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

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29 views

How does this motor drive circuit work?

The Drive terminals are connected to a PWM signal generated by an arduino micro controller. The purpose of this circuit is to isolate the arduino from the motors to avoid too much current being drawn. ...
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27 views

STM32 - Multiple channel PWM input

I am using an STM32F405 based board , (OpenPilot revo ) to receive PWM signals from a joystick receiver . i have to xapture 5 PWM signals using only two timers , the timer 8 and the timer 12 . I've ...
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2answers
140 views

Convert positive square wave to positive-negative

I am looking for a way to convert a square wave coming from a microcontroller with voltage range from 0V to 5V, to a voltage range from -12V to +12V. The frequency of a square wave will vary from few ...
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3answers
59 views

How to up-convert PWM frequency without using a microcontroller?

I am trying to drive a motor H-bridge, but my control system can only support a 400 Hz PWM signal (black box, can't change it) which gives the motor an extremely loud 400 Hz whine as you would expect. ...
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1answer
54 views

Temperature stabilization with PWM , PID controller with delay system

I am doing a project to control the temperature with PWM. I use peltier, thermistor,mcu and h-bridge mosfet. I want to reach a temperature with an error less than 0.05 and stay at that temperature ...
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2answers
36 views

DC - DC Amplifier for Piezo Buzzer

I have a Raspberry Pi outputting a 3.3v DC square wave that I'd like to be able to amplify to just under 20v, the maximum the piezo can handle. Just to clarify, the piezo does not have an internal ...
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0answers
25 views

Pulse frequency for a pulse width modulation application

How can I determine the pulse frequency for a DC motor speed control or an LED brightness control. I have no data about the DC motor and led frequency dependence they both do not provide anything ...
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2answers
46 views

Basic h-bridge motor driver circuit for audio PWM waves with possible negative voltage

I need to control a DC motor with the PWM audio waves coming out of the audio jack of a device. The device will send a positive PWM to drive the motor forward and a negative PWM signal for driving it ...
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0answers
28 views

Can I connect TX- and RD- to their own ground? [closed]

Here now I have a problem, the singles I want to transmit is regular PWM, and I see the SFP got TD+/- and RD+/- I plan to connect the PWM output to TD+ and ground TD-, and got PWM singles at RX+ ...
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1answer
59 views

What is PWM Dead Band and when should I use it?

I'm having trouble understanding this concept, here is what the documentation in my microcontroller says about it: dead bands are defined as the number of PWM clock ticks from the rising or ...
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1answer
54 views

Mosfet life expectancy?

How to determine the life expectancy for the given mosfet? Mosfet : IRFP460 Mosfet Datasheet http://www.vishay.com/docs/91237/91237.pdf Actual Voltage,Current and other specification. Vds = 180VDc ...
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1answer
35 views

What is the name of the IC that runs a low-harmonic power supply?

I'm interested in building an AC/DC converter for low-harmonic applications. Single-phase AC input, followed by a rectifier and a PWM-controlled boost converter. I know there are ICs which are ...
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2answers
65 views

How to find duty ratio of a PWM using input capture?

I have a controller PIC18F and it supports input capture peripheral. I understand it can be used to find the frequency of the incoming signal. How can the duty ratio of PWM can be obtained from the ...
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1answer
46 views

Analog PWM generator from 0%

I have to prepare easy analog PWM regulator which can operate from 0% (0V). I know that one 555 can't do that... Do you know any circuit that can handle that?
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1answer
66 views

One PWM timer to two outputs?

first post here, so sorry for any bad styling. I'm working on a group project and using an Atmega328, without going into specifics, I need to drive two fans, two servos, and 1 CTC based function from ...
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1answer
43 views

Generate PWM signal based on 555 for Meanwell LDD driver

I am using a Meanwell Led Driver LDD-1000H. It has a single pin for PWM input for dimming. I have seen many sketches using the 555 to dim a LED but in these cases the LED was part of the circuit. How ...
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0answers
21 views

Controlling ESC with Arduino [migrated]

I want to control these motors: hexTronik DT750 Brushless Outrunner 750kv with this battery: Turnigy 2200mAh 3S 25C Lipo Pack and these ESCs: TURNIGY Plush 18amp Speed Controller. I am new to this ...
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1answer
105 views

Brushed DC motor control MOSFET selection

I want to control a brushed DC motor of the below specification: Motor: Permanent magnet DC brushed motor Voltage: 180V Current: 5 Amps RPM: 1500 The control method is PWM switching through a ...
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0answers
42 views

PWM to proportional bipolar control with push-pull amplifier. Need input and opinions

I'm putting together a circuit to control a (small wattage) TEC device in a bipolar manner. The idea is to have a micro controller put out a 3V3 PWM signal, level shift it between +- 3 V and filter it ...
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1answer
98 views

Adding more LEDs to a current regulating circuit

I am modifying a current regulating circuit that was designed to power three LED lights (see figure below). The circuit is designed to maintain current through the LEDs at 1A. The LEDs should be off ...
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1answer
68 views

Inductor calculation for DC to DC converter

How can I calculate the value and characteristics of inductor in a DC to DC converter?
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2answers
163 views

Microcontroller PWM to bipolar push-pull amplifier issues. (level shifting)

I'm trying to design a circuit that allows a micro controller (arduino) to control a voltage to a load. The load voltage needs to be bipolar in nature (+- 3 to 5 V) for use in controlling a TEC. My ...
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3answers
134 views

Sin signal from PWM

I wrote a program in order to use Pulse Width Modulation to simulate a sinusoidal signal. Added a low pass filter to get rid of the noise and the traces of it being a discrete signal. Added a half ...
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0answers
65 views

Generating and measuring PWM

Description of the main part of my project: A microcontroller should read 4x PWM channels, that come from a RX1. The frequency of the PWM signal is fixed (about 50Hz), the high time of the pulse is ...
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2answers
76 views

PWM control of air core motor

I am driving an air core motor using PWM control from a microprocessor. The position of the air core is dictated by the combined magnetic field created by applying 2 currents to 2 coils (sine coil ...
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1answer
139 views

How to replace bulb with LED in a PWM circuit (car)?

I want to replace a light bulb in a Peugeot 308 SW with a LED. The bulb works (lights) normally, but the LED blinks. I thought they are controlling the bulb in alternative current but my digital ...
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6answers
100 views

Converting PWM to bidirectional square wave?

Is it possible to make bi-directional ( symmetrical) square waveform from PWM signal? Im talking about 40 kHz frequency and 0.5v /-0.5v peak to peak signal.
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2answers
241 views

How to make a 12V DC variable voltage supply with more than 30A output?

I have a SMPS capable of outputting 33A at 12V and I would like to make it have a variable output with full current potential, or close to it. Now, Is it possible to do it with a PWM-controlled ...
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3answers
82 views

PWM controlled variable resistance

I found this circuit design for constructing a variable resistor. Its seems that the resistance can be controlled by the duty cycle of PWM on MOSFET. Would you explain what is the purpose of having ...
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0answers
67 views

PWM only works after touched with oscillicope probe

I am using two PWM outputs from a Netduino 2 to control two servos. One of the PWM pins works perfectly fine but the other doesn't work until I have touched it with an oscope probe. The probe doesn't ...
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2answers
117 views

Build variable resistor controlled by Arduino

I would like to build a variable resistor that can be controlled by Arduino. My plan is to vary resistance between the two values, i.e., 1 ohm to 10ohm, to continuously change the load for a small ...
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2answers
88 views

Opening MOSFET's gate with low voltage PWM

I have PWM of very low frequency and very low duty cycle. And max voltage comes out are 3.3. But thats not enough to open the MOSFET's gate(IRFP250N). Now I want to amplify the voltage. I do not have ...
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0answers
25 views

Emulating, tricking or faking a liquid cooling sensor

I have a specialty server board with an attached liquid cooling system, the liquid cooler has 3 pins attached to the board, pin 1 gnd, pin 2 12v+, pin3 sense. I'm assuiming this works like a cpu fan. ...
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0answers
50 views

MSP430 PWM Dead-Time

According to the internet, the MSP430 has no hardware implemented to maintain proper PWM dead-time as the PWM duty cycle is modified. Apparently (and also according to the internet) this feature can ...
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2answers
62 views

Generate PWM signal using GPIO

I want to generate a software PWM signal for 5 millisecond. using GPIO with 50 percent duty cycle and 100 KHz. ...
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1answer
61 views

How to calculate PWM duty cycles for Solenoid current control

How to calculate the PWM duty cycle for Solenoid current control I am trying to design a current control driver for Solenoid. I know the peak and the holding current range for solenoid. How would I ...
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2answers
95 views

Is it possible to use a ULN2003A Darlinghton array instead of multiple TIP120 transistors?

Looking at the datasheets, I'm not sure their specifics match; TIP127 and ULN2003A My intention is to do something like this, but with the ULN2003A, that I have already: The reason why is that I ...
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1answer
81 views

Eliminate PWM noise in PWM-driven bidirectional motor

I need to drive a DC motor with PWM, through a H-bridge. The controller can't generate PWM at ultrasonic frequencies with resolution I desire, and the low-end of the spectrum (~100Hz) may be too slow ...
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2answers
157 views

MOSFET gets hot when PWMing car high beams as DRL lights

The idea of this project is to have my car's high beams work as daytime running lights (DLR), with reduced light output. The DRL would turn on with the ignition on, and turn off, either when the ...
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vote
1answer
75 views

driving LEDs via a PI a attiny and TLC5940 (validation) and possible powering issues

at the moment I am planning my first real (big) electronics project. I want to build a LED lamp, that can be controlled by a RaspberryPi (for e.g. programming a binary clock or changing the brightness ...
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3answers
558 views

What are some problems with running a heating element in PWM mode?

I want to be able to control a heating element's (which runs on 230V mains) power level, and I'm thinking of running it using a solid state relay and PWM. However, I'm unsure of the implications of ...
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2answers
152 views

RGB LED strip, powered by an ATX PSU and controlled by PWM, makes my speakers buzz with Arduino connected by USB

I've not much idea about electronics, but I managed to do some little projects in the past. Now I'd like to place some RGB LEDs in my desktop PC windowed case. For that, I bought a 5050 SMD strip with ...
2
votes
1answer
34 views

PWM or switch port programmatically for Servo

Is there a huge difference between using a PWM and switching a port through a program (like using switch) for operating Servos? For smooth movement is PWM necessary or switching using a program will ...
3
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4answers
151 views

Why do most PWM LED displays and backlights operate at a relatively low frequency?

All around me are a bunch of electronics: digital clocks, my laptop, a refrigerator, a dimmable flashlight, and more. What they all have is perceptible flickering of their displays due to PWM, ...
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0answers
54 views

Varying the Frequency of PWM Inverter Modulation Function

I'm modelling a PWM inverter with a triangular carrier signal, and a sinusoidal modulation function. In order to get certain frequency of sine wave out of the inverter, I need to vary the frequency of ...
0
votes
1answer
52 views

Board or product to drive 15 PWM/analog outputs from USB/serial connection

Ok, Let me explain: I would like to drive 15 analogs (0-12V) signal from my computer (based on user interactions/other not-so-cool stuff). This hardware has to be controlled over USB or Serial port ...
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0answers
114 views

BLDC motor control PCB

I am trying to make a PCB to control a Sensorless Brushless motor. I just wanted to know if it looks right. The IC I am using is a TB6588FG it has a 2.5A peak output current. I want to use it with ...
0
votes
1answer
75 views

Controlling current in a PWM circuit

I have a PSOC Cypress board which generates a 5V PWM signal to drive a laser diode. The idea is to design a programmable pulse which I could control the on-time period and current in the pulse. The ...
0
votes
1answer
42 views

Help for PWM circuit for 12 volts DC up to 1.3 A

Is there a way to do a fairly simple PWM circuit that will handle 12 volts DC up to 1.3 Amps? The 555 timers appear to fall in the 600 mA to 900 mA max power dissipation range. Attached is the basic ...
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3answers
83 views

EMI due diligence

I had an idea to use the World Semi WS 2801IC used for addressable led strips with a power mosfet driver so that each address can be tied to a high current (~1-1.5A) load. The chip indicates the PWM ...