Hello, I'm trying to make 3 PWM circuits to control 3 different thermoelectric coo= lers (peltier cooler) I'm aware that ideally you...

Hello, I'm trying to make 3 PWM circuits to control 3 different thermoelectric coo= lers (peltier cooler) I'm aware that ideally you shouldn't run these with a PWM, that's fine, and= I'm only using these in one direction, only as a heater. So I made a simple PWM, with a Linear Tech. PWM part, a high side FET drive= r and a FET. and the thing works ok for 1 heater, but once I plug t...

Hi everyone, I've an half H-bridge motor driver controlled via a PWM. We read current on the phase terminal and regulate the PWM accordingly...

Hi everyone, I've an half H-bridge motor driver controlled via a PWM. We read current on the phase terminal and regulate the PWM accordingly through a PID. The exercise is to play with all parameters (transfer function, sampling frequency, adc resolution, pwm resolution) in order to get the right precision on the output. I wanted to model the loop with something like MATLAB or Octav...

Does anybody make an IC that takes I2C command and outputs duty cycle (PWM)? I need to control bunch of TECs from CPU and I2C-> PWM seems the...

Does anybody make an IC that takes I2C command and outputs duty cycle (PWM)? I need to control bunch of TECs from CPU and I2C-> PWM seems the most efficient (and smallest) way to do it. Any suggestion will be appreciated. Thanks Michael

I have a FET and a load and a micro outputting PWM. I want to convert the PWM to DC (low-pass filtered?) which will control the current...

I have a FET and a load and a micro outputting PWM. I want to convert the PWM to DC (low-pass filtered?) which will control the current through the FET. I also want to be able to calibrate the DC voltage such that for any given PWM duty-cycle I want to be able to adjust the resulting DC voltage plus or minus a yet-to-be-determined percentage. This will probably need to be done only...

Hi all, I want to make a V to PWM circuit. (For a servoed heater.) I drew a triangle wave into a comparator, and that seems simple enough. ...

Hi all, I want to make a V to PWM circuit. (For a servoed heater.) I drew a triangle wave into a comparator, and that seems simple enough. Though it will take a few IC for the triangle wave. (I guess I could use an opamp and dual comparator.) So I went searching for V-PWM IC's. Most are for SMPS controll, which seem overly complicated for what I want. I also want a fairly low...

Seems like every time I start a new power design, I waste a bunch of time looking for the ideal PWM controller. At the end of the day I'd...

Seems like every time I start a new power design, I waste a bunch of time looking for the ideal PWM controller. At the end of the day I'd really like to have the simplest IC possible to handle just the PWM function, and I provide my own error amp, gate driver, and reference externally. The ideal part would look like this: oscillator set by resistor, comparator non-inverting input,

I need an isolated analog output (many of them, actually) with, say, 1 PPM programmability and linearity. An optocoupled DAC would be...

I need an isolated analog output (many of them, actually) with, say, 1 PPM programmability and linearity. An optocoupled DAC would be silly, so I'll use PWM. https://dl.dropboxusercontent.com/u/53724080/Circuits/PWM_WB_P470.JPG If I start at 200 MHz, and do a 20 bit (1 PPM) pwm, the output frequency would be 200 Hz. If I use a 3-pole lowpass filter (not too much delay) it has to be -...

How much more efficient is PWM over ordinary dc? eg in terms of battery useage, can I double the life between charges? Hardy

How much more efficient is PWM over ordinary dc? eg in terms of battery useage, can I double the life between charges? Hardy

Folks, Does anyone know an IC that can turn a control voltage into PWM and can handle PWM frequencies in the 50-1000kHz range? Similar to a...

Folks, Does anyone know an IC that can turn a control voltage into PWM and can handle PWM frequencies in the 50-1000kHz range? Similar to a class D driver but has to go down to DC. The changes in control would be restricted to the audio spectrum below 15kHz. The LTC6992 does this nicely but isn't precise enough. Same with 555-style timers or switcher chips. I am looking for better 1% and...

Can an RMS current clamp meter accurately measure the current of a PWM voltage? How else to measure PWM current without a shunt or direct...

Can an RMS current clamp meter accurately measure the current of a PWM voltage? How else to measure PWM current without a shunt or direct in-line meter? Thanks.

Could some electronics guru please clarify the following. I understand that Pulse Width Modulation (PWM) uses a high fixed frequency carrier...

Could some electronics guru please clarify the following. I understand that Pulse Width Modulation (PWM) uses a high fixed frequency carrier signal (e.g., triangle wave) and a low frequency modulation signal -- or even a DC level. If I were to use PWM for motor control, and use a fixed frequency triangle wave carrier, what would be the modulating signal in this case ? Is the output PWM sig...

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...

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 would suit if it were voltage controlled instead of current. I've gone through Fairchild, ONsemi we...

Hello, I am trying to simulate a buck and a boost converter using Christophe Basso's generic PWM models (in LTSpice) for voltage mode...

Hello, I am trying to simulate a buck and a boost converter using Christophe Basso's generic PWM models (in LTSpice) for voltage mode controlled and current mode controlled switched mode power supplies. These models have an integrated PWM generator and power switch. These models can be found here: http://cbasso.pagesperso-orange.fr/Downloads/IsSpice/Final%20models.zip (alternati...

Hi I am working on a small 100mW forward converter and I need a very low power PWM control. So the 555 comes up, along with some ultra low...

Hi I am working on a small 100mW forward converter and I need a very low power PWM control. So the 555 comes up, along with some ultra low power opamps. But, isn't there a PWM chips out there with low operating current. Sofar I found the TPS5110 with sub mA current consumption: http://www.ti.com/lit/ds/symlink/tps5110.pdf Anyone used one with lower current? Thanks Klaus

Dear All, I am building a PWM Sine Wave Inverter using H-Bridge IGBT Configuration. The inverter has the following stages: 1. A Sine Wave...

Dear All, I am building a PWM Sine Wave Inverter using H-Bridge IGBT Configuration. The inverter has the following stages: 1. A Sine Wave Oscillator 2. An unity gain inverting amplifier to generate inverted sine wave 3. A Triangular wave generator 4. Two Sets of Comparators to generate PWM waveform for positive and negative cycles 5. Two Half Bridge IGBT Drivers to generate A and A' s...

This is more of a practical question. I understand feedback and how it work= s and can design controllers. However, these have been for dc (non...

This is more of a practical question. I understand feedback and how it work= s and can design controllers. However, these have been for dc (non PWM) mot= ors using tachos with a dc output. What I want to know is how you achieve this with digital tachos which give = out pulses.=20 I am thinking that the set point is still dc as before (or software based) = and you just count the pulses f...

I have a DC contactor with a coil that draws about 4 amps at 24 VDC and=20 normally uses an economizer resistor of about 75 ohms to reduce the...

I have a DC contactor with a coil that draws about 4 amps at 24 VDC and=20 normally uses an economizer resistor of about 75 ohms to reduce the = current=20 to about 400 mA when pulled in (controlled by a delayed contact). But I = want=20 to use a PWM drive for another similar contactor (actually a 120 VAC = unit)=20 so it will work on DC and thus be more tolerant of AC line brownouts. Pr...

I am using an FTDIchip which is the FT245R, i was able to connect and write to the device. And the aim to be able to creat PWM on any of...

I am using an FTDIchip which is the FT245R, i was able to connect and write to the device. And the aim to be able to creat PWM on any of the Data PINs and control it with a Trackbar. I have tried writing 1's and 0's to create that but have not control of the PIN

I am just reading the first page of the "The x-Chapters" When I read the line: "PWM for dc motors - a myth demolished" a thought pop out of...

I am just reading the first page of the "The x-Chapters" When I read the line: "PWM for dc motors - a myth demolished" a thought pop out of my brain: There is something missing: The peltier element - how to avoid PWM and ripple. Fun with PIR sensors - what you should do and what not. The LM741 - please dont use it anymore. :-) Any other ideas for topics we realy need? Olaf ...

Hello, all, I have been using metallized polyester film capacitors in the output filter of a PWM servo amplifier. I recently discovered that...

Hello, all, I have been using metallized polyester film capacitors in the output filter of a PWM servo amplifier. I recently discovered that when the PWM duty cycle is near 50%, these caps can get quite hot. Perusing the data sheet, it appears that I am running above the manufacturer's current rating in that condition. Can anyone recommend a capacitor around 10 nF and 250 V DC rating t...