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Sci.Electronics.Design is a worldwide Usenet news group that is used to discuss various aspects of Electronic Circuit Design.
We found 446 threads matching "pwm"
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The most relevant threads are listed first
PWM and dither
Pasquale - 2008-03-09 21:14:00
Hi,
I need to control a solenoid valve using PWM but I have also some
specifications about "the dither" in order to reduce friction etc.. I now
what the dither is able to do in theory. I now how to built an electronic
circuit concerning PWM (I'd do that using a micro plus a MOSFET etc.) but
...
Converting PWM to Analog
2008-03-03 19:00:00
Hi all,
Currently, I have a microcontroller that puts out a 1000Hz signal but
the low-pass filter I have built only converts PWM to analog for a PWM
carrier frequency of about 10kHz. Is it possible to adjust the PWM
frequency that will work for the filter? I'm using a 3rd order, op-amp
LPF, s...noisy logic
Jon Slaughter - 2008-09-23 16:22:00
I have some logic wired up on a breadboard that is 2 input 4 ouput logic.
When one of the inputs is constantand not noisy one of the output's is
suppose to be constant but there is a lot of noise on it.
an example is
PWM in and ~F/B in -> out
So somehow the PWM signal is "getting" thro...RMS approximation of Square/PWM signal
JMini - 2008-06-22 19:17:00
Does anyone have a way to approximate and RMS voltage from a PWM signal.
I want to regulate the RMS voltage sent to a lightbulb, but do not have the
room for the inductor and capacitor required to carry 20+ amps of current. I
need to feedback a voltage to the PWM controller that is proportional t...PWM detector?
2008-11-30 20:39:00
Hello all,
I am designing an automotive product (operates 9 to 16VDC) that will
drive a regulated high current 10 amp load with a NPN low side drive
transistor. It will maintain average current to the load via PWM
(400Hz 1% to 99% duty cycle) and sense resistor.
My question, I want a way t...Wanted: Voltage mode PWM controller
powerampfreak - 2009-03-27 01:52:00
Hi all. I need a basic voltage mode PWM controller for a buck
converter project. I need a wide duty cycle range, like 5 - 95%. I
don't need an error-amp in the ic, since this part is placed elsewhere
in my circuit.
So, a basic Ramp generator and a PWM comparator, and an output stage.
An UC3843 ...PWM dsPIC33F
Pasquale - 2008-05-21 10:03:00
Hi all,
I'd like to connect the output of my dsPIC33F (PWM) to an optocoupler
(TLP550). The maximum current which can sinks/drains the I/O pins is 4mA.
What do you suggest me ?
Thank you,
Pasquale.
...noise from pwm
bob - 2008-02-14 04:46:00
I have a pwm that takes AC from the wall, and without an isolation
transformer, turns it to a ~+-170V switching supply. I'm using the pwm
to power a custom device (about 6ohms and 0.15H). The problem I'm
having is that there is noise everywhere. Specifically I have a hall
effect current sensor w...A multi processor PIC computer :-)
Jan Panteltje - 2010-06-09 10:18:00
A multi processor PIC computer :-)
ftp://panteltje.com/pub/multi_processor_PIC_LED_color_controller_hardware_img_2002.jpg
I modified my LED color controller a bit so it has 3 independent hardware PWM channels.
One PIC is the master, is controlled via ethernet, and its PWM unit drives blue.
It...4-pin pwm fan.
2008-01-30 19:29:00
I work as a coputer tech (fixing pcs) in a major university as part of
a work study program. Im also a junior in computer engineering, so I
know my way around a breadboard.
One of the machines is a newish dell btx, that's having major cooling
problems (random page faults, hd temp goes up to a...PWM MOSFET driver question
Richard Rasker - 2008-02-11 06:56:00
Hi all,
I'm currently designing a full-bridge PWM controlled DC motor driver with a
24V/10A supply voltage. For driving each MOSFET half-bridge, I selected the
LM5106 driver IC.
As the '5106 is only available in a 20mil lead spacing MSOP, I can't do any
bench tests without designing a PCB r...Need help identifying thie PWM chip
mook johnson - 2009-07-17 21:21:00
I have piece a datasheet from a PWM chip and would like to identify the part
number.
Its an old voltage mode 16 pin dip part for half/fullbridge.
It has a 4V built in reference (wide tolerance).
Uses a resistor strap to set the PWM freq up to 1MHz.
Bi-Cmos
Has a Ct and DIScharge pin on th...Re: Heatsink for DPAK
Pasquale - 2008-05-29 11:19:00
On Thu, 29 May 2008 12:22:29 +0100, Eeyore wrote:
> Pasquale wrote:
>
> > I know, more or less, how much power my device will dissipate. For the
> > MOSFET should be something like Pd = Rds_on*I^2. For this reason I'm
> > trying to understand how to choose the right heatsink,
>
> I...Using a PIC for a 10MHz divide-by-n counter?
vkj - 2009-10-19 23:39:00
I need a 50% d.c divide-by-n counter running at a fixed input, providing
10MHz/n, n=1..2^21. I was hoping to find a HC logic chip that does this,
but cant seem to find any. The 292/294 need n > = 4. The 4059 dos\esnt
seem to give a 50% dc. Is there any other chip that would work?
Another ide...Electronics and barter?
Jan Panteltje - 2009-02-08 06:08:00
I was just reading an article in the NYTimes about Russia,
where there seems to be a new era of barter between companies,
now that the financial crises has hit there too.
So how about my PIC PWM design against your car?
That article mentions trading underwear for cars! And food!
In itself it ...pwm audio out PIC
merco - 2008-10-22 02:23:00
Hi i had to build a LPF for a PWM audio signal (voice 4Khz, carrier
16Khz) to use with a Max4364 (http://www.maxim-ic.com/quick_view2.cfm/
qv_pk/3536).
My design is a passive filter (pi-greco style C100n-L8.2m-C100n).
I heard a background noise and a scratch every time the sound starts.
I...Slope Compensation Current Mode PWM
2008-07-17 08:53:00
I'm trying to reverse calculate the resistors used in a slope
compensation network on a UC3843N current mode PWM controller (i need
to change the current limit). Does anyone know of any material that
explains it.
I've read some app notes from unitrode and texas, but they refer to
different to...An inverter Re: About a simple class D amp
Gaetan Mailloux - 2009-03-09 11:34:00
Hi
I was, since few months, looking for an easy to build PWM inverter, and
without any PIC programing.
Looking again at the 555 PWM amp circuit, I have an ideas, by merging a
500 w sine inverter with the PWM section of the 555 PWM amp circuit it
made a PWM inverter.
Here is the final cir...Driving many led's (400+)
Jon Slaughter - 2009-01-19 11:45:00
I have an application where I need to drive 400+(~150 rgb's) individually.
I was thinking about using the
TLC5947---TI---24CH 12bit PWM LED Constant Current Driver
as this was the first one I looked at where each LED had it's own channel.
That way I had complete control. It whould require...Active PFC multiphase output question
Scott Ronald - 2008-03-29 20:39:00
I am looking at a multiple boost converter active power factor
correction circuit like below:
vin = 160*|sin(2pi*60*t)|
input filter is a LC lowpass, with cutoff somewhere between 60Hz and F_PWM
|-------------[input filter]-|---[inductor1]--|-[diode]-|---|----|
| ...PWM with low side MOSFET drive for DC motor (coast or brake when off?)
Brandon - 2008-03-20 17:36:00
I need to correct my understanding of a low side MOSFET switching for
a DC motor. I have a DC motor in parallel with a diode connected to
the drain of an n-channel MOSFET on one side (anode side of the diode)
and the motor supply voltage on the other. When the MOSFET is
switched on, the motor ...Understanding PWM of Motor (current problem)
amdx - 2008-12-16 19:40:00
Hi All,
I've been having a discusion about PWM of DC motors on an electric vehicle
forum.
I keep seeing the idea that battery current is different than motor current
when using a
PWM controller. As quoted below.
http://www.4qdtec.com/pwm-01.html This site says this;
"You should see...bidirectional PWM controller
mtech - 2008-05-10 10:58:00
Hello!
I would need an PWM controller for a 24V 50W brushed DC motor. I made one
like on this link, but it's working very bad, it work good when is alive but
MOSFET's gone dead quick.
http://www.ozitronics.com/docs/k166.pdf
Does maybee someone have somethink that could drive mine moto...PWM controller, 0-100%, external VREF?
Rob - 2008-02-02 20:25:00
Hi,
I'm trying to find what I thought would be very simple:
A PWM controller that can do 0-100% Duty Cycle and has an error amp
WITHOUT VREF connected (i.e. I can supply VREF). I've checked every
major supplier up and down with no luck.
I can get around current-mode control by summing ...Re: divide-by-N
Ben Jackson - 2009-08-26 14:25:00
On 2009-08-26, linnix wrote:
>
> Might be difficult to do 10MHz with a PIG^hC.
Not that it's the best solution, but if you use the input as the PIC's
clock and make the main loop something like:
set up pwm
while (1) {
read dip switches
update pwm control regs
}
Well, PIC ...Re: Choosing RC Servo Controller
Phil Allison - 2008-07-17 20:26:00
"Rich Grise"
>
>
> Back in the days before the internet, I had a job to design something
> like this (RC servo controller), I actually went to the Futaba factory
> and asked one of their techs how it was done, and he gave me the whole
> spec. It's PWM at a constant PRF;
** The fac...PWM control
Dave, I can't do that - 2008-07-30 14:27:00
Hi people,
I have an 1992 Synrad laser. I need a PWM controller to set the
intensity. I'd like something that has an input that can be controlled
by a pin on the Parallel port of a computer, but will be happy with a
manual control that I can set for intensity.
Because the laser is so old Sy...Gamma correction and driving RGB color LEDs with PWM from a color table.
Jan Panteltje - 2009-01-25 06:30:00
On gamma correction and driving RGB color LEDs with PWM from a color table.
When we have a PWM system driving red, green, and blue LEDs,
and use a color table to select the color, as I do for example here:
http://panteltje.com/panteltje/pic/col_pic/index.html
then that color table *normally* ...Buck converter, controller riding on the switch node
Klaus Kragelund - 2009-01-16 09:06:00
Hi
Well, a typical buck converter with current mode control has a PWM
controller referenced to output ground, a current sense transformer to
bring down the current sense signal and a pulse transformer to level
shift the gate signal.
Another approach is the one from Fairchild with an integra...I Can Do PIC PWM LED Dimming too :P
D from BC - 2009-02-08 16:31:00
Yeah yeah...PWM LED brightness control with a PIC..
8 channel dimming control
http://www.members.shaw.ca/chainsaw/SED/P1010004.MOV
4.13MB
Save.
Quicktime format.
(VLC media player, MPUI player..etc,)
Coding: assembly language.
I wrote the code.
And designed the circuit.
Now... how do...Incandescent Lamp Resonance
RST Engineering (jw) - 2009-03-25 14:19:00
I've got to come up with a new "automotive" (12 volt automotive type system)
lamp dimmer to replace the old linear design that's been on the market for a
very long time. I'd like to do PWM but I have also seen some PWM designs
where the filament in a small "dial light" type incandescent bulb ...Single Pole Compensating for Sine Wave Generation
Myauk - 2008-09-18 11:44:00
I am studying on PIC Reference UPS design manual
http://www.freeweb.hu/t-t/elokep/pic/download/picref01.pdf.
It explained briefly on the sine wave generation scheme. Reading the
program, I understand that it will start putting 0 on the PWM as duty
cycle first. Then next reference value is look...HBridge motor control
Jon Slaughter - 2008-04-16 02:54:00
Ok, I just thought that I do not need to control the high side of an
H-Bridge?
Essentially the high side needs to be on all the time(obviously the opposite
side needs to be off).
i.e., if its
H1 H2
L1 L2
Then H1 is on, H2 and L1 are off, L2 is PWM.
Obviously to revers...Re: ADC Help
Jamie - 2008-01-20 11:53:00
Baron wrote:
> Hi Guys,
>
> I could use some help understanding Analog Digital Converters. I've
> read a number of articles which helps somewhat.
>
> I want to measure the peak amplitude and duration of a non repetitive
> signal from a transducer. Ideally as a pair of numbers on ...OnTopic: better movie of my col_pic PWM LED controller driven by the Linux xpequ audio processor
Jan Panteltje - 2009-02-17 18:24:00
better movie of my col_pic PWM LED controller driven by the Linux xpequ audio processor
http://www.youtube.com/watch?v=PIGAT1bVRJc
Sound is muted because of copyright....
Who needs speakers ;-)?
Just watch it for a few minutes ..
...170VDC to 12V isolated supply
Jamie Morken - 2008-04-01 20:15:00
Hi,
I would like to make a 170VDC to 12V isolated supply with 12watts
output (12V 1Amp), with 100kHz PWM.
Would a forward converter or a flyback converter (or another) be best
to use for this type of supply?
Also for a 20VDC to 60VDC input to 12V 1Amp isolated output with 100kHz
PWM wh...Alternate methods for driving DC motor
Jon Slaughter - 2008-03-10 22:22:00
I'm curious at to the alternate methods to use for driving a DC instead of
PWM.
Could one use power BJT's as an amplifier also? I was thinking that I could
use 1 BJT and 4 relays where the BJT would control power to the motor and
the relays would control polarity(direction which doesn't cha...Universal PIC switchmode status report
Jan Panteltje - 2009-02-05 11:37:00
Universal PIC switchmode status report
Today added the cycle by cycle current limit,
it is working here, to limit the current to a low value.
cycle_by_cycle_current_limit_current_transformer_img_0891.jpg
Note the small ringcore current transformer in the picture.
The little trimpot was for t...Analysis Of Pulse Width Modulator With Motor Control
seryuz - 2008-05-05 10:39:00
http://img255.imageshack.us/img255/2396/pwmmotorcontrolcr7.jpg
how to analyse the Pulse Width Modulator with Motor control?
How can we make an analysis for this circuit. Can we make something
mathematical? it says:
Designing a PWM Circuit
The concept of PWM inherently requires timing....PCM vs PWM for low distortion sinewaves
BobW - 2008-01-30 01:23:00
I'm attempting to generate low distortion sinusoids (in the 200Hz - 3KHz
range). There will be a fixed number of amplitude changes for each period
regardless of the frequency being generated.
If we keep the number of pulse width or amplitude changes per period the
same (let's say 32 per per...