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

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30 views

how to resolve mismatch between PWM resolution and sensor resolution?

I have an application that uses a high resolution sensor. The actuation loop runs on this sensor's feedback. Thus, the PWM resolution is limiting my achievable resolution in the actuator's movement. ...
0
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1answer
26 views

DC motor operation with a varying voltage

So I was studying PWM control of DC motors and it got me confused.Here the input is pulsated.This will obviously turn the motor fully on or fully off.Wouldn't this create vibrations?I know pulse ...
0
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1answer
50 views

What is a good microcontroller for PWM signal generation? [closed]

I want to build a Pulse Width Modulation board, something that would allow me to send different PWM signals to the devices connected to the board. My main criteria - is being able to send at least 4 ...
0
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1answer
27 views

PIC reset with PWM

I'm using a PIC18F4550 to control a DC motor with PWM. When I use a PWM of above 50% it works well, but when it starts to go below 50% the PIC resets. I have separated supplies for the PIC and the DC ...
0
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1answer
33 views

Teensy 2.0++: How to get a PWM output from pins OC2A & OC2B

I'm doing a project that requires a lot of PWM's and I've gotten 6 of the 9 PWM capable pins to work, but I'm struggling to get the last 3 running. To get the OC1A-C Pins running a PWM, I did this: ...
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1answer
43 views

Brightness control with PWM dimming LED driver LM3406/06HV

I have an changing input voltage. I would like to feed it into LM3406 and have varying brightness from the Led. So I go through the datasheet. However,the only information and characteristic of the ...
3
votes
4answers
135 views

How to heat up MOSFET within seconds?

I'm using low power MOSFETs (N channel-STP4NK60ZFP and P channel- IRF9530). The aim is to build a demo kit for students to study the thermal characteristics of MOSFET at variable frequencies and duty ...
0
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1answer
37 views

PWM of Diaphragm pump

I'm pretty new in this area so sorry if this question seems foolish. I have a 12V 20Lpm Diaphragm pump that draws around 18 Amps. I'm using it on a home built herbicide spray system to help deal ...
1
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1answer
57 views

ATTiny 841 PWM at 450kHz

I have managed to output 500kHz PWM at 50% duty cycle on PA2 TOCC1 of ATTiny841. ...
0
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0answers
38 views

Controlling a servo motor on an LPC2103 microcontroller

I'm still a beginner on deep embedded systems development. I would like to know how to control a servo motor without using PWM, since I didn't actually learn anything about it on my classes and I'm ...
0
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0answers
52 views

Getting PWM to work on STM32F4 using ST's HAL libraries

I'm trying to switch to the ST HAL libraries and can't seem to get the PWM to work. Compiles fine, just doesn't start. In my main() I call the Timer initialization function: ...
0
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1answer
45 views

generating sine pwm in orcad pspice

I am trying to design a PWM inverter in Orcad PSPICE where i am using a Vpulse source from library to generate MOSFET triggering pulses for H-bridge and it works fine for square waves. But i if i ...
0
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2answers
23 views

relay for USB camera control

I need a little help with some electronic components: From my RC system a I get a signal which is 3.3V PWM, 5 volt and GND. I need to make a 5V PWM out of this for my camera. PWM values are ...
0
votes
1answer
51 views

How does PWM work on an Xbee Wi-Fi Module S6B?

I've read that the PWM on an Xbee is 15625 Hz and that it is somehow different from the PWM used to run motors. What is the difference? Note: The XBee PWM is not the same type of PWM used for ...
0
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0answers
25 views

Control of a single-phase PWM inverter

When designing a controller for the canonical DC-DC converter, I found a good number of models (linearized transfer functions) that could be used to design a compensator. I am attempting to do the ...
1
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0answers
50 views

DC/DC Converter MOSFET switching

I am currently building a SEPIC converter. The signal arriving from the MOSFET driver to the MOSFET seems all good, however the Vds doesn't seem to follow the drivers signal and it makes the MOSFET ...
2
votes
3answers
125 views

Debugging when oscilloscope grounds cures the problem

In a nutshell : My circuit behaves erratically I connect the 'scope to find out why The problem disappears In particular, this concerns the circuit in my last question although this is not ...
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votes
1answer
67 views

how to convert digital signal(PWM) into analog signal [duplicate]

analog signal can b easily made by using PWM in micrcontroller but it is not a real analog signal. please tell me how can i convert PWM into real analog signal
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1answer
106 views

Constant current driver - direct pwm dimming

I recently picked up a cob bulb of Ebay that came with a constant current driver. Tried to dim it using a mosfet and PWM signal of an Arduino, but it resulted in a very loud ringing/humming from the ...
3
votes
2answers
81 views

What's a good set of PWM values to make sine waves for a 3 phase motor?

I'm building a synchronous rotating spark gap for a tesla coil. I have a working mcu (Kinetis K64F) driving a 230volt inverter board and it spins a 3 phase synchronous motor. The motor is a ...
0
votes
1answer
69 views

What is the harmonic content of a PWM signal?

Suppose I'm using a 3.6 kHz carrier to reproduce a 60 Hz sine wave. To properly design a filter for this application to hit a specific harmonic distortion target, I need to know the harmonic content ...
2
votes
1answer
86 views

Signal on top of PWR line

See edits at bottom: I'm trying to design a network of circuits (see example below), in which a modular circuit (non-static, can be change, with high variability in current draw) is connected on any ...
0
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1answer
85 views

Driving IR LEDs using PWM - measuring current & current source questions

For a project I'm currently working on, we're trying to drive 940nm IR LEDs (Kingbright L-934-F3C) using PWM, regulated by an Arduino Uno. We've run into several issues during our prototyping process ...
0
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0answers
49 views

How to discharge a capacitor quickly…(filter of an H-bridge/inverter)

I have used four IGBTs to build an H-bridge… the inputs of the h-bridge are SPWM and are programmed in a way as shown below: The output of the H-bridge is a three level pwm(as expected), and then its ...
7
votes
3answers
793 views

Why do RC applications use such a small PWM duty cycle?

I know that RC applications, such as a drone, use PWM signals to drive the motors. This PWM signal is mostly 50 Hz (0.02 s). The pulse itself varies from 1 ms to 2 ms. So a ...
17
votes
4answers
1k views

How to clean up a noisy signal?

I'm controlling a 4-pin PWM PC fan from a PIC16F684 with the fan speed driven from an ADC reading of a proximity sensor. This all works ok. I wasn't originally planning to use the tachometer output ...
0
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0answers
29 views

Integral cycle (PWM) control of AC voltage input to heater

I'm designing an open loop voltage controller for my water heater element. I'm planning on using a triac and controlling it using integral cycle control. There is no temperature sensor feedback , just ...
0
votes
1answer
62 views

Problems with IGBT driving

this is my first question, so please be patient with me :-) The problem is with IGBT we are using, IRG4PC40S datasheet available here> link It has to control a 1kW heat block to keep a temperature ...
0
votes
3answers
88 views

How do I use pin5 to control duty cycle of a 555 based PWM?

I have built a simple PWM using a 555 IC to drive a motor for an optical chopper and I want to be able to use the output of the chopper signal as a speed correction feedback for the PWM. I think I ...
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votes
1answer
40 views

Current Source version of TLC5940 (current sink LED PWM driver)?

Is there a current-source equivalent of a TLC5940 (current-sink) PWM LED driver? I'm working with a large number of linear resonant actuators (LRAs), each of which only uses ~50mA, but must be driven ...
0
votes
0answers
39 views

PWM lithium-ion charger

I want to make a custom lithium-ion 18650 standard cell charger as I will be charging 100s of them (recycling old laptop batteries). Base on my research, lithium-ion cells use constant-current, ...
0
votes
0answers
71 views

what are the standard ways to generate sine wave using Hbridge and micro controller?

I'm in to driving an h-bridge made of two ir2110 and the pulse width modulation(pwm) signals will be provided by the micro controller. I did some some groundwork to understand how sine pwm is ...
6
votes
1answer
170 views

Why does my PWM amplitude vary with duty cycle?

I'm controlling a 4-pin PWM fan from a 5V PIC and before going too far I'll say that everything is working fine but I'm just not understanding what I'm seeing on my scope. The fan has a 12V supply ...
0
votes
3answers
189 views

AVR/Arduino: Output 2 pwm waveforms with 90 degree phase shift

So far, I was able to get two outputs at the correct resolution (35kHz-75kHz at a resolution no worse than 0.7 kHz) using the code below. I'm wondering, now, how I can get a phase shift between the ...
0
votes
2answers
94 views

LM317 and PWM grounds

I have a question regarding the LM317 and PWM. My circuit receives +12v and has three grounds (R,G,B) that are PWM. I need to drop the voltage down to 3.2 volts from the 12 volt source. NOTE: I know ...
4
votes
4answers
381 views

Rc network placing R before C vs after

simulate this circuit – Schematic created using CircuitLab Using a rc network to smooth a PWM signal from a microcontroller, to a true analogue voltage. What will be the effect of having ...
0
votes
0answers
48 views

Convert voltage to Resistance

I have a constant current source output, how can I convert this to a voltage with another voltage as reference. Electronically not theoretically with math? I will have an output of +3.3Vmax from a ...
1
vote
1answer
107 views

How do I use 5V PWM from PIC to control 12V fan?

I'm not sure if that title explains it well enough, but I have a 12V PWM PC fan which I want to drive using a 5V PIC. The fan has 4 pins, GND, +12V, PWM and TACH. The TACH is a speed sense pulse from ...
0
votes
1answer
72 views

Motor noise interfering with I2C

I built a robot using the Arduino Due with all the sensors running at 5V over I2C. There is a level shifter on both I2C lines. The motors are controlled using a VNH5019 motor driver carrier from ...
7
votes
2answers
655 views

Controlling a very small DC motor with PWM?

I have a very small DC motor (from a Walkman), I would like to control the speed from a micro-controller. For that I would like to connect a MOSFET in series and apply a PWM signal to its gate in ...
1
vote
2answers
73 views

open-drain reliability problems

I've built a run of simple boards like the one shown below to control LEDs in automobiles. The boards have twenty of the NX3008 mosfets in an open-drain configuration as shown, which are controlled by ...
0
votes
1answer
99 views

Other ways to vary voltage besides PWM [closed]

I am trying to control an electronic throttle, the ECU (Pi Innavo M220) I am currently running allows for PWM, but several other components are already drawing a lot of power. The M220 Has digital and ...
0
votes
2answers
59 views

How to calculate the RMS of an AC PWM?

I am looking at a servo, which is driven by PWM. The PWM signal itself modulates NOT DC but a sine AC, so when Throttle is set to 100%, I can see a rather nicely drawn sine wave. But when Throttle is ...
0
votes
1answer
70 views

Variable vin AC to fixed DC power supply design.. Simplest And Small

Okay, so bare with me on this one please... First post on this stack and still refreshing my memory on electronics in general. So basically i'm working on a project which generates a varying AC ...
0
votes
3answers
42 views

PWM module and inrush current from motor

I'm trying to setup a power feed for a milling machine using an old DeWalt drill motor. I've got a 13.8v 20A power supply and a Kemo M195 20A PWM module. My concern is the inrush current from the ...
1
vote
3answers
51 views

How to do PWM with least ripple in software?

I'm interested in generating a PWM signal in software on a micro (it is not possible to use hardware PWM in this case). It is simple to use (for example) a loop with a counter that counts to 255 and ...
0
votes
1answer
43 views

Double VCC across motor

I have a motor which runs in only one direction when excited by a square PWM at 500kHz with a voltage of 5.6V across the two pins of the motor. Consumption is around 100mA. I have a 1.8V square ...
0
votes
2answers
154 views

Arduino PWM control MOSFET

I have a bit of a problem that in hoping someone can shed some light on. I have a 4 wire fan (from a power mac g5) and I found that the pinout is positive, negative, PWM and rpm output. It's a bit ...
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votes
1answer
55 views

How to controlle a motor with arduino

I have 2 og those 12v motor and a 12v battery http://www.enigmaindustries.com/Motors/Bosch_EV_Warrior.htm I want to know what s the best solution to controle the motor with an arduino Uno. Is the ...
0
votes
0answers
48 views

Trilevel PWM for H-Bridge, potential shortcircuiting in inverter

Here is the schematic I have followed, mine is not exactly the same, but for the most part, it follows the same method, generating a sine and triangle reference, generating a square wave and then ...