Questions tagged [pwm]

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

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UC3842 using current sense and Feedback

I am having a few confusions regarding the PWM IC UC3842: I am not able to understand why we have two sensing pins on the PWM IC. The current sense pin uses the current to set up the PWM while the ...
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Seeking Advice for Upgrading Brake Control System with PWM [closed]

I'm working on improving our system's mechanical brake control mechanism. Currently, the brake is controlled by relays, but there are issues with oscillations (because it is a sudden and not smooth ...
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PWM phase shift controller IC confusion

I was reading one of the datasheets regarding the control of an H-bridge i.e. UCC3895. As far as I understand, this is a PWM controller to drive a full bridge inverter. I have a few confusions ...
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How to add an offset to a PWM signal to control a N-channel MOSFET that has a large source voltage?

I want to control a N-channel MOSFET through a PWM signal generated by an Arduino board. The amplitude of such PWM is 0V-5V with respect to GND with frequency 20kHz. My idea is to send the PWM signal ...
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Noisy signal output from BD2320 MOSFET driver

I need help or technical solutions relating to this issue I encountered with BD2320. I intend to use two BD2320 drivers for an interleaved buck converter. One of the channels works well, but after ...
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Zero Voltage switching

I am having confusion regarding the understanding of Zero Voltage switching as given in the website. What does the ZVS do in the circuit shown below? Does it produce a sine wave or it just makes the ...
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Choice of elements for the MOSFET driver (circuit)

Requirements: 600 V, 100 kHz (full-bridge) MOSFET driver L6388E MOSFET - Datasheet Driver circuit (half-bridge): PWM digital isolator circuit: Questions: Cboot is used to power the top transistor. ...
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50 W solar panel and a simple PWM solar charge controller at 14.1 V to keep a 12 V 50 Ah LiFePO4 battery charged?

I have a solid-state PWM charge controller with a regulation voltage of 14.1 V. Can I safely use this to keep a 12 V 50 Ah LiFePO4 battery charged? I understand that the PWM controller is less ...
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SVPWM lookup table

I tried to control the three-phase BLDC motor in the SVPWM method. I use the lookup table for SVPWM. The below one is from saddle waveform (3rd harmonic rejection) which contains 1/3rd period to zero (...
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PWM frequency for braking circuit

I am running a small DC car motor with PWM and I am using 20 kHz. This requires special op-amps with fast v/us times to get a proper square wave out to drive the MOSFETs even with drivers. I am trying ...
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Priority Encoder for PWM Signals

I'm trying to command a DC motor and servo of an RC Car with two signals, one from the remote and one from a Raspberry Pi. I have figured out I need a priority encoder, but there are issues when ...
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Opamp overheating in analog circuit

I'm fairly new to designing circuit boards. I have built a circuit in EasyEDA that takes a 0-3V3 PWM signal from a Teensy4.1 MCU and converts the signal to 0-20 mA current using a low pass filter and ...
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How can I make "50% duty pwm signal" + "flicker signal" circuit? [closed]

I'm new to electrical engineering. I want to make 50% duty pwm signal(adjustable frequency) + flicker signal as following picture. I think 50% duty pwm signal can be made using 555 timer like this ...
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RC Snubber Design Hint for 3 phase AC-AC PWM Chopper

Im trying to design a 3 phase Ac-Ac Pwm Chopper, I'm having difficulty designing the snubber network for the mentioned topology. Now I tried testing this circuit on bench , with my IGBT snubber values ...
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Interrupt function (PIC16F MPLAB XC8)

I have two interrupt functions: one for generation of PWM signal for sinewave generation and the other is for (PWM) generating signal to battery charger. Whenever the supply is available the battery ...
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Connect LED to current limiter TPS259540 and control the current

I have an LED (ILH-ON01) with a forward current (IF) rating of 1 A. I want to operate this LED at a constant current of 1 A using a current limiter. The current limiter I have has a limit of 1.17 A ...
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Buck converter PWM generation issue

I am trying to design a buck converter without using a controller IC. Input 32-52V output 12V, 50W. I don't know how to get the desired duty cycle from the stable 2.5V error feedback. While it is ...
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Wondering how to power this motor (universal motor?) with the correct power supply and using a pwm speed controller

This is a motor that I had lying around and so I did a bit of research and found that it’s most likely a universal motor. As shown, the motor says 120v and 60hz (which I assume is the AC and DC rating?...
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Right Way to Step Down a PWM Signal

I need to control 4 servos using a PLC that operates with 24V. The problem is that servos use only 5V. To accomplish this, I built a simple circuit using some 7805 and a large 1000 µF capacitor to ...
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Unwanted PWM signal picked up in relays

Test setup: I am looking at this relay G5V-2-DC12. The test is simple. I power it up with 12V and connect a PWM signal (0V-5V 125kHz) to the common pin. I probe at the NO pin of the relay, and I ...
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Sinusoidal Current in a Saddle PWM BLDC Motor

I have learned that many BLAC motors have a saddle-shaped phase voltage. Apparently, this can improve efficiency while still retaining the sinusoidal line-line waveform. One reference for this is here:...
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Getting "servo jitter" when trying to move Actuonix actuator slowly. Works fine when going from 1-2 ms in RC protocol

I have a PQ12-30-6-r Actuonix actuator that's moving erratically. When I set the width of the pulse from 1-2 ms then it will move down immediately, and vice versa back up. I can go to 1.5 ms as well, ...
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LED controlled by MOSFET is always on

In my circuit I am attempting to control a LED's brightness via a PWM signal applied to a MOSFET (which then provides power to the LED). This is shown in the image below; power comes in via USB(orange)...
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Power 12V DC Motor with 16.8V (4S Lipo) using PWM control mechanism

I have recently completed a DIY robot that uses 2x 18650 cells (max 8.4V) and a step up module to power four 12V DC motors (Pololu 20d). For my next prototype, I would like to get rid of the step up ...
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Help me find a PWM IC (DP91 1L15 marking) [closed]

I found this 6 pin PWM IC in one of the SMPS. I am unable to find any of its details on Google. Can anyone help me find the name of the device? The marking is something like ...
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Too low output voltage of MOSFET

I'm trying to create PWM-based control system for Peltier elements, but some troubles was appeared. The max output voltage is about 8 V, but I was expected 27 V. The PWM frequency is 50 kHz. And I don'...
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Designing a unipolar stepper driver using STM32 MCU, lack of torque

I am working on my first robotics project which will hopefully become a desktop sized KUKA iiwa. Unfortunately, I have only just completed the first year of my electrical engineering degree so have ...
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PWM Modulator Circuit

I want to generate a PWM signal from a potentiometer. This must be a reliable circuit to be placed in a PCB. I've tried a 555 timer circuit in a breadboard (this one), however, the results weren't ...
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STM32 Timers - how to generate short pulses with long intervals between them?

I have STM32L451 and need to configure TIM3 to generate short pulses (duration is in the range of 1..10 us) and long time intervals (1 second) between the pulses on three PWM channels. The pulses in ...
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Unicorn Mode PMOS For Hurricane Flooded Golf Cart Controllers

We have saltwater flooded golf carts after hurricane Ian. Their old 0-5k Ohm throttle pots are shot, and replacing them is very expensive. The new throttle systems can be fitted more cheaply, but ...
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STM32 STEVAL-Spin3202 Motor control - Issues with driving power MOSFETs with PWM

I've been struggling with my new STEVAL-Spin3202 board from STM. It is using the STSpin32F0a motor driver with STM32F031C6 MCU. The ultimate goal is to control a BLDC motor with six-step sensor-less ...
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Please check if there's anything wrong with my 555 PWM schematic

My first time creating an EAGLE CAD schematic. I want to turn this into a PCB. I want to ask if there's anything wrong with my schematic, like the wiring or the efficiency or something like that.
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PWM with IN-12 nixie tubes [duplicate]

I have some IN-12 nixie tubes and I can drive them using TPIC6B595N chip which has 50V clamping. And this chip has G pin which it is possible to use global dimming. What I questioned is which PWM ...
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ATtiny10 sleep mode

I have a very basic ongoing project that involves 8 LEDs, push-button tack switch with 10 kΩ pull up resistor, and an ATtiny10 microcontroller. The entire system is powered by a coin cell battery with ...
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Please help identify this SMPS IC

I need to repair a charger for an e-bike. The model is SHC-8100L made by stchargers.com. The unknown IC (marked U1 here, a 3x2 mm SMD IC marked 71427) seems to be faulty. Input voltage seems to be on ...
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PWM Charge Controllers: Common types and example schematics?

I started on this quest because I needed to connect my programmable supply (KD3005P) 30V-5A to the PV input of a Landstar 1024B PWM Charge controller to test out the charging functionality of the ...
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Unresolved Issue in MOSFETs-based Variable Load Circuit Design and Simulation

I've been diligently working on designing a variable load for the purpose of testing both AC and DC power supplies. For this task, I have opted for the integration of back-to-back MOSFETs in the ...
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Controlling a 10V PWM LED driver (MEAN WELL HLG-185H-C1400B) with Raspberry Pi

I am working on a project where I need to dim a set of LEDs by utilizing the PWM signal on a Mean Well HLG-185H-C1400B. As a beginner, I am seeking guidance on how to control a 10V PWM LED using a ...
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Is it possible to include a behavioural source in an LTspice sub-circuit for use in a buck converter model?

I'm in the process of modelling a buck converter following the approach in Sam Ben-Yaakov's A unified SPICE compatible average model of PWM converters article in which he models a switched inductor ...
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Converting AC signal into PWM [closed]

I have been attempting to convert an AC audio signal into PWM in order to design a class D audio amplifier. I have made several attempts, but none of them have been successful due to significant ...
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Settling time vs T of PWM Signal

I reviewed this article: https://www.edn.com/a-faster-pwm-based-dac/ where it says the settling time of the DAC will be 5RC (till here we are ok), in which RC=16 T of PWM than if this is true than we ...
Fc3 Fc3's user avatar
3 votes
2 answers
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180 shift PWM signals [closed]

I am a student of electrical and computer engineering and am currently working on a project that involves the study of a multiphase buck converter or synchronous buck converter. I need to shift these ...
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Controlling Flow/Pressure of a Diaphragm Pump

I searched for similar questions; especially this post, but I don't know if the answers apply to my question as well. I am a software guy and have almost no clue about electrical engineering. I am as ...
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Hardware based PWM fan solutions

HPE DL360P’s love to run these fans (8x of them) at max speed. I don’t really need them all running, but wasn’t sure if dummy plugs to just trick the motherboard was a good idea. Wiring length and ...
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LED : Perceived Light Intensity Greater Than Actual Light Intensity (via Weber-Fechner Law)

Background In this question, user @glen_geek posited (with linked references) that perceived light from an LED versus actual light from an LED is greater at lower duty cycles: @kando For PWMing LEDs, ...
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How to make an SDC File

Can anybody tell me how do you specify the values of an SDC file for a digital block design? For example, I have built a PWM using counter and comparator and I need to determine the SDC values, ...
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Bandwidth of a DAC

Could anybody specify what does this bandwidth means in DAC PWM? Source: Designing high-performance PWM DACs for field transmitters (page 2) The bandwidth of a DAC?
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PWM DAC, dividing the 8 bit PWM DAC in 2 four bit PWM DAC [closed]

Can anybody explain what the purpose is of dividing an 8 bit DAC using PWM in two 4 bits DAC and how is it made possible the scaling of PWMH and PWML and how do they affect in total uncertainty. https:...
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The resistor is over heated in my totem pole circuit

This is my totem pole circuit: It works well, but R32 is too hot. This is scope: I changed R32, R34to 470 ohm, but I got the same result: I think the resistor value is the problem. How can I fix ...
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Wrong orientation of a diode destroy a circuit (Schematic included)

I get 24V from the barrel jack. The electromagnet is controlled using PWM. Here, I made a mistake and the diode direction is reversed. (The diode is placed to protect from back EMF.) When I plugged ...
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