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

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33 views

STM32F205 - can i use a timer to generate a low pulse of specified length

I want a pin to be high by default and then generate two 125-250 µs pulses with 0.1 µs resolution using a command. I was thinking about using TIM1 in one-pulse mode but I don't see a way to invert the ...
0
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1answer
29 views

12v dc motor bi directional [on hold]

im trying to control a motor in farward and reverse direc5ion. The motor is 12v dc 10A motor rating 80.16 W. I have a circuit already built driving a smaller dc motor through my arduino board. Ive ...
0
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0answers
47 views

Reverse engineering MOSFET power circuit

I'm looking at a portable heater circuit that uses a 1.4 Ohm resistive load as the heating element. The circuit in question uses an N-channel dual output mosfet, and on the other side of the board a ...
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0answers
12 views

how can i generate a truncated ramp signal from my pwm signal in labview

i have used the integretor at the output of my pwm signal to make a ramp but the ramp is not truncated.it continuously integratig from its pevios integrated value.how to start the integration from the ...
0
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1answer
49 views

How do I troubleshoot this high-frequency PWM fan control circuit?

I have a 230 Volts fan from EBM papst. It is a fan that can be controlled through a PWM signal (between 1 and 10 kHz). I have built the circuit that is in the manual (see image) I did get this ...
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0answers
85 views

Generating a PWM signal to drive stepper motor

I need to drive a stepper motor with a PWM signal. I am using the Panasonic FP0RC16CT to create the signal. How would I go on about achieving this? What instructions would I use? The signal needs to ...
1
vote
1answer
57 views

H Bridge with PWM input giving small voltage outputs [duplicate]

I designed a H bridge to work with pwm input and to select between directions using a mux; However, when I run simulation, I get an output like this on the oscilloscope; I am using FQP7P06 for the ...
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1answer
34 views

Atmega328 fast PWM (mode 15) on timer 1 not working

I cannot get PWM to work using mode 15 (a fast PWM) of timer 1. It's always giving me a high value of around 4.5V on PORTB2. ...
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2answers
73 views

How to modify a pulse with a very narrow on duty time to a squarewave like pulse?

I have the pulse as seen above. I need to convert this to a pulse without affecting its frequency but modifying its on time. It gives problem when sampling it for some reason, so I need to convert ...
0
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1answer
47 views

PWM or Phase Control Dimming?

I want to dim a lamp around 70W or more using arduino. I have found two ways for doing that. The first one is to make a circuit that "cuts" the sine wave and produce the dimming effect (link). The ...
3
votes
3answers
260 views

Control Power Resistor with MOSFET

I am making a temperature control system using an Arduino. However, I have a problem with controlling a power resistor (which is used as a heater). I was suggested to use a MOSFET to control it. ...
0
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0answers
30 views

12v PWM controller for trolling motor [closed]

I am looking for a PWM controller to increase the efficiency of my Minn Kota 27lbs trolling motor. I was looking for one at Ebay and found these: 40A: 60A: I used a watt-meter and remember using ...
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1answer
68 views

PWM driven bipolar DC motor controller filtered with LC for a peltier element

I want to control peltier element's temperature with a PWM driven bipolar DC motor controller to be able to switch between heating and cooling and also control the level of it. The peltier element is ...
-1
votes
0answers
38 views

12v dc motor forward and reverse, arduino [duplicate]

Im making a project for college (uk). I need to make a 12v dc motor rated at 80.16 watts move forward and reverse. I have got an arduino uno board ( as the microprocessor) I have a 12v dc motor; A ...
0
votes
1answer
37 views

PWM Control of Hotwire Power Supply

I'm building a hot wire setup to do various hobby projects. I've got most of it figured out already, thanks to the wealth of information there is out there. I have a 12V switching power supply with a ...
1
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2answers
65 views

Can i use a PWM HHO Controller to control Brushless DC Motor?

Hi im a electronics newbie. The part im talking about is DC 10-50v 12V 24V 48V 3000W 60A amps DC Motor Speed Control PWM HHO Controller here is the link My ...
0
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2answers
62 views

3 channel 10+bit PWM

I am building a controller for RGB LED strip (12V 5m 5050 LED RGB strip with common anode). My current solution uses Arduino Uno with 3x IRFZ44N MOSFETs to power the strip. The solution is partially ...
0
votes
1answer
19 views

PWM Return Problem

A controller send pwm signal with 2 wires 1- PWM 2- PWM Return But servo motor has 1 input pin. So is it correct to use servo supply return (28v Gnd)or servo chassis input for controller pwm return ...
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2answers
129 views

Why do I need I large resistor to the GATE of my MOSFET?

I tried to control the brightness of a LED using a Linear Hall Effect Sensor fed to an Arduino, and PWM output to the gate of a MOSFET connected to a 12V battery. The LED was flickering a lot, and ...
0
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2answers
64 views

Does frequency equal the number of steps a stepper motor will do?

http://www.thorlabs.us/thorcat/ETN/ZFS13B-Manual.pdf I am supplying a driving PWM signal to this stepper motor. However, I want to specify exactly how many steps to take with this motor. Does the ...
0
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1answer
249 views

Removing ripples from PWM controlled LED in camera vision application

I have made a camera vision setup with highpower LED's which are controlled with a simple NE555 timer and a mosfet. The LED system is lighting up an area where a camera is looking, but unfortunately i ...
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3answers
199 views

How to achieve 57 PWM outputs most easily and cheaply

I need to light up 19 RGB LED strips, which it seems would require 19*3=57 PWM outs and 57 transistors. The transistors aren't an issue, but of course the 57 PWM's is. Most micro controllers simply ...
0
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1answer
66 views

Driving a low resistance load with PWM

I have been trying to build a simple PWM power supply to use a 3.7v battery to drive a small heating element with a DC resistance of about 1 ohm. I have built a slightly modified version of the ...
0
votes
1answer
61 views

What transistor should I use (I need to control 12v 5a)? [closed]

I am searching for a transistor but I don't know which one I should take and the datasheets are confusing because I'm quite a noob. It needs to be able to control 12v 5a with the circuit from this ...
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3answers
90 views

Providing a linear adjustable DC voltage from PWM ( 1.5V to 3.3V)

first of, im not an electrical engineer, so a simple task has me baffled for the last week or so. I am working on project where I am requred to feed a blackbox device with a stable adjustable ...
0
votes
2answers
85 views

How to reduce the amplitude of my PWM signal?

I'm using a PWM control signal that ranges from 0-24V to drive a stepper motor. However, the datasheet in the driver says it should range 0-5V. How can I bring down the amplitude of my PWM control ...
0
votes
2answers
86 views

Mosfet type to drive a 100A DC motor using pwm

I have a bunch of custom made DC motors. They are supposed to work in a range between 80Vdc and 120Vdc. Nominal power is around 800-1000W (they're custom made for a custom application, so specs are ...
3
votes
3answers
384 views

MOSFET overheating in pwm control

I'm using a MOSFET to switch a 24V, 15A load, with the gate input being a 500Hz PWM signal. However, this is causing the MOSFET to overheat and blow. Any suggestions would be appreciated. R1 = 100 ...
0
votes
1answer
83 views

12v dc motor speed control using pwm and h bridge [closed]

I was wondering if yous could lend me a hand with my college project. I have been asked to control the speed of a dc 12v motor. It must go in forward and reverse. See i know i need to make an h ...
0
votes
3answers
50 views

555 Astable Multivibrator Voltage Spikes

I built a 12V LED dimmer based on (modified from) the circuit below. Essentially I used a TIP31C instead of the Darlington pair, and provide power to 555 with 7805. An oscilloscope gave me the ...
1
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1answer
87 views

Control inverter using Arduino PWM output

I'd like to control a frequency inverter using an Arduino Uno board and inverter analog input, in order to control AC motor speed. To do this I need to vary inverter analog input voltage. Inverter ...
3
votes
2answers
129 views

The Transistor Menace - Questions regarding an Arduino rgb LED project

I've been browsing this forum and the internet now for a couple of days and what I thought would be an easy side project turned into a (for me) quite complicated matter. I'm planning to build a mood ...
3
votes
1answer
122 views

Help understanding Low side N-Channel MOSFET driver circuit

I took a simple circuit i found and started modifying it for my own purposes and realized i need to understand it's workings better to get where i need to be. PWM+ and PWM- comes from a LED dimmer ...
4
votes
4answers
1k views

How to reduce 28 V to 24 V under load?

I need to PWM control six 24 V DC fans with a total load of 10.6 amperes. That's easy, right? Just PWM to a few MOSFETs. However, my system voltage is 28 V. At 28 V I'm out of ...
0
votes
2answers
50 views

PWM Drive Simulation

I've been trying to follow an example circuit that does some PWM. First I believe that in a configuration something like this with nor & and that the wave should alternate. Violet line is ...
2
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3answers
76 views

Why does output voltage increase when pwm input frequency to output enable increase?

I'm trying to pulse-width modulate an output from a 74HC585 shift register. To achieve this, I plugged a PWM output from a teensy 3.1 microcontroler into the output enable input of the 74HC595. The ...
2
votes
2answers
73 views

How do I use a PWM unit and/or microcontroller to have transistors progressively all turn on and then progressively all switch off?

How do I use a PWM unit and/or microcontroller to have transistors progressively all turn on and then progressively all switch off? It's for what will most likely be an 18-pulse inverter. ...
2
votes
4answers
77 views

Connecting a galvanometer directly to a microcontroller's PWM output

Is it a good idea to connect a galvanometer (100 µA panel meter) directly to a PWM output of a microcontroller (or any other digital device for that matter)? I set PWM frequency to approximately 10 ...
1
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2answers
180 views

Arduino + MCP41010

I would like to control two 48V DC motors (500W) from electric scooter with my Arduino. I've bought two PWM controllers from eBay and they work excellent. Issue is that controllers have pot on them ...
0
votes
1answer
71 views

Voltage divider on AC current?

I have a 90V PMDC motor with an triac/diac speed controller. Although, I am not sure, the power output is around 90V, but it may be higher. The torque is fairly constant, but it hiccups at the lowest ...
0
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3answers
66 views

Problem : Cmos Circuit

I got a problem related the circuit below. I wanted to make DAC (0-80V) using a pwm input (6 kHz). You might ask why I did not make it with a single n-mos. The reason for it, I used a single as ...
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1answer
48 views

Circuit with reversing polarity and two microswitches

I am building a time-lapse camera slider with the following components 2rpm DC gearbox motor PWM with reversible DPDT switch to reverse motor 2 SPST Microswitches I am trying to wire the ...
1
vote
3answers
77 views

Best way to read 18kHz PWM signal with wide V_pk-pk (5.5-18V)

I am trying to design a circuit for level-shifting a PWM signal coming from a sensor and reading it with a 5V micro controller in an automotive environment. I will run my design by an EE at the end ...
0
votes
1answer
80 views

How to determine DC motor voltage

I am building a new controller for an existing robot. I need to know the voltage to send the motors. I don't want to remove the motors from the robot, but am able to take measurements while it ...
0
votes
0answers
39 views

PWM Chopping current and Decay Modes of motor drivers

This is my first experience with driving stepper motors, so please bear with me. I was looking again through the datasheet of the stepper driver DRV8811 and came across calculations that needed to be ...
1
vote
1answer
69 views

Battery Discharge

I am making a circuit to discharge an 18V Li-ion battery, with multiple cells, in order to condition it. Each 18V cell has a capacity of 100Wh when fully charged. I would like to control the condition ...
0
votes
2answers
55 views

unexplained short circuit with PWM signal?

Something happened that i haven’t been able to explain , I wrote a program to output a PWM signal, this to activate a transistors base using a PWM which I could change the frequency using a ...
0
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3answers
184 views

Controlling a motor using a PWM

Im trying to use a Freescale FRDM-KL25Z, I have been looking at the datasheet to see if I can find the maximum oputput current of the pins with no luck, im assuming its 500mA since its powered via ...
0
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1answer
100 views

multi channel ac dimmer for arduino

I have been looking for a simple ac dimmer circuit to use with my arduino and/or raspberry pi. I have used the TLC 5940 PWM Driver before just to control LEDs and I wanted to adapt this to controlling ...
0
votes
1answer
73 views

Closed-loop gain with source degenerated amplifier

The following circuit needs is modeled with parasitic capacitances to be analysed in frequency. I need to drive it with an MCU that can output a signal that can be some tens of kHz and I need to see ...