with a 6 V incandescent load? [closed]

Can a 12 V LED dimmer be used with a 6 V incandescent load? I'd be interested in knowing what factors make such an arrangement suitable or unsuitable. Specific example: I bought a 12 V, 60 W Dimmer ...
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90 views

PWM average voltage smoothing

I built an ESC circuit. First, I tested it with a drive frequency of 350 Hz; the speed was at about 20 RPS at a 70% duty cycle. But when I changed the drive frequency to 20 kHz, I noticed that the ...
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160 views

Current mismatch in digital constant current source

For an electrochemical etching process I am trying to put together a battery powered, somewhat accurate current source able to provide 1mA to 5mA to a load with a varying resistance. (to be specific, ...
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218 views

How to generate 30 PWM outputs?

I need to generate 30 PWM outputs with a frequency of about 20 kHz. I need to control the duty cycle of each PWM output. It is a bit too much to be reasonably done on a MCU (I usually work with STM32 ...
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What are the caveats in this circuit design?

My question relates to the circuit in the image below. I have a non-inverting amplifier that generally will need to operate as a buffer (voltage follower) after a low pass filter to give a low ...
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This PWM controller appeared to lower Voltage

I use the meter and measure output from this PWM controller https://www.amazon.com/gp/product/B07MK1SKRT/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1 and it appeared that the voltage ranging ...
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1answer
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Help identifying 4-pin PWM fan connector

Does anybody know the name/type of the connector shown below? Context: it is 4-pin PWM fan connector for the fan of an Nvidia RTX A6000. Dimensions: 5mm x 1mm x 4mm, 1mm pitch === Edit === Thanks to @...
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How does a usb heating pad work

Here is a picture of 2 usb heating pads : As far as I can understand, 5 volts come from the usb, go into the curly wires, which produce heat since they are like a long resistor that dissipate power. ...
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Need help making sense of PWM circuit with an Arduino. I do not understand the voltages I measure

As you may have guessed from the title, I am a beginner in electronics so please forgive any absurdity that might follow. I am playing around with powerful COB LEDs and how to drive them. To that end ...

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