If a heater is controlled by turning it on and off, does a PID algorithm help in more closely controlling the temperature? Will running the...

If a heater is controlled by turning it on and off, does a PID algorithm help in more closely controlling the temperature? Will running the PID loop faster than the temperature measurement improve anything? How would a PID control be an improvement over a simple temperature comparison with or without an anticipator? -- Rick

I'm working on a digital PID motion controller. The target/goal is to move at (very) constant velocity. Position feedback is from a linear...

I'm working on a digital PID motion controller. The target/goal is to move at (very) constant velocity. Position feedback is from a linear encoder with quadrature output. The input to the controller is a linear ramp (i.e. constant velocity) and the PID changes the motor output to minimize the error. The system works, but I'm looking to improve its performance at low velocities. At low...

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

Yet another video on tuning PID controllers has been tossed into the YouTube pool. ? https://youtu.be/drYO60z6_h4 -- Tim...

Yet another video on tuning PID controllers has been tossed into the YouTube pool. ? https://youtu.be/drYO60z6_h4 -- Tim Wescott Wescott Design Services http://www.wescottdesign.com I'm looking for work -- see my website!

I have a program being ran every 20 milliseconds and I'm trying to implement PID control. So P = SetPoint - Actual, I = I + P ? , and D = P -...

I have a program being ran every 20 milliseconds and I'm trying to implement PID control. So P = SetPoint - Actual, I = I + P ? , and D = P - Old_P???? On D, should "Old_P" be from the previous round or should it be a value from a certain length of time ago? Also, is "I" just summed up or is it the sum of I over a certain length of time? I'm trying to find out if I need to set up a...

I know many of your old farts here have a collection of schematics or at least manuals.... I can not find the manual or maybe even the...

I know many of your old farts here have a collection of schematics or at least manuals.... I can not find the manual or maybe even the schematic that sometimes comes with these manuals for a : Fincor 105456401 , 1900-77 This is a PID dancer controller with a tach following option. If need be I can reverse engineer one using TinyCad or some common free electronic ...

I understand the basics of PID design, but if you can't describe the thing being controlled, how can you design the controller other than trial...

I understand the basics of PID design, but if you can't describe the thing being controlled, how can you design the controller other than trial and error? The "plant" is a motor on a tall reducing gear (~300:1) turning an arm that presses on a bag producing an air flow with the loop controlled by a pressure measurement. One issue I'm seeing discussed is a tradeoff on the

Hi, Can a partial differential equation be numerically calculated to give a function that is equivalent to a PID loop for controlling a...

Hi, Can a partial differential equation be numerically calculated to give a function that is equivalent to a PID loop for controlling a multivariable system (ie a lunar lander with yaw/pitch/thrust to land on a given X/Y coordinate from a given altitude)? Do partial differential equation solvers ie for the heat equation, also work for large numbers of variables, ie 10? Is this method ...

Hi guys/gals. A bit of a problem has caused me to revisit PID/ PI controll= ers and tuning. I have this nice paper on the Ziegler=96Nichols...

Hi guys/gals. A bit of a problem has caused me to revisit PID/ PI controll= ers and tuning. I have this nice paper on the Ziegler=96Nichols tuning me= thod that compares the closed loop period to the open loop step response of= the system. It then shows the closed loop step response for different tun= ing parameters. But I can=92t seem to lay my hands on it... grumble. I=92= ll keep se...

https://www.youtube.com/watch?v=JVqJ7uRGwoA -- Tim Wescott Control systems, embedded software and circuit design I'm looking for work! ...

https://www.youtube.com/watch?v=JVqJ7uRGwoA -- Tim Wescott Control systems, embedded software and circuit design I'm looking for work! See my website if you're interested http://www.wescottdesign.com

Embedded Systems Design (or whatever they call themselves) kept moving this around -- so I've revamped it, updated it, and posted it on the...

Embedded Systems Design (or whatever they call themselves) kept moving this around -- so I've revamped it, updated it, and posted it on the web. Take a gander. Please comment on anything you like/don't like. I'm not sure if the way that I'm setting off the math is a Really Good Idea or a Really Bad Idea -- I'm trying to make it easy for the math-averse to skip over it, without breakin...

We have some devices that have been in use for many years (not made by us). These are analog PID boards that employ a 324N chip. The...

We have some devices that have been in use for many years (not made by us). These are analog PID boards that employ a 324N chip. The circuit works very well and is very flexible in what it can do. THis is the problem. Lately been getting a few random failures of the op-amp. Today, one failed simply by turning one of the pots on the board that is in the feed back loop as the GAIN con...

Imagine a mass that we want to heat with some closed-loop controller. It's C2 below. Voltage represents temperature. Thermal systems...

Imagine a mass that we want to heat with some closed-loop controller. It's C2 below. Voltage represents temperature. Thermal systems are diffusive, which we represent as a bunch of RC lags. Assume the voltage at C4 is the temperature sensor. If I were to design a PID controller, I'd have to really think about it, or fiddle some, to keep it stable. But if I do a dumb on/off thermostat, ...

Hi guys, I'm trying to measure resistance, current, and voltage of a resistor (heater) connected to a 0-24V @ 3A transformer. The heater's...

Hi guys, I'm trying to measure resistance, current, and voltage of a resistor (heater) connected to a 0-24V @ 3A transformer. The heater's consumption is actually 2A max., and I'd be controlling it with a triac driven with an 8-bit micro, which I'd also use to get the above readings and send them to the host. This is my initial layout: https://docs.google.com/viewer?a=v&pid=explorer...

https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxyc3RldmVzY290dHxneDo1NjQ1Z TI1ZTY2MWFiM2Yz This had been discussed some...

https://docs.google.com/viewer?a=v&pid=sites&srcid=ZGVmYXVsdGRvbWFpbnxyc3RldmVzY290dHxneDo1NjQ1Z TI1ZTY2MWFiM2Yz This had been discussed some time ago. There was a lot of bragging about being able to create a model, but nothing came of it. Fortunately, this guy had beaten us to the punch, and released this paper publically. The design with multiple time constants makes me think of appro

I was trying to turn a previous SV filter into a notch, (Freq ~3.3 kHz, Q~10-20, see my mech. PID thread.) I was thinking of just subtracting...

I was trying to turn a previous SV filter into a notch, (Freq ~3.3 kHz, Q~10-20, see my mech. PID thread.) I was thinking of just subtracting the BP from the input. But almost all the web stuff I could find said add the HP and LP. (That seemed crazy to me, at high Q both those are peaking.. but then again the SV filter seems a bit crazy to me... two integraters in a row, come on. :^) S...

I know about the auto-tuning algorithm for PID: cycle the temperature up an= d down, measure the peaks and distance between the peaks, and...

I know about the auto-tuning algorithm for PID: cycle the temperature up an= d down, measure the peaks and distance between the peaks, and calculate Kp,= Ki, and Kd. =20 But recently I've been experimenting with what Phelan called PDF, and am in= trigued by it. There isn't a lot of information out there about it, but ne= arly everyone that's used it has good things to say. =20 The prob...

I just found out... Tom Frederiksen, RIP... Tom and I shared a cubicle at Motorola Semiconductor Products Division during the early to...

I just found out... Tom Frederiksen, RIP... Tom and I shared a cubicle at Motorola Semiconductor Products Division during the early to mid-60's. ...Jim Thompson -- | James E.Thompson | mens | | Analog Innovations

The oops is for stepping on Al's PI thread. Here (again) is the response, of my piezo/ aluminum flexure mount/ grating. (I'll post a pic,...

The oops is for stepping on Al's PI thread. Here (again) is the response, of my piezo/ aluminum flexure mount/ grating. (I'll post a pic, Thursday) https://www.dropbox.com/s/zftwx11a36zkypp/PIEZO-RESP.BMP?dl=0 The peak may be a little higher than shown, I cut the input by a factor of 2 for the highest peaks.. and the peak was clipping again. (If I drive the piezo too far the l...

I'm going to be using ULN2803APG in a design of mine, and I just noticed on the datasheet [1] that Vce(sat) typ is 1.3 at 350ma. Does that...

I'm going to be using ULN2803APG in a design of mine, and I just noticed on the datasheet [1] that Vce(sat) typ is 1.3 at 350ma. Does that mean that the voltage drop across the Vce will typically be 1.3 at that current? Or does that mean the voltage for Vbe needs to be that high to have saturation? [1]