Using a microcontroller input as crude comparator (threshold variation effects)

Started by Klaus Kragelund in sci.electronics.design9 years ago 19 replies

Hi I am working on a current mode controlled SMPS. I have a sawtooth voltage r= amp (measured current in a sense resistor) and I would like...

Hi I am working on a current mode controlled SMPS. I have a sawtooth voltage r= amp (measured current in a sense resistor) and I would like use a digital i= nput pin of a micrcontroller to turn off the PWM that controls the ramp. Th= e ramp moves from 0 to 100mV in 10us.=20 I do not have a free comparator on the micro, so I thought of using the dig= ital input threshold as the fast level...


Current State of ASIC, do or dont

Started by Klaus Kragelund in sci.electronics.design7 years ago 49 replies

Hi We have a very high volume circuit, used in several product, about 1mill pcs per year. Another more complex circuit go at 100k pcs per...

Hi We have a very high volume circuit, used in several product, about 1mill pcs per year. Another more complex circuit go at 100k pcs per year The circuit is a mix of digital functions, small signal transistors, some high voltage stuff ( < 30V) and PWM controllers for SMPS I need some input to how the ASIC marked is today: 1. NRE costs 2. What is relevant to implement into an ASIC 3.


nonlinear HBridge effects in BLDC control

Started by alb in sci.electronics.design7 years ago 7 replies
PWM

Hi everyone, I have a PI controller which drives a PWM unit switching an Half H-Brdige stage to control a phase of a three-phase BLDC motor....

Hi everyone, I have a PI controller which drives a PWM unit switching an Half H-Brdige stage to control a phase of a three-phase BLDC motor. This loop regulates the current, while an outer loop control the speed to follow an external profile (through encoder readings). I've tuned the controller in order to meet some requirements on the time response (risetime, steady-state error, ove...


Improve PWM outputs with S/H?

Started by whit3rd in sci.electronics.design4 years ago 24 replies

A simple timer can set a pin HIGH for N clock cycles out of 1024, then LOW for 1024 - N clock cycles. That output pin, with some RC filtering,...

A simple timer can set a pin HIGH for N clock cycles out of 1024, then LOW for 1024 - N clock cycles. That output pin, with some RC filtering, generates about the same range and precision of voltages as a 10-bit DAC. But, cheaper. It also has ripple, because the filtered output ramps UP while the pin is high, and DOWN while low, dithering around the intended value, in addition to slowly ...


MOSFETS and H bridge

Started by Jessica Shaw in sci.electronics.design10 years ago 13 replies
PWM

Hi, I am using HIP4081A to drive an inductive load. I am controlling the HIP chip with a microprocessor using PWM. The power supply of the...

Hi, I am using HIP4081A to drive an inductive load. I am controlling the HIP chip with a microprocessor using PWM. The power supply of the chip is +12 Volts. The HIP Chip is driving the H bridge made with four NMOSFETS (IRF540N) HIP chip is driving the NMOSFETS which in turn injecting the current into the load and the voltage is appearing across the load as a sinusodial waveform of fre...


Trying to identify SMD with label scrubbed off - PWM, inverter, 100W 12VDC to 120VAC modified sine wave

Started by John Robertson in sci.electronics.design4 months ago 35 replies

I have a trick on-topic question, looking for possibilities for candidates for a 16-pin SMD device that has these pin outs identified so...

I have a trick on-topic question, looking for possibilities for candidates for a 16-pin SMD device that has these pin outs identified so far: 1 & 16 - RC oscillator 4 - ground 7 & 8 - drivers for a "H" style MOSFet set of four transistors that between them generate a modified sine wave running at 60Hz and 120V. So it is NOT a TI SG3524/3525 chip. The MOSFets generate the pow...


Re: Need PWM controller for current source to charge 48v lead acid.

Started by Sjouke Burry in sci.electronics.design9 years ago 24 replies

Yzordderrex wrote in news:1b7567ab-9638-45dd-8366-872c961e58e6@googlegroups.com: > Greetings, > > I have a small diesel engine...

Yzordderrex wrote in news:1b7567ab-9638-45dd-8366-872c961e58e6@googlegroups.com: > Greetings, > > I have a small diesel engine spinning a DC generator. I need a > control chip that will take approximately 60v that generator puts out > and charge the lead acid bank. Bank is 16 27M Die Hard deep cycle > wired in 4x4 configuration. It is my intention to cont


Op-Amp Sawtooth Generator

Started by Patrick Chung in sci.electronics.design8 years ago
PWM

Op-Amp Sawtooth Generator is unavoidable part of PWM modulators and so part of analog control circuits. Now it can be...

Op-Amp Sawtooth Generator is unavoidable part of PWM modulators and so part of analog control circuits. Now it can be simulated: http://www.cirvirlab.com/simulation/op-amp_sawtooth_generator_miller_integrator_simulation.php Also read the theory of operation: http://www.cirvirlab.com/index.php/tutorials/135-op-amp-sawtooth-generator-miller-integrator.htm l


Op-Amp Sawtooth Generator

Started by Patrick Chung in sci.electronics.design8 years ago
PWM

Op-Amp Sawtooth Generator is unavoidable part of PWM modulators and so part of analog control circuits. Now it can be...

Op-Amp Sawtooth Generator is unavoidable part of PWM modulators and so part of analog control circuits. Now it can be simulated: http://www.cirvirlab.com/simulation/op-amp_sawtooth_generator_miller_integrator_simulation.php Also read the theory of operation: http://www.cirvirlab.com/index.php/tutorials/135-op-amp-sawtooth-generator-miller-integrator.htm l


"Bogo process"/plant transfer functions for PID testing

Started by bitrex in sci.electronics.design4 years ago 16 replies

I'm looking for a "bogo process" transfer function for a PID loop plant. That is to say something that's not real hardware but just so I can...

I'm looking for a "bogo process" transfer function for a PID loop plant. That is to say something that's not real hardware but just so I can calibrate the software/ensure that the loop is generating sane values prior to connecting it to a real plant and working on tuning. The "bogo loop" would just be say PID core -> PWM output/DAC -> analog filter -> back into uP via ADC -> digital fil


Is there a 555 timer with a high Z Control Voltage pin

Started by Mike Perkins in sci.electronics.design3 years ago 11 replies

The normal 555 timer has Control Voltage pin that is intended to be decoupled to ground. For voltage controlled PWM circuits this pin is...

The normal 555 timer has Control Voltage pin that is intended to be decoupled to ground. For voltage controlled PWM circuits this pin is driven but must obviously be from a low impedance source. Most datasheets don't even qualify this input resistance and was wondering if anyone knew of an IC with the same features as a 555 but where the Control Voltage input pin is high impedance? -...