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

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Safe dead time limit on 19Khz PWM sine wave inverter

I'm buiding a 60Hz sine wave inverter based on 19Khz PWM generated by a PIC16F883 (lookup table) using a half bridge with 4 x IRF2807 - switching a pair of low-side/high-side. I'm using my own ...
0
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18 views

Class D Amplifier

For a piezomotor control I've used a class D amplifier TAS5162. PWM is provided directly to it with a microcontroller. I've made the same circuit as mentioned in the datasheet but instead of getting ...
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2answers
320 views

What do you call a 1:3 turn ratio transformer?

I need a small surface mount or slightly larger transformer with a 1:3 turn ratio that will triple my voltage from 3.3 to 9.9 volts. I have been literally searching the internet for such a thing and ...
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0answers
62 views

Audio POT with FET and PWM

I've been trying to build a simple audio pot to be controlled with PWM with an arduino, but I'm not sure why it doesn't work. I could do it with a LED (not directly which is simple, but with a FET), ...
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0answers
22 views

Achieving PWM wattage control w/o causing overcurrent fault?

I'm working on a project where I need to create a very compact PCB for a vaporizer. The target maximum power output is 15W. Currently I'm planning to use a TI TPS61088 boost regulator to boost a ...
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1answer
105 views

A question on PWM frequency of a DC motor

I'm planning to pwm-control four of the following motors by a single ArduinoUno: http://uk.rs-online.com/web/p/axial-fans/8179151/ For some reason the nearest pwm frequency I can set is 31kHz. The ...
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2answers
64 views

Arduino - Pulses get unstable when updating PWM duty-cycle

I'm trying to obtain stable pulse trains when adjusting the duty cycles wth an Arduino Uno board. In my actual project I need to use 4 adjustable PWM output pins at a fixed 25kHz frequency to control ...
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2answers
66 views

VHDL:CLOCK DIVIDER with duty cycle

I want to generate a 15MHz clock from a 60 MHz clock. The 60 MHz clock has a duty cycle of 50%. The output clock of 15 MHz must have 25% duty cycle. How the following code needs to be modified to vary ...
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1answer
100 views

mosfet bootstrap explained [closed]

I'm trying to get a hold on bootstraps for high side n-mosfets. as i currently understand it, it works somewhat like this: when pwm is high, mosfet is closed and capacitor is loaded to 12V. when PWM ...
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1answer
30 views

Effects of using a different PWM frequency than specified on device

I am wiring up a fan speed control circuit that creates a PWM frequency that is used by a PWM fan (the fan and its specs are pictured below). The fan claims that its PWM control is done through a ...
2
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3answers
257 views

Measuring current - shunt resistor or current transducer or something else

I have to measure current which is sine with 37Hz frequency 1350 mA(DC) + 190 mA(AC). The voltage in circuit is generated using PWM 27V, 600 Hz, PWM dithering adds alternating part of current. I want ...
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1answer
40 views

How to check currently which PWM device is active and in which pwmchip on BeagleBone Black?

I would like to control a servo motor using PWM. I have loaded the following .dtbo's in the slots in bone_capmgr directory as shown below: ...
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2answers
104 views

Strange Distortion from Second Order Active Low Pass Filter

I'm feeding a 250KHz PWM audio signal from an ATtiny85 into a second order active low pass filter: The output is then fed into a decoupling capacitor and then into an LM324 amplifier. The output ...
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0answers
22 views

TLC5940 at 8bit

Since I really don't need all them 12 bits of depth, I was wondering if the 5940 has an 8bit mode one can use? Reading the datasheet didn't quite help, and googling mostly yielded question by fellas ...
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3answers
78 views

Convert PWM to Analog using a DAC chip in order to emulate a Potentiometer for audio

I'm trying to control audio level/gain (from line or amplified signal) using an Arduino. I do not want to use SPI, for this project I can only use the PWM outputs, thus I do not want to use a digital ...
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2answers
158 views

What will increase output volume (dB) on a Piezo Transducer?

I need to achieve 110dB at 25khz from a Piezo Transducer. According to the datasheet, the resonant frequency of the Piezo is 25khz and at 10 vrms it will produce 110dB. I will be using an ...
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2answers
26 views

electronic speed control of 3 post compound DC motor

I've got a 12V DC winch motor with two field posts and an armature post (compound motor). Currently direction is controlled by four solenoids. Here's a diagram which boils this down two the two ...
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0answers
27 views

Troubleshooting HIP4081

I'm driving four N-channel MOSFETS (IRFLIZ44N) with a HIP4081, and the circuit looks like the following: The MOSFETS are driving a peltier module, and the input pins of the HIP4081 are being driven ...
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3answers
102 views

A mosfet switch for PWM signal

I was wondering if my circuit will work. The 5V signal is coming from a microcontroller, based on a condition. If its 1(5V) I want the PWM signal to be received by the motor. If its 0, the motor ...
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1answer
33 views

Beaglebone PRU PWM to Audio Signal

I was wondering if its possible to convert the high frequency PWM output from a Beaglebone Green's PRU into an analog audio signal. I was looking at building a low pass filter and I was wondering if ...
4
votes
3answers
183 views

How to increase mosfet switching speed, and decrease switching losses?

I hope this is not a too broad question, but what are the best practices to achieve fast switching on a MOSFET driven by a PWM signal? My current knowledge tells me I can do two things: 1 - To use ...
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1answer
131 views

Is this schematic good?

Here is schematic for DC motor control. Using this I can drive motor in both directions and also send short pulses to motor, to move it only a little bit in desired direction. Let me explain schematic ...
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1answer
42 views

Weird op-amp voltage increase when using AC-DC power supply

I'm trying to create a PWM signal to dim an LED. I came a across this circuit: When I tried it out on a breadboard powered by a 5v supply coming from my USB Digilent Analog Discovery, it worked great....
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2answers
99 views

PWM vs ESC for speed control for Arduino quadcopter

I'm from a computer programming background, but I'm interested in combining hardware with software, so I'm playing around with Arduino. Currently going through things on things needed to build a ...
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3answers
46 views

Techniques for driving inductive load, e.g DC motor, with PWM and constant current

I'm having trouble getting full torque out of a DC motor at anything other than full speed with a PWM driving circuit. Assuming the problem is inductance of the coils, what can be done besides ...
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2answers
60 views

What SMPS topology is this?

I came across this SMPS topology that I don't recognize. It looks sort of like a combination of a buck converter and a boost converter, but I can't quite figure it out. I haven't been able to find ...
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0answers
51 views

STM32F103C8T6 pwm generation

I wrote this code to generate a PWM but I did not get an output. What am I doing wrong? ...
7
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2answers
844 views

Audio using PWM, what is the principle behind it?

I have seen a schematic of a PIC board which uses filtered PWM to provide audio output signal to an audio jack. It shows PWM output filtered using 3 stages of passive RC filter followed by an LM386 ...
0
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1answer
26 views

Microstepping methods for stepper motors: PWM? Phase? Frequency?

I want to know what methods are used for microstepping stepper motors, and their pro's and cons For example, I presume, to hold the motor between two steps, PWM would be most efficient; simple ...
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1answer
48 views

Reversing PWM output

For an LED Driver chip I will be using, an inverse PWM signal must be used due to the way I will be wiring it, but could this be established by simply writing a value of (255-Value)-for 8bit PWM or ...
0
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2answers
63 views

Need to control (fade in/out, not just turn it on and off) a 240 V heat lamp. Is this even possible?

I'm a MechE and i'm way over my head in a project i'm working on. i need to be able to send either an analog or PWM signal to a heat lamp to allow it to fade in and out from dSPACE via a Unity project....
0
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2answers
50 views

Why is the capacitor voltage Vin*D?

I'm trying to understand turning a pwm signal to a analog signal. From what I saw online I found that using a lowpass filter, the capacitor voltage is Vin*DutyCycle. This was given as a fact and I ...
0
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1answer
57 views

Reducing the voltage of a PWM signal

I will be needing a 1.25V PWM input into an LED driver (AP8802) and will have to interface it with a 5v PWM output from a micro-controller (ATMEGA328). Would a simple potential divider do the job, or ...
2
votes
1answer
113 views

Designing a PWM controlled power supply for a 30W RGB LED

I am building a DMX controlled light using an Arduino, but I am not sure which power supply I should use to power the LEDs which run at 36v (10 in series, 3 rows) 30W. The main problem is whether or ...
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1answer
55 views

How to power a 150W with rechargable bateries?

I would like to build a gocart using a 150W 24V DC motor. To power it I would like to build a battery pack using 2Ah rechargeable batteries. The motor will run about 2 hours at 50% capacity (the ...
0
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0answers
25 views

Simulink how to convert Duty Cycle to reference voltage signals(Uref)

In Simulink I am creating a DC-DC buck converter using Average-model based VSC Universal. But one input of VSC is in Uref. For this case I need to convert Duty Cycle (D) into Uref for Input. Because ...
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1answer
102 views

I want to create a custom LED segment display. What do I need to study? [closed]

I want to create and then order a small run of a customized mass-produced LED segment displays for an art project. They will use PWM. It is not much more complex or detailed than a 7 or 16-segment ...
0
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1answer
42 views

Atmega32 PWM on all four PWM pins

I am trying to control LEDs brightness using PWM on the Atmega32. I have one LED connected to each of the 4 PWM pins (OC0, OC1A, OC1B, and OC2). Using the code below, all of the LEDs are functioning ...
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1answer
48 views

Strange behavior on transformer driver

I'm trying to make a circuit to drive a transformer from a PWM signal produced by an AVR MCU. Here's the schematic: The MCU output in fact has 2 complimentary PWMs feeding two transistor pairs. For ...
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2answers
76 views

Count PWM Pulses fed into Stepper Motor FET Driver

I am trying to (accurately) count the number of pulses fed to a stepper motor driver TI DRV8711. This driver "converts" one rising edge, depending on the settings, to a full step or microstep. The MCU ...
0
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0answers
53 views

4-Pin fan tach sensing gives weird results

I built a small setup to control a 4-Pin PC fan with my Arduino. Controlling the fan speed with PWN signalling works fine. But I can't get the tach readings right: The sense-cable from the fan is ...
4
votes
4answers
126 views

Methods for converting PWM to +/- 10v Signal

Suppose we have a PWM signal which controls the speed of a motor and a digital pin which specifies which direction a motor is travelling in, how can we convert these signals into 1 +/- 10V signal ...
0
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0answers
24 views

Measuring DC-Motor stator current

I am having some doubts about my measurements, and I would like to verify them if possible. I am using the circuit in the image, to measure the stator current of a DC-Motor, I just want to know if ...
0
votes
1answer
72 views

PWM signals averaged or not

I am using analogWrite(PWM) from Arduino UNO to control the gates of 30N06L N-channel mosfets. The values of PWM are programmed such that it controls the current through the loads for my control ...
0
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0answers
29 views

Controll Motor-DC using PWM in Proteus and MikroC for PIC

I am beginner (10 days) in Proteus and Mikroc, but i prefer to learn and this is the reason for my post. I build a project using PIC16F917 and Motor-DC with L298 driver. I command motor to start ...
0
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1answer
45 views

Remote control of DC motor

This is PWM controller I bought for speed control of DC motor: http://www.ebay.com/itm/6-30V-DC-Motor-speed-Controller-Reversible-PWM-Control-Forward-Reverse-Switch-/162002954574?hash=item25b820e94e:...
0
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2answers
75 views

From PWM Output to Large Motor Control

This question stems from my own curiosity, so forgive any vagueness. Imagine the following scenario: We have a MCU which outputs a PWM signal to control a motor's speed and direction. We ultimately ...
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1answer
54 views

Can I dim my LEDs even more?

I have a PIC16F1828. I am using PWM in order to control brightness of bunch of LEDs. My goal is to dim those LEDs to the maximum point. Currently they are not dim enough. System clock runs at 32Mhz....
0
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1answer
54 views

LED driver circuit with both analog and pwm control

I would like to design an LED driver circuit that allows for simultaneous analog and pwm control. That is, I would like to set the the LED current using an analog signal and then be able to switch ...
0
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2answers
67 views

Opto-coupled PWM

Following on from this question: I have the task of setting a voltage V_set using PWM. The challenge arises from the fact, that V_set is referenced to a different ground than the MCU. My currently ...