Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [duty-cycle]

Duty Cycle is the ratio between duration of a pulse and the entire period of a (repeating) square wave, expressed in %.

4
votes
1answer
619 views

STM32 PWM problem

Using a STM32F407 board. I want to generate a PWM signal. I have the following function: ...
0
votes
1answer
55 views

Adjusting duty cycle without affecting frequency of a VCO

I've looked around the internet for a simple voltage controlled oscillator that is able to produce various waveforms in phase with one another. I asked about it in this site and was directed to a dual ...
0
votes
1answer
42 views

Which Approach is Better to Drive Brushless DC Motor with PWM Duty Cycle

I'm doing a project that use brushless geared DC motor, the motor is connected to a moving platform. I will drive the motor with PWM, the motor then move the platform from -a degree to a degree ...
1
vote
1answer
44 views

High and Low times for 555 oscilator are inverted

I’m new to electrical engineering and this is my first time working with an oscillator. I'm trying to setup a 555 timer ic as an oscillator with a low time of 1s and a high time of 0.5s. I've been ...
0
votes
2answers
36 views

Run actuator at higher voltage and with lower dutycycles

I have an actuator which is rated at 12 VDC input voltage (0-15) with a maximum allowed duty cycle of 20%. The already existing voltage levels in my system are 5V and 22V, and since I am weight ...
0
votes
1answer
142 views

How to measure duty-cycle with Input Capture from STM32F103C8T6?

I'm trying to measure the duty-cycle of the 0-5V electrical PWM signal I have generated from the any source. How can I do this? Anyone can help me? IDE: Keil Microcontroller: STM32F103C8T6
0
votes
1answer
108 views

What is the physics behind width of the duty cycle in Arduino?

I was wondering if someone can tell me how Arduino changes the width of the duty cycle? How it produces an on-off pattern? I am looking for an explanation for modulation in this system.
0
votes
1answer
28 views

Determine MC34063AP Duty Cycle

A fuzzy area I want to clear up on the MC34063AP is Duty Cycle. In the MC34063AP datasheet, toff an ton are a result of 1 / f, which is obvious. toff is calculated by: 1 / f / ton / toff + 1 ton ...
0
votes
2answers
65 views

DC motor parameter identification using microcontroller

I've built a DC motor controller which measures the speed and current (not really sure yet about current values) of a permanent magnet DC motor. I plan to connect different PM DC motors. Is there a ...
1
vote
0answers
86 views

Optimal duty cycle in Forward converter?

So as far as I understand the Forward topology: The duty cycle set by the controller in CCM mode is constant assuming constant input voltage and constant output voltage. The duty cycle is independent ...
1
vote
4answers
826 views

Servo PWM: Why 20 ms period?

I'm working with ESC controllers which receive PWM signals that are very similar to those that control a standard Servo motor, i.e. a 50 Hz PWM signal (20 ms period) with duty cycle of 5-10% (1-2 ms ...
0
votes
1answer
97 views

Basic definition of duty cycle

Does the definition of duty cycle indicate only the percentage of time that the level is asserted? For example, if a 10 Hz square wave is de-asserted for 5 of those 10Hz cycles and asserted for 5 of ...
-2
votes
3answers
360 views

how to make a square wave 1kHz circuit [duplicate]

i want to make a 5V oscillator that has a frequency of 1khz. it will basically go to 5V (HIGH) and then 0 V (low) in a frequency of 1khz with 50% duty cycle.
2
votes
2answers
97 views

Is it possible to generate different PWM Signals for same duty cycles(e.g. 50%)?

Let us expect we have a duty cycle of 50%. Is it possible to reach that duty cycle with different PWM Signals (waveform)? With different I mean variants in the number and lengths of the "active time". ...
0
votes
2answers
182 views

How to regulate PWM to control a boost converter

I am creating a simple boost converter following the classic circuit diagram just for learning purpose. The switch is a power transistor controlled by PWM output of an Arduino (with additional ...
0
votes
1answer
185 views

Defining contrast ratio and dimming ratio in a LED driver

I read in this article which analyze the contrast ratio achievable with switched mode LED driver system, that is defined as \$ \frac{1}{t_{on}} : 1 \$. Intuitively I can get that the minimum time ...
0
votes
0answers
40 views

Analysis of the full bridge bidirectional converter's buck mode operation?

This is the circuit I was trying to learn. Here is the equivalent of the buck mode operation: And following is the waveform in the buck mode of operation: My intention is to derive the output ...
1
vote
1answer
80 views

How can I add variable duty cycle PWM to a CircuitLab simulation within a question?

This is my first attempt to simulate a circuit in the time domain with CircuitLab. In order to ask a proper question about something similar driven with PWM, I'd like to add an adjustable duty cycle ...
0
votes
1answer
108 views

Control the duty cycle of my square oscillator

I Would like to know how i can control the duty cycle of my circuit. simulate this circuit – Schematic created using CircuitLab What is the best way to control the duty cycle ( from 1 to 99%) ...
4
votes
4answers
2k views

analog PWM signal

I am trying to get a PWM signal with adjustable duty cycle using only analog components, hence using a timer is not possible. Now I got one way of using it, using the triangle waveform and putting it ...
1
vote
1answer
586 views

Pulse generator with single op amp and diode

I want to design pulse generator with specific period and duty cycle. I found a pulse generator with single op amp and diode. I couldn't find information about how to calculate period and duty cycle. ...
0
votes
1answer
2k views

Driving servo motor with PWM signal

I want to drive servo motor with PWM signal.Servo motor rotation angle changes with the ratio of the duty cycle.Generally , servo motor rotation angle according to PWM can be seen in figure below. ...
0
votes
0answers
66 views

Fire alaram sound using PIC16F886

I am coding on a PIC16F886 IC. I am trying to generate a fire alarm sirene with a PWM signal. I have some questions as stated below. I copied code the from Example code My speaker circuit look like ...
0
votes
2answers
280 views

The logic schematic which can change the duty cycle of input

Is there a logic schematic can change the duty cycle of input ? I mean if input is a square wave with duty cycle is equal to 50%,and the output is also a square wave but its duty cycle become lower or ...
0
votes
2answers
2k views

independent control of frequency and duty cycle in 555 timer (formulas)

I want to control frequency and duty cycle of output pulse of 555 timer. I searched and find this schematic in a post in SOV but I don't know how calculate frequency and duty cycle in the circuit. ...
0
votes
0answers
352 views

sampling frequency for less duty cycle message signal?

I have a question regarding the sampling frequency ? Normally we will take 50% duty cycle square/ sine wave to explain about sampling frequecny/ nyquist theorem.. My doubt is what is he sampling ...
0
votes
2answers
954 views

how do I control duty cycle of a MOSFET using PI controller

I have designed a buck boost converter, how can I use a PI controller which will automatically change the duty cycle of the mosfet as per my desired output voltage or current? I have been fidgeting ...
0
votes
1answer
110 views

'Subcircuit is undefined' when designing PWM with TL493 in PSPICE

I am trying to design a PWM for my converter using TL493 in Pspice and i am getting an error. ERROR(ORPSIM-15108): Subcircuit model591_tl493 used by X_U1 is undefined i am a beginner to both ...
2
votes
2answers
2k views

Do 100% duty cycle buck converters have no voltage drop?

I am currently designing a circuit which should be able to take 12-28V DC power in and output 12V DC @ 1.5A. The question is: is this possible with a 100% duty cycle buck converter (like TPS54302)? ...
1
vote
1answer
63 views

Duty Cycle Demodulation Distortion Correction

I'm trying to come up with a system which will reliably convert an arbitrary input to a PWM signal, and then back again. The comparison signal is a 50kHz sine wave, and the result is fed through a ...
1
vote
5answers
3k views

Is there a way to sweep duty cycle over time in LTspice

I can sweep the frequency in time by using modulate, but I couldn't find any example on creating a varying duty cycle or a duty cycle is swept from zero to 100% at a given frequency f in a time ...
0
votes
1answer
199 views

Average voltage (pwm regulated) out of motor voltage range?

My DC brushed motor is rated 4.5V-15V. My application requires the motor to spin with different speeds so I am using PWM to regulated the it. I will be supplying the motor with a 12V battery and using ...
1
vote
4answers
917 views

100% Duty Cycle PWM

I recently had to build a filter to go from PWM to 0-5Vcc, and it got me thinking... At 100% duty cycle, the PWM used was 100% 5V output, DC voltage... If i used this PWM to, for example, switch a ...
0
votes
0answers
4k views

DC motor speed vs PWM duty cycle

I understand there have been quite a few posts asking about the DC motor speed vs PWM duty cycle issues. However, I found those questions different from what I want to ask, so I have to ask this topic ...
-1
votes
1answer
1k views

555 - Adjusting frequency without affecting duty cycle

This seems to be some easy thing someone figured out already, but here I am after an hour of searching - and fearfully asking the question. My aim is to build a relatively simple 555 circuit using as ...
-1
votes
1answer
73 views

How to keep a 110V appliance ON for 1 minute every 5 minutes, without arduino? [closed]

I need to turn ON an appliance (110V, 0.5A) for 1 minute every 5 minutes. The immediate solution that comes to mind is arduino/raspberry-pi and with a relay. What kind of circuits would help me ...
0
votes
1answer
54 views

Thyristor in a choppercircuit

I've the following kown values: Switching on loss is \$\text{E}_\text{on}\space\text{J}\$ in \$t_\text{on}=\tau_\text{on}\space\text{s}\$ Switching off loss is \$\text{E}_\text{off}\space\text{J}\$ ...
0
votes
1answer
1k views

IC Timer 555 Astable Multivibrator 50% Duty cycle

I'm given this configuration to solve for a IC-Timer 555 in astable mode to get a 50% duty cycle however I'm having some difficulties in the calculations. The circuit is modified a bit as shown. ...
1
vote
0answers
349 views

What difference a change in hertz vs duty cycle make to the pitch of a sound?

For example, 100 hertz sounds very low, but acquiring that from an online source that doesn't tell me the duty cycle doesn't answer my inquiry into whether a change in the duty cycle will affect the ...
0
votes
1answer
448 views

Pulse width modulation sensor circuit

This is the circuit of a PWM temperature sensor, I will give you some details about the circuit: The Electronic control Module which supply power (+8V) at terminal (A) The Electronic control Module ...
0
votes
1answer
75 views

mechanical oscilator concept to drive electric motor [closed]

I have been thinking about a project for some time now and am wondering how well it may work. I would like to make a sleve which could be run by a small electric motor ie from an old cd player or rc ...
1
vote
2answers
720 views

What is the influence of an asymetric load capacitance on a crystal duty cycle

I have a crystal oscillating at 25MHz (datasheet). The recommanded load capacitance is 18pF according to the datasheet. The crystal is connected to a component where the capacitance on the pin are ...
1
vote
2answers
173 views

Is a switching power supply likely to fatigue or burn out early if turned on or off quickly?

I'm working on a design for growing biomass where I need high power LEDs to switch on and off somewhere in the neighborhood of 1-30 times per second, so that they provide light to grow but don't ...
0
votes
1answer
120 views

Can't understand a variable in the formula used to determine CDTY to set duty cycle of PWM on cortex M3 (SAM3X8E)

I want to generate complementary PWM on an Arduino due. For that purpose I am programming the cortex M3 using the PWMC library. In order to set the duty cycle I have to set a value in CDTY channel ...
2
votes
2answers
145 views

High Current Pulse Opamp 2.5% Duty Cycle

I am driving an IR LED (LED914 and LED907) in series at 4.5 A for 2.5% duty cycle, In the 28 V I connect a DC supply and set the current to 150 mA, the idea is to continuously charge the capacitor C17....
0
votes
1answer
947 views

PSpice PWM duty clycle generation from PID controller

I am trying to implement an ideal PWM controller in for an analog circuit I have in ORcad PSpice. Ideally I would use the SLPS tool for simulink, but unfortunatelly we do not have the licence for it ...
0
votes
2answers
2k 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 ...
3
votes
1answer
143 views

Relaxation oscillator with two time constants

I have the following circuit and I have to find the duty cycle of the output signal and its frequency: I figured out that if \$v_{cond} > 0\$, then D4 will be forward biased and D3 reverse biased, ...
0
votes
1answer
1k views

VHDL - 10% Duty Cycle

I need to generate 500Hz from 50MHz clock frequency. I already got it. My problem here is how should the code to be adjusted if I want to change the duty cycle to 10%? Thank you. ...
0
votes
2answers
728 views

How to balance between frequency and duty cycle in this circuit?

I have this astable circuit that generate square waves with independent control of frequency and duty cycle: For this circuit: $$t_H=0.759\,C\,(R_f+R_y)$$ $$t_L=0.759\,C\,R_x$$ $$period = 0.759\,C\,(...