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Questions tagged [pwm]

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

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Can I use a 555 PWM signal to control

I want to use a 555 PWM signal to control a motor. I also want represented the speed of the motor with an LED graph using a LM3914 led driver. Can I use a digital signal to control the LM3914 ...
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50 views

pwm RC filter question

I'm new here but been playing with electronics for a while now. I have this project where I'd need to read pwm controlled signal from mosfet. This is how stock application controls pwm valve: I want ...
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20 views

Does my PWM led circuit controlled with NodeMCU and Mosfet work properly. What should I do to improve it? How to calculate for each components?

If I understand it right, when there's is signal from ESP, the PNP and NPN be ON, and Vgs=0. If they're OFF Vgs=+12V and the LED will shine. R=1K is to limit the Ib of NPN, and R=10K is the resistor ...
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9 views

16-Channel 12-bit PWM/Servo Shield check if it is powered by adapter [migrated]

I'm using Adafruit 16-Channel 12-bit PWM/Servo Shield with Arduino Uno controller In setup() I have a number of default positions ...
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15 views

Producing Bi-Phasic Constant Current Pulse using L293 IC

I am trying to convert a current source output into the bi-phasic pulses. I thought maybe using L293 IC might help to change polarity of the currents. Here is the picture of design: as can be seen ...
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1answer
132 views

Is there any advantage to using multiple tracks in this PCB design?

I'm fairly new to PCB designing, but I'm loving experimenting with it. Currently, I'm trying to develop a simple PWM circuit using MOSFETs to control an RGBW strip, using an Arduino with an integrated ...
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2answers
39 views

Understanding Mosfet Circuit with PWM

I am wanting to control a voltage range of 0-10v across a 10k load with PWM from a micro. Now I was told to use this circuit with an n channel mosfet: This is what I understand so far: R1 is to ...
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3answers
852 views

Resistor Selection to retain same brightness in LED PWM circuit

I am making a simple LED PWM brightness control circuit. I am using a relatively high power White CREE LED, N-channel Enhancement MOSFET BSS316N and Resistor R. The circuit is as shown below. I am ...
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1answer
52 views

How to choose an inductor for a LCL filter?

I am trying to make a voltage generator. I used an inverter and it is controlled by a PWM signal. I used a LCL filter to filter the output signal since it is rich in harmonics but in the choice ...
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1answer
24 views

Voltage or Current Control with a Microcontroller for Pressure Regulator

I am wanting to control the flow rate of a pressure regulator (https://www.festo.com/net/SupportPortal/Files/505126/VEAB_2018-05a_8080669g1.pdf). My idea is to control this with a PWM signal 0-5v. ...
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1answer
44 views

Inverting output of gate driver for MOSFET

I am using this circuit to control the speed of a small motor (12VDC, 0.3A). The arduino PWM output saturates a 2N2222 NPN transistor which saturates the mosfet gate. My issue: when PWM is high (5V), ...
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64 views

What LED PWM controller has marking AT508CS?

I have an LED worklight with low- and strobe-functions. One click: On - full Power Two clicks: half Power Three clicks: strobe Four clicks: Off The controller is circled: No markings on the top ...
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38 views

Buck Converter MOSFET Output Voltage distorted (PWM)

The input to my buck converter MOSFET switch is a PWM signal with a certain duty cycle. However, upon observing the voltage waveform of the MOSFET, the voltage is a bit distorted. The input to ...
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4answers
1k views

PWM 1Hz on solid state relay

I'm about to build a pid heating controller with a 1kW heater and a solid state relay. The ESP8266 can go down to 1Hz pwm frequency. So hopefully I can vary the number of active cycles per second, ...
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1answer
40 views

PWM fan with PWM wire disconnected [closed]

What will happen when the supply and ground are connected for a CPU fan with PWM but the PWM wire is not connected? Will the fan run at its full speed?
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0answers
52 views

How to disable timer on MSP430?

I am new to the TI MSP430G2553. I would like to send a PWM signal like in this picture: (Image source: Adafruit - Understanding Infrared Signals) However I can't do that, because I don't know how to ...
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1answer
22 views

MP3301 LED Driver RC Filter Calculation for PWM

I am looking at the datasheet for the MPS MP3301 Step-up LED Driver. I have two questions about the "PWM Dimming" section on page 8. The datasheet says for PWM frequencies > 1kHz, use an RC filter ...
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1answer
33 views

Using arduino and transistor for motor control

I am currently a computer engineering student trying to build a simple circuit to vary voltage by using a transistor and a arudino uno. The motor draws between 12v and 28v with a current of about ...
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0answers
33 views

Generate ePWM with F28379D

I'm trying to generate an EPWM signal with my Launchpad from Texas Instruments. I want it to be 50 Hz with a pulse of ~1 milliseconds in order to turn a servomotor (SG90) to -90°. This is the code I ...
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1answer
69 views

Heating rods control using PWM

I'm not an electrical expert and lately, I ran into a problem using PWM for steady control of a heating rod. Let's assume there is a set value (Temp in C) for the heating rod. I'm currently using a ...
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2answers
94 views

Control 12V DC via MOSFET and normal transistor

I made this schema and I want to ask, how transistor control MOSFET. What that s8050 transistor do with the IRFZ44N MOSFET. Please, help.
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1answer
79 views

Is it possible to drive a low voltage (7V) brushed DC motor with a low duty cycle, 220V DC source?

I am trying to drive brushed DC motor rated at 7 volts in only one direction. The motor can sink high currents under load (I expect up to 20A). My genius plan is to run it from rectified mains ...
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1answer
38 views

Motor Speed Output Signal [closed]

I need an advice. I just got a DC motor and its controller board. On the controller board it has 6 pin/wire: +12V, GND, PWM, ENABLE, DIRECTION, SPEED OUT. What I want to know is how do I interpret ...
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3answers
62 views

How does PWM work in the Arduino?

The problem that I have is that I can't understand the working of PWM in Arduino, even though I totally understand what PWM is. Like the Arduino has a 980hz refresh rate (~1ms clock speed) on two of ...
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1answer
77 views

I want to create a stable 0-10 V DC output from a 3.3V PWM signal (arduino/esp8266)

I want to control an EC motor, but I have some difficulties with the motor's control input. According to my measurements it has a ~50kOhm input impedance, and probably also has an (unknown) RC low-...
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3answers
116 views

Trying to recover audio from PWM

I am trying to make a Raspberry pi Bluetooth receiver. I finally got the raspberry pi to output audio via bluetooth, however the output seems like it is a modulated PWM. The width of the PWM seems to ...
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2answers
55 views

Does operating a DC motor at low PWM freq (500 Hz and below) deteriorate the motor performance?

What impact does a PWM signal of 500Hz and 20KHz have on a DC motor, especially in terms of performance, life-span of the motor, etc? So far I have seen posts that only talk about the buzzing sound ...
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1answer
48 views

Will it harm a PWM fan controller to be backfed full fan voltage?

I want to install a PWM controller to a small 12 volt furnace fan in a camper. I want the fan to run slowly after furnace shutdown, to quietly stir the air for more even heating. My thought is to ...
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2answers
38 views

Strange behavior in a non-inverting op amp

I've designed a simple non-inverting amplifier to interface a 3.3V MCU and a 5V signal to a motor controller. When I first tested with the MCU and the desired values to the low-pass filter, I noted ...
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1answer
81 views

How can I use PWM to power a 1.5v dc motor with an 5v board Arduino UNO?

I tried to calculate the value for analogwrite which is 77 but that doesn't work. I also tried a bunch of other value but none of them spin the motor. Is this possible and am I missing something? the ...
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1answer
85 views

LED-drivers FAN5331 and FAN5333

I have a question about the following LED drivers: FAN5331, datasheet http://www.mouser.com/ds/2/149/FAN5331-92198.pdf FAN5333, datasheet https://www.onsemi.com/pub/Collateral/FAN5333B-D.pdf They ...
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37 views

Regenerative energy Dissipator for BLDC motor

I want to design a circuit to dissipate the reverse energy from BLDC motor, can I use PWM control technique in voltage sense circuit in order to switch on the power circuit? In detail : In my ...
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3answers
195 views

How to control BTS7960 43A motor driver directions?

The board has two PWM inputs, see: Do I have to use four pins to control two motors? Thanks
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0answers
25 views

How to interpret power MOSFET datasheet for PWM usage?

To explain shortly what this is about, I have two 3D printers with similar motherboards and I want to edit the firmware to achieve the best safety regarding the specifications of the MOSFETs used. ...
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3answers
62 views

Buck converter, duty cycle has inverse relationship with Vout?

I've been trying to design a DC-DC step down (buck) converter for a school project, and have been getting unexpected results. I'm using a PWM signal from an arduino to step down the voltage, and have ...
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1answer
50 views

Variable PMW generator using Verilog [closed]

I've made a code in Verilog for a variable duty-cycle digitally controlled PWM generator. I will be using it in a system I am designing for controlling a buck-boost converter that will regulate the ...
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0answers
120 views

STM32 Input capture PWM frequency measurement problem using HAL

I'm trying to measure time passed between two external interrupts generated by rising edges of a PWM signal (generated using a IC 555 timer). Point is to determine the frequency of the signal. I'm ...
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1answer
53 views

PWM Controller for known f(t)

Suppose I have some signal input which I know. The signal is 85 seconds long and its not something I can describe with equation but It looks as follows: Now, I have made a simple PWN controller that ...
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1answer
27 views

driving a medium power darlington transistor with the output of a 555 timer

Question: What is the limitation on the output of the 555 timer with respect to the requirements of the input of the BDW42G? Can the 555 provide enough current at 5 volts to trigger (sufficiently) ...
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2answers
536 views

if(){} else{} if(){} VS if(){} else if(){} in PWM control [closed]

I'm using timer0 and a gpio pin to generate a 300Hz PWM signal on an ATmega2560. The details if you care: F_CPU=16M, timer clock prescaler /256, count_max=208 The frequency changes depending on if I ...
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0answers
31 views

Insufficient torque from motor connected to H-bridge

I'm currently attempting to convert my son's broken 1:14 scale R/C Bugatti Veyron (similar to this) into an app-controlled car using an Onion Omega with a servo/PWM expansion. However, I am having ...
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56 views

Demodulation of a 38 kHz IR PWM signal

I want to learn how to demodulate a 38 kHz IR PWM signal.(Such as that transmitted by a TV Remote Control) I know it can be demodulated easily using a TSOP1738 IR receiver. I realize that the ...
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0answers
33 views

TLC5940 SOUT/SIN signal broken after 4th daisy-chained IC

I have a PCB with 5 TLC5940's daisy-chained. The first 4 work fine, but the fifth doesn't work. The LEDs connected to that one just go on at full brightness and that's it. When I measure the SOUT to ...
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2answers
2k views

I found an audio circuit and I built it just fine, but I find it a bit too quiet. How do I amplify the output so that it is a bit louder?

I want to try something audio related and found the following circuit from technoblogy I built it and loaded a sound clip. Everything works fine, but I found it a bit too quiet and I want to amplify ...
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58 views

PWM Not Driving IRL520N MOSFET

I am trying to switch a IRL520N logic-level MOSFET using a 0-5V PWM signal from my microcontroller (PyCom FiPy). I tested just the MOSFET with a 10 Ohm series gate resistor and my load is a 9-15V ...
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0answers
37 views

LTSpice PWM Signal Showing Capacitor isn't Fully Discharged

I'd like to create a pwm signal input to mimic a real life situation of a pwm input that shows the capacitors aren't fully discharged. Please see the image below. I am currently able to create the pwm ...
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2answers
96 views

Why does the MIT Racecar not use the build in ESC?

MIT has build an autonomous RC race car. They put everything on GitHub. I have a similar project and therefor build one of those for my self (Almost the same but without TX1 and Sensors). I am ...
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1answer
71 views

Class D Amp headphones grounding circuit

I am having a problem with some of the class d amps I've played with (PAM8302A), and it seems like this article here describes my problem: https://www.edn.com/design/analog/4313726/Add-headphones-to-...
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2answers
76 views

Light sensors sensitive enough to detect for PWM from CF and LEDs?

I have an extreme sensitivity to PWM light sources such as computer screens and light bulbs. This can make it very challenging to make a purchase as I end up having to do lots of guesswork with ...
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2answers
131 views

Transistor not cutting off at 0V

EDIT: I edited the question as it was my misunderstanding to think that the transistor was not getting into saturation. I'm driving an LED with a microcontroller through a transistor with a PWM ...