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136 Threads found on edaboard.com: Pwm Generator
I suggest you record and FFT your power supply noise, then replace mic with a resistor then use a sine signal from a sig generator and compare results. 8 bit pwm will be quite poor for sound quality. It should be a sigma delta type.
Is this a hardware limitation? Yes. As far as I know are all PIC18 pwm outputs using timer2 as period generator.
Arduino != PIC Almost any PIC can be used although one with a hardware pwm module makes life easier. If that's all it has to do, I suggest using PIC12F683 which has the necessary timers to decode the IR signal and has a pwm module. It only has 8 pins and has it's own internal clock generator so the hardware around it can be very simple. Brian.
I want to generate a digital pwm with a changing frequency and period's duration. Following are the ranges. Frequency : 1Hz to 1000Hz Period's Duration : 50uS to 10000uS Now, frequency is not the hard part. Its the duration thats hard to achieve using arduino. So I'm wondering is there any chip I can buy that can do this pwm which can be set b
Hello, I'm working on a project (theoretical stage right now) and I need some suggestions. I plan to use 6 LED chains of different colors - that's multiple 5mm high brightness LED's wired serially in a single chain (all LED's in a given chain are the same color). Normally they draw about 20mA of current when fully lit, but the voltage needed to
The rotating part of a motor is heavy which causes momentum. The momentum smoothes the high frequency pwm pulses causing the vibration to be very small. Make a motor that is a light as a feather and feed it low frequency pulses. It will vibrate like crazy! The momentum of a DC motor causes it to be a generator when the pwm voltage is (...)
I think that can be easily done using 555 timer circuit. 555 timer is available in somewhere in orcad libraries. Just do web search - "pwm 555 timer" and you'll get lot of links showing how to achieve this.
hello friends i am try to making sine wave inverter by pic16f72. well , i need four output pwm for h bridge driver . my question is how to make pwm four normal i/o .
Hello. I would like to generate 100 kHz pwm signal with attiny26. Please, check my source code, I borow my ISP programmer so I can't do it. Thanks in advance. #include #include #include int main(void) { DDRB |=(1<pwm out PLLCSR |=(1<
i have problem while simulating the pspice model of ir2136 and based inverter with sine-pwm technique with 20khz switching frequency first one is control circuit second one is power circuit 118016118017 my problem is source voltage is short circuiting for a duration around 1micro second the gate vo
Hai all I am new to TL494 pwm generator. I want following requirements dead time = 2usec frequency = 10Khz Please tell me the Values of RT, CT and explain how to set dead time tanx....
Hi, 10MHz triangle or sawtooth generator to one comparator input, analog to the other comparator input, output is pwm. Klaus
I found a web site gives pwm generator with multiple phases output ,however it is supposed the pwm frequency is given , what should I modify the code so that any pwm frequency can input to the vhdl code
This might help you. Also why are you not using mikroC pwm library and vary the duty of the pwm at required intervals using a Timer ?
The shown NCO generates pulses respectively square waves, a sine generator has to be programmed in software. It won't need specific hardware, except for a DAC to output the sine. 15 kHz can be possibly made with a pwm pin and a low-pass filter without a DAC. So if you go for a microcontroller solution, everything is about writing respective softwar
The table shows a full sine period in 8-Bit "straight binary" coding. For some reason, it only spans the range from 0 (sine minimum) to 254 (maximum) instead of 255. I guess this has to do with pwm generator properties. Basically you can code a sine table in any numerical format of your choice, everything depends on the intended usage.
Hi y'all I'm trying to drive the MOSFET directly with the pwm. I generated a pwm signal using dspic30f4011 and because the MOSFET needs atleast 10V to switch on. I then used a MOSFET gate driver (HCPL 3120) to boost the voltage. I get a nice clean gate signal but immediately when i connect the pwm signal to the MOSFET the gate signal (...)
Hi Nick. Are you trying to produce a pulse, or a sine wave? Are you converting the pwm output back to analog with a filter? You have two basic controls on a pwm: frequency and duty cycle. Generally with a micro you control these by setting the clock source and frequency, total pwm cycle period (or timer overflow counter in clock (...)
For the isolation sake, you could build the simplest flyback/forward converter with two (identical?) secondary windings. All you need is a cheap MOSFET switch, a small ferrite core and a LM555 as a pwm generator. Of course, you also need two rectification diodes and capacitors but it's an economical solution anyway.
CPU Fan controller using PIC16F877A pin CPU Fan controller using PIC16F877A micro controller. 25 Khz pwm generator, RPM Meter, and Button switch Speed adjust. obrazki.
Had you considered to employ some online pwm calculator for PIC16F family such as this one bellow ? PIC pwm Calculator & Code generator +++
I want to know the various ICs that can be used to generate pwm sine wave. I was able to get one on google but not with much design support. HT1112 IC. Please help me out. I dont really want to deal with programming microcontrollers as I do know they can be used. if you are looking for a sine wave generator DDS chips
Well the principal to do this is and a sine wave with a triangle or evan a sawtooth signal the result is pwm well there is many types you must be more specific, like:
Hi All, A very quick and daft kind of query. I'm trying to actuate a solenoid with pwm. I tried searching about it but couldn't get exactly what I want. Its quite simple though. I've got a function generator, GwInstek AG-2005. I want to run this solenoid at certain parameters. I simply hooked it up to the output of the Func Gen thinking it would
Obviously the three inverters must be synchronized, usually driven by a common signal generator. For details we need to know how the inverters are driven (e.g. digital signal generation, analog pwm generator, etc.). Examples of three phase inverters have been published at edaborad and an be found on the internet.
No, you can't "use pwm generator to control rotation speed". Since pwm is a CONSTANT FREQUENCY, if you use the pwm output you will get a CONSTANT SPEED. That's not what you want. Remember, pwm varies the duty cycle, not the frequency. As far as the rest of your questions, there no way to answer them-it (...)
Hello all, there are some micro-controllers with COG or complementary output generator to create a complementary pwm signals. I do understand how to create them and etc but do not know whats their use in real life applications and use of dead bands etc. I may sound like a newbie but after searching on google i could only find that these type of PW
Hello, I want to produce a pwm/pulse train with 125 kHz frequency and a 35% Duty. This is my simple schematic and I followed the formula 1.72/RC from the appnote of can vary my output's frequency but I can't seem to find a way to obtain my desired duty cycle. I can't find any formula for the Duty
Most of these circuits with IGBTs (or power MOSFETs) operate on the principle of pwm. Somewhere in the circuit there is a comparator working as a ramp generator, and somewhere in the circuit there is a comparator generating pwm for IGBTs. This comparator needs a dc voltage reference. And that is where you can inject the control voltage from (...)
All, I am working on 2-phase interleaved bidirectional dc-dc converter as shown in the circuit below. I have not been able to find answers to the following questions running through my mind. The questions are: 1. How do I generate two independent pwms of 180 degrees out of phase with dead time? In this case considering 50 kHz switching frequ
I've never heard the term 'Worldclock" used before but from a technical viewpoint, a randomly hopping frequency generator shoulds be fairly easy to make using a small microcontroller running a software routine. As you are only looking for around 2KHz shift, it should be possible to use timers, pwm or even just toggle a pin to produce the signal.
Adding a couple more transistors to my discrete linear generator, we have a discrete pwm ;-) What can I say? I like discrete stuffs 8-)
Can anybody help me explain with the use of an 555 timer IC in designing a digital sensor with a modulating sensor? I do not know what you call a "digital" and "modulating" sensor. The 555 timer can be used as a timer, an astable or monostable multivibrator, a pwm generator, etc. Please explain exactly what you need.
Hello I have already designed a pwm based 3-phase sine generator . pwm freq = 16KHZ The bridge stage is 3 nos Dual IGBT modules with 10000uf/600v electrolytic capacitor across the input to the bridge and 3 nos 0.22uf/600v capacitors across each module. I have attached the waveform across R-Y phases and i see a lot of oscillations (...)
The tl494 is a veritable chip. If you need switchable output voltages then you could use transistors to switch in and out resistors to ground on the feedback loop, or if your using the chip as a pwm generator switch resistors to ground from pin 3. Or if you want to be clever you might be able to use the vref block within a pic instead of the vref
i have to generate a pwm using ccp module from an analog signal varying between 0-5volt. i have combined adc and ccp programs... there is a problem wen i checked it in proteus... e.g if i give 2.5 volt, i will get 50%duty cycle, but after that if i change voltage to 1.25volt, i am not getting 25%duty cycle... if i reset , then i will get 25%. that
Usually pwm ic S3525 circuit is connected with battery so it needs isolation. This isolation is provided by the transformer. On the secondary side is 311V DC and 220V AC generator circuit which has mcu, does not require isolation. If you require isolation there too, hi speed optocouplers are required. A pulse driver transformer can also be used and
Hello every body,can some body help me to generate a pwm signal on the two pins of PIC16F1827;I want to use those signals for controlling my two IGBT which makes a half wave DC/AC Converter. As hope you get the point those two signals might be in phase shift of 180 degres for making a complete alternative signal. Thanks for the help.
Hello there, I'm using the dsPIC33fj256gp710 MCU to obtain the pulse width of a pwm generator using Input Capture module(rising and falling edge of the pulse). The program works fine, and I can obtain a time period. However, I need to do some further calculations with the period value, and I don't really know how to convert the obtained value
I am working on a project which is Automatic voltage regulator of fenerator using field contol through pwm problem is what should be the frequency of pwm generator draws 1 A at 50v dc field at full load and 0.5 A 19 v at no load. my idea is to choose a mosfet and a diode to prevent transients. pwm directly from (...)
hi everybody following program is written for dspic33ep256mu806 by microC pro for dspic . the purpose of program is generating pwm output. in my program pwm generator 1 is set to work and independent interrupt for pwm generator 1 is set to work . pwm generator 1 is work (...)
Hi, Attached is a part of the schematics of the board. DO_TEC_HS and DO_TEC_LS are coming from microcontroller at level 3.3V. My question is when the microcontroller gives a 3.3V,8KHz signal to DO_TEC_HS pins, can the bootstrap circuit handle the speed it? The Vin to this circuit can be from 16v to 60V. If the DO_TEC-HS is 3.3V (continuously
i wrote a code to capture a pwm signal using codevision it works but i want more accuracy any suggestions!?!??! /***************************************************** This program was produced by the CodeWizardAVR V2.05.3 Standard Automatic Program generator ? Copyright 1998-2011 Pavel Haiduc, HP InfoTech s.r.l. www.hpinfotech.
Please can anybody help me about how to generate 120 deg phase shifted pwm waveform for ac motor control?
Hello I want to implement a multiphase buck converter using a micro controller My buck converter converts 12V to 1.2V at 12A switching frequency 500Khz I went through TI and Microchips micocontrollers I require 2 ADC and DAC and probably 8 pwm generator modules i think and 4 opamps and comparators I am having difficulty in deciding the micocon
This simple circuit based on Atmega8 can be useful as a generator of pwm signal for example of a radiator fan driver. Potentiometer is used for smooth regulation of the fulfillment from 0 to 100%. The current setting
RS-232 is the standard for serial communication. Are you receiving some required frequency input serially??? And based on that value you want to generate the frequency by calculating the PR2 value??? If you are going for the serial input then follow these steps, 1. Make sure you first convert it from ASCII to integer value.. 2.Use PR2=(P
Hello friends, I am experimenting with using buck/ boost converters with various power supplies in Simulink . The problem I am encountering is regarding the connection of pwm generator with the Mosfet Gate terminal in the Boost converter. I have tried many time through various methods, but somehow I cant manage to give pwm signal to the (...)
How many steps are you going to use? Will you have just 50% duty cycle or will you vary duty cycle as well? Have you gone through the datasheet and taken a look at the CMO module and the pwm modes of operation? If not, here's the datasheet:
I must move to Serbia, mine is 0.6eur/1KWh. A typical month is 400eur ! The schematic says it's pwm but it's just a square wave generator, not even modified sine. It would be very inefficiant. Brian.