A filter modifies signals based on their frequency.
2
votes
2answers
132 views
A delta function like response for voltage in to voltage out
I was wondering if anyone knew of a simple circuit design that would output "high" only for a certain voltage (within a small degree of error).
Thanks in advance!
2
votes
1answer
885 views
MATLAB programming of Particle Filter - what is going wrong?
I'm working on a particle filter experiment for multi-sensor fusion and I just programmed it in MATLAB. However, I get very low accuracies for my final values. Plus, I read a lot of literature where ...
1
vote
2answers
541 views
How do I attenuate 30kHz noise?
I'm trying to design an LC low pass filter to attenuate 30-35kHz noise on a 3.3V signal. It's preferable to attenuate higher frequencies as well. So I designed a filter with L=10u, C=1u (which is ...
1
vote
1answer
934 views
Calculating weights in a particle filter experiment using multiple state variables
I am trying to implement a particle filter for coupling gyro and electronic compass for better measuring device orientation. [related question]
I understand my state vector would contain the absolute ...
0
votes
3answers
904 views
Very low frequency (<1Hz) high pass filter design
I want to design a very low frequency (<1Hz) high pass filter. I was thinking of using a 2 pole sallen-key opamp design with a pair of r's and c's. Is there anything special I need to consider ...
5
votes
2answers
189 views
Establishing ground truth in a particle filter experiment using compass and gyro
I'm working on coupling gyro and electronic compass for better accuracy of device orientation (using particle filters). I have one basic question, though: how do I establish ground truth in this case? ...
3
votes
1answer
160 views
How to buy difficult-to-find electronic parts?
A RF receiver project I'm working on calls for a very specific SAW bandpass filter. I've checked all the usual sources here in the US (Jameco, Mouser, Digikey, Newark, etc) without success. What I'm ...
5
votes
2answers
818 views
Shall I use a choke or a bead to filter analog power supply?
Often I have a 3.3V or 5V mixed-signal circuit with a microcontroller running in the 10 MHz range and some analog circuitry, e.g. audio or analog sensor signals, powered from a wall-wart style supply ...
3
votes
3answers
513 views
How to approach designing a 30GHz bandpass filter?
How would one approach designing bandpass filters in the 3GHz - 30GHz range, each with ~2.4GHz bandwidth, for a 50Ω spectrum analyzer or sampling oscilloscope? I've learned how to implement some ...
2
votes
1answer
343 views
LC Filter for Phase Control
Can you point me to a good online resource to learn how to understand and design LC filters?
The goal is digital forward phase control to dim a light bulb. I've read that the EMI produced by the ...
2
votes
4answers
1k views
Low pass audio filter design
I want my Arduino project to listen to the ambient music and sync its light show output to the beat.
It seems that doing BPM detection properly is fiendishly difficult in software, but if your music ...
0
votes
3answers
275 views
Is there a voltage regulator IC that takes PWM input?
I am looking for a small IC that provides a regulated dc voltage based on the duty cycle of the input. This is probably asking for a lot but does anyone know if one exists. Essentially I need a low ...
2
votes
1answer
209 views
Very simple circuit on spice
I have a very simple low-pass filter with an AC source a capacitor and a resistance in series. Now I set C and R so that R*C=100 but when I plot the diagram whit db(out), it looses 3dB at 156Hz ...
1
vote
4answers
114 views
Frequency Filtration
I have a signal that consists of N frequencies all with unknown phase and frequency(N) = frequency(N-1) + 2Hz. I would like to selectively scale the amplitudes of some of those signals in such a way ...
5
votes
3answers
778 views
Does somebody know about a tool to design filters for DSPIC?
I have to make a filter with DSPIC33 and I want a program that design the filter (there are a lot), yet export code to DSPIC (in c, any compiler or assembly).
7
votes
2answers
1k views
Methods of filtering noise caused by DC brush motors
I am looking for any information that would help me reduce the power rail noise and EMI of DC brush motors. I am building a robot that is powered by 2 x 250 W 24V DC motors.
Thank you in advance
37
votes
5answers
2k views
What is impedance?
This is presented as both a resource for the community and a learning experience for myself. I have just enough knowledge of the subject to get myself into trouble, but I don't have the best grasp of ...
3
votes
1answer
486 views
angle calculations
I am using a Freescale 3 axis accelerometer to build a model that flies and would like to log and calculate angles during a flight. My model can both hover and move up to 40kph as well as rotate on ...
6
votes
1answer
395 views
Can anyone figure out this (David Tudor) circuit?
Here's a link to the (crummy) schematic:
It's a filter/phase shift designed by the experimental electronic musician David Tudor, for use in destabilizing audio feedback loops.
The circuit seems ...
4
votes
2answers
383 views
LM13700 Question
I'm currently troubleshooting a state-variable filter I built. All of the filter types work, but the resonance pot has no effect. Tracing a sine signal through the feedback pathway, I found that it ...
9
votes
4answers
2k views
Good filter design software for Mac OS X/Unix?
I need to implement a simple lowpass filter for a data acquisition circuit (using stretch conductive fabric as a resistive sensor). Various sources have recommended that the best way to go about this ...
2
votes
2answers
2k views
Mains Hum Filter
Are there any chips or simple circuits available for removing the 50/60Hz mains hum from a regular power supply unit?
So I've got a few bits of audio equipment that have bad PSUs and they have a bit ...
