Pwm Definition and 74 Threads

Are any of the low-flicker monitors completely flicker free, not just low enough flicker to meet some low-flicker certification. Ideally I’m looking for something completely flicker-free like the LG EVO OLED TVs but smaller. I do not know all the terminology but some things I’ve been told to...

How do i simulate the PWM signal with duty from 0% to 100% in Ltspice. I can generate a pwm signal with single duty.

I am experimenting with finding the resonant frequency of water in an attempt to disassociate the H2O bond without high voltage/current and using just tap water - no electrolytes, etc. I know how it works in classic electrolysis but that's not what I am attempting. Assume that there is a...

Hello how are you :D I have some problems with my code, which is to control the speed of a DC motor by pwm with the pic16f84A. I already have the combinations and the diagram of the signals, but I still need to implement the part in bold. How would the delays be implemented so that they have...

After we got the solar array working, we made all lamps, laptop chargers, most kitchen appliances... run on 48vDC (so that we can have the inverter switched off unless we're running any 220v appliances). Then everyone in the house got a headache. We traced this down to being indoors at daytime...

This is a PWM signal generating circuit based on LM393. When I was running this LM393 circuit, I found that this circuit only consumes about 10 milliwatts of power at a voltage of 5V. Not only that, this circuit can work normally at 3.3V, 12V and 18V. But later I found that this circuit...

Need some sources on why PWM is widely used in inverters for DC - AC conversion applications, and their mathematical basis? Basically, I was wondering why inverters had to use PWM, instead of just getting a square wave of let's say a 50Hz frequency and just filtering out the odd order harmonics...

Hello, Looking for advice/thoughts on a PWM signal going across multiple PCBs. The signal would be relatively slow (1kHz) but I've really only ever dealt with PWM on a single board or cable. The premise of this effort would be to have a PWM control signal and be able to daisy chain multiple...

Hello guys, I am looking to control the flowrate of water through a Solenoid Valve in a continuous closed-loop process. I inquired about Proportional Flow Solenoid Valves and these are a little too expensive and only a handful of manufacturers are supplying those. But I looked online for some...

Hello, I wanted to ask, if anyone knows of a realistic circuit, which could be capable of producing a PWM of 1 pico second on and 350 ps off. Thanks to everyone taking the time to answer in advance.

Ok, so i have a picaxe microcontroller putting out a pwm signal to the gate of an irlb3034 "logic level" n-channel mosfet. The mosfet is for grounding on and off about 8v of 20 to 40 amps. When i take my circuit and jump 8v directly to the gate of my mosfet everything works perfectly...

Hi, Thinking of a circuit to control the AC power to a heating element. I wanted something fairly linear, and analog. I don't have anything against using a programmable controller, I just wanted to think of an analogue solution, seeing as I don't need to learn how to write a program. The...

Hello everyone, I have to control a solenoïd valve proportionally using a 166Hz PWM signal. The resistance of the coil is 2,5-4 ohm. If i'd be using a pure DC signal I'd have around 8 amps of power. However this is an oscillating signal. Since a coil resists changes in current, the effective...

This thought occurred to me when reading about class D amplifiers, which essentially "emulates" amplification by very quickly switching on and off. Could one use the same principle to eliminate for example heat losses during impedance matching? IIRC, in the perfect condition of matched...

I need to build a light dimmer using the PWM on the microcontroller to dim an incandescent 60W bulb. What would be the simplest way to do it ?, any suggestions ?, would a optocoupler and triac suffice ?

What are some effective ways to convert a Pulse Width Modulation from a Microcontroller to a DC Voltage as a function of Pulse Width? 1. Use a low pass filter to remove the unwanted harmonics and leave only the 0th term of the Fourier Series. What produces a better DC Voltage an Active or a...

I need an algorithm for generating a pwm (pulse width modulation) sine, but with an important constraint: it is not allowed to use a lookup table. The pwm encoded sine pulse sequence must come directly from the algorithm itself. All attempts to find it were in vain. Can you help me? Thank you in...

So, this is what I know so far, please correct me if I'm wrong. The amplitude of the output of a PWM inverter depends on how long the sinusoidal modulating signal is greater than the carrier. If you subtract the output (scaled down) from a reference signal in order to get some error and use...

I am doing a project where I need to control brightness of a led light. according to presence. the brightness can be controlled using pwm but I cannot find a way to do that for high voltage input signals.

Hi,So let's start with this, I don't have a lot of electronics circuits background and not really an idea on how to build an electronic circuit. Ok, now the problem, at my job I am in need of controlling a 24VDC 0,570 Amp pump with a pot, preferably one with a "preset" in it so that the values...

I am an electrical engineering student. I have been on summer break for a few weeks now and I had time to work on my project. This is not a school project but something I had wanted to complete for a while. I haven’t decided what I am going to do with it yet. I just built it for the fun of it...

Hi all, I am an electrical engineer and feel I should know this (embarrassing!), but I for the life of me still can't quite get this concept. I understand conceptually the idea behind a pull up or a pull down, in that we want the IC to read a high state, by defaultm in the case of a pull up...

Hi Everyone, here is Hubert again. Here attached is my design and the problems I am facing. Can anyone be of help? Thanks in advance. Best regards Urbain

I need to design a pwm circuit, i using the circuit from internet that i attached it.. freq is 20khz which is my requirement and 15v to power up the tl494.. there is no response when i connect potentiometer to it... waveform is attach can anyone give me advice?

Hi, I'm a starter here! I am trying to build a buck converter without the use of any IC. I want to drive a single LED. Here are some calculated data: Vin =5V, Vout =3.225V, Duty circle = 0.651, L=6.8micro Henri, Switching frequency = 1.4Mhz, Desired current is 1A, I also assume ripple current...

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. What I understand so far: The motor will only turn when the diode is reverse biased. When it...

I'm building a machine using a 3-12VDC gear motor, 1.5A draw no load, stall at 25A. Would a PWM rated at 6-90V 15A 1000W be an appropriate controller? These two items: https://www.amazon.com/gp/product/B00HTZSK5Q/?tag=pfamazon01-20 https://www.amazon.com/gp/product/B005IR1NBA/?tag=pfamazon01-20

I've carried out some testing on a PWM controller using a 555 timer IC (see attached for circuit diagram) and I am having a little trouble understanding the results. When the POT resistance is increased the duty cycle decreases. As I understand it, when the resistance is increased the voltage...

Hi, could someone confirm whether I am right in thinking that for a PWM inverter, the input sine voltage is converted to DC using a bridge rectifier? Does this DC voltage then have a value which is the same as the PEAK value of the sine input? Is the DC voltage then 'chopped' using IGBT's to...

Hi, I understand that the PWM inverter drive system first uses a diode bridge rectifier in order to convert the AC incoming into DC before using an inverter to convert this DC into PWM for use on the induction motor. Could someone please explain in simple terms how the PWM inverter section...

Hey guys, So I'm working on a project currently being built off of a cheap commercial Quad-copter (Syma X1) as it's base platform. Just as a little background I am trying to make it so that it is not controlled by a remote (that is pushing knobs and levers up and down to control it) but by EMG...

Hi, I need help with my electro magnet pulse with modulation PWM. I have a Velleman® IR Light Barrier Kit from Radio Shack and this kit is ment to turn on and off a 9V buzzer. But instead of soldering in the buzzer I tried to hook it up to a MOSFET transistor NTE2984 so that I could use it with...

I'm making a circuit to control the temperature of a peltier element, and I'm trying to figure out the cheapest way that will actually work over the long term, and not burn out my components fast. At first I wanted to just use standard power regulation to control the power to the element and...

I'm trying to control the speed of a computer fan using the radio input from an RC transmitter/ reciever. The PWM output of the reciever is 1ms to 2ms high and 20ms low, so 10%-20% duty cycle. The computer fan requires a 30% to 100% duty cycle, at 25khz (about a 40uS pulse) I was thinking of...

Hello All: This may be a repeat post - I looked at my history and did not see it. I am looking for a product ( finished/qualified) that takes a standard Analog signal ( 0-10V and/or 4-20mA) and converts to a PWM signal with fixed but settable; Frequency of ~ 100 to 5000hZ - possibly with a...

I want to controll ac motor using pwm.sir told me for that you required volage controller and phase controller.if voltage is controlled by pwm so why i want to use this phase and voltage controller?

Hello. I'm trying to control the speed of a fan (12V cpu cooler) with PWM (555 + MOSFET). Should be quite straightforward, but i noticed that the speed of the fan does not seem to always change in the same way the duty cycle does. With an optical RPM meter I'm seeing that the lowest RPM...

Peltier Project: 50% PWM --> alternate circuit switching for increased performance? Hi all, I have a project where I am making a drink cooler device using four peltier devices which can draw up to 30amps or 24 volts each. we are considering battery power (pretty ridiculous but anyway..) and...

Hi, I am debugging a C code of a heating machine. I am so confused about real time current and programming control over all the parameters of the machine. The code was written by some one though, i understand it well until now. Problem is that the previous code works according to...

Excuse my lack of knowledge on PWM and fans, but can a fan configured with 4 wires (power, ground, tach. signal, and PWM input) be run off of a DC power supply without using the PWM to control its speed? As in, not using the PWM lead and just hooking up power/ground and controlling fan speed...

Hi, i need an oscilloscope but i don't have money to buy one, so i was thinking about some way to use the PC to emulate an osciloscope. I saw on internet people using the sound board, but they say that's a lot of interference... So i found a PC Oscilloscope and i wanted to know if it works. I...

Hey everyone. I am a total noob to electronics, so I would really appreciate your help on my first engineering project! I am building an RC Excavator and need help with the circuits for the linear actuators I plan to build. I have 3 DC motors on the way with a voltage range from 6-12V. I have...

As part of a lab report I have to determine the speed of a motor from the PWM waveform. The motor in question is a lego motor, of type at disassembled at http://www.philohome.com/motors/motor.htm. It has three coils on the rotor and a 4 pole permanent magnet stator. This is the waveform I...

hello friends, how can i generate a PWM control 2 kHz with PIC16F84

I need to design an electric circuit which require PWM to let the battery and supercapacitor take turn to supply current to the loads. stage1: battery charge up supercap and supply current to the load stage2: supercap voltage increase to a certain level, battery current is cut, supercap...

Hi! I have been getting really confused about this one thing. Can someone please clear my confusion ? Is there a difference between Pulse Wave and Pulse Width Modulation? If yes, what is it ? If no, can one be used in place of the other ? :smile: Thanx !

Hello everyone. My first post so bear with me. I'm planning on buliding an arcgenerator (and possibly an arc speaker later on if this works) with my arduino and a coil. I'm relatively to electrical engineering, so there are a few things I need some help with. If I've understood things...

Hi everyone, I am really trying to get the concept of Servo Motors and am sort of stuck on something, particularly how the motor gets its Pulse Width Modulation. I understand the 0 to 5V with a period of about 20ms and different pulse widths generate different angular positions. What I am...

Greetings! This is my first thread. I am creating a 200V bulb dimmer using PWM and IGBT. Currently, this is how I connect the components: The output of the PWM goes into the gate of IGBT. The bulb connects in series with the 220V supply and the collector of IGBT. The emitter of IGBT is...

I am using 4 MOSFETs in an H-bridge. The H-bridge is controlled with two MOSFET drivers (specially IR2113). I aim to drive the H-bridge via PWM which is carrying a 50Hz sine wave. Note that, the load is not a motor. Instead, the H-bridge is being used as a inverter. My question is, does the...