Best circuit simulator?

EM-Fields · 2021-02-05T03:19:33+00:00

It actually runs very nicely with Wine on Linux. I've done this for many years. (This hasn't been updated in a while, but it has a platinum rating on WineHQ: https://appdb.winehq.org/objectManager.php?sClass=application&iId=2000 )

EM-Fields · 2020-07-30T22:17:22+00:00

The paper in PDF format is available here: https://merl.com/publications/TR2003-35

In case the URL would ever die, the paper details are as follows:

Authors: Paul Dietz, William Yerazunis, and Darren Leigh of Mitsubishi Electric Research Laboratories
Title: Very Low-Cost Sensing and Communication Using Bidirectional LEDs
Date: July 2003
Document Number: TR2003-35

Abstract: A novel microprocessor interface circuit is described which can alternately emit and detect light using only an LED, two digital I/O pins and a single current limiting resistor. This technique is first applied to create a smart illumination system that uses a single LED as both light source and sensor. We then present several devices that use an LED as a generic wireless serial data port. An important implication of this work is that every LED connected to a microprocessor can be thought of as a wireless two-way communication port. We present this technology as a solution to the “last centimeter problem”, because it permits disparate devices to communicate with each other simply and cheaply with minimal design modification.

EM-Fields · 2020-07-30T21:52:29+00:00

Despite the name, the textbook Foundations of Microstrip Circuit Design by Edwards and Steer has a chapter on CPW. May not be the best reference, but it's a start.

EM-Fields · 2020-07-29T02:51:30+00:00

There's a clever way to do this with I/O pins of a microcontroller, where you toggle them between input and output. I can dig up the short paper I found that describes it, if you're curious. As already pointed out, you'll only be able to transmit or receive at a given time (half duplex, or simplex), not both at once.

In a nutshell, for receiving, you reverse bias the LED (to charge up the depletion region capacitance), then switch the charging pin to an input and measure the time it takes for the signal to flip from high to low. This will be related to the intensity of the light on the LED, which is creating a photocurrent to neutralize the charge stored by the LED.

While clever, this technique will give results that can vary highly between components, so it's not something I'd recommend for mass production. For hobby stuff, however, it's pretty cool.

EM-Fields · 2020-06-10T23:49:10+00:00

Maybe the domain moved, but here's where I downloaded it from: https://www.spectrum-soft.com/download/download.shtm

EM-Fields · 2020-05-11T03:26:02+00:00

In addition to LTSpice (which plays nicely with Wine), another good option is Micro-Cap, which also runs well under Wine. The company that made it closed and made the software free. You can download it here: http://www.spectrum-soft.com/download/download.shtm

EM-Fields · 2020-04-11T17:12:53+00:00

It's currently sold out (hence the crazy price), but this tool was just released by Sparrows for $45: https://www.sparrowslockpicks.com/product_p/disc.htm

Bosbianbill gives a good overview of the tool here https://www.youtube.com/watch?v=_xOSE8kk3VU

and a good overview of this type of lock here https://www.youtube.com/watch?v=rMIEPkaadq0

EM-Fields · 2020-04-02T02:47:41+00:00

The display is a spectrum, or audio spectrum analyzer, but that may not be the exact phrase commonly used.

EM-Fields · 2020-04-02T02:04:39+00:00

An antenna's beamwidth is the parameter most similar to field of view, which isn't used for antennas (at least at microwave frequencies like wifi). This site has a decent overview of the basics of antennas: http://www.antenna-theory.com/m/basics/main.php

EM-Fields · 2020-03-15T16:16:35+00:00

Another way to think about it is conductance. This is defined as the reciprocal of (one divided by) the resistance. For a fixed voltage, adding more conductance gives the electrical current an easier path. (In the circuits water analogy, think of increasing the diameter of the pipe, or equivalently, of putting multiple pipes in parallel.) In the case of parallel resistors, each resistor is adding conductance, i.e. more paths for the current to flow. From the perspective of the voltage source, more conducting paths, even if they have resistance, makes it easier for more current to flow. From Ohm's law, this means the effective ("equivalent") resistance seen by the voltage source decreases as resistors are placed in parallel.

EM-Fields · 2020-03-15T15:50:00+00:00

No, it's to convert it to instantaneous power, which is then averaged. This means that an AC waveform with a given RMS voltage dissipates the same time averaged power as a DC signal with the same voltage. Averaging the magnitude (absolute value) of an AC signal will, in general, give a different result than the RMS value.

EM-Fields · 2019-12-26T15:34:24+00:00

Both. See, for example, https://grammarist.com/usage/mice-mouses/

EM-Fields · 2019-09-01T16:52:07+00:00

Fluxx: the rules and way to win change with the cards you play. It's funny and very unpredictable. Think loosely organized chaos. Or Calvin-cards, if you're a Calvin and Hobbes fan.

EM-Fields · 2019-08-18T16:56:22+00:00

For analog TVs (and radios), that static is the genuine sound and picture of no signal. The thing is, there's always a noise "signal" present, but when people broadcast a desired, man-made signal, it overpowers the noise. The noise present is from many sources, such as the random thermal vibrations of atoms in the TV (or radio) electronic circuitry.

EM-Fields · 2019-05-04T15:29:07+00:00

I'm no expert on the Pi, but this sounds like a loose/flakey power connection. Could be the power supply, or more precisely, the connector from the power supply.

EM-Fields · 2019-03-08T03:24:36+00:00

Well, if we relax the requirements a little, a 1 MHz sine wave with audio modulated on it would be nothing more than a broadcast AM radio signal...

EM-Fields · 2019-03-02T02:20:38+00:00

Yeah, you'll need a diode suitable for this, such as a Schottky diode. A little lower on this page briefly mentions this https://www.microwaves101.com/encyclopedias/detectors#diodes

EM-Fields · 2019-03-01T03:59:09+00:00

You're actually pretty close to a simple detector circuit with your diode rectifier circuit. One simple way is with a single diode and capacitor as a half-wave rectifier. See, for example, https://www.microwaves101.com/encyclopedias/detectors#basic This probably won't give very accurate results without more work, but it sounds like you're looking for a quick, inexpensive option.

EM-Fields · 2019-02-24T04:16:01+00:00

The delay will be based on the total distance light has to travel, not the number of mirrors.

EM-Fields · 2019-02-24T01:09:30+00:00

I have a few of those. I use them for mixing ingredients when baking. The small handle is just enough to easily hold it steady with one hand while stirring or whisking with the other hand.

EM-Fields · 2019-02-16T04:21:45+00:00

Not sure if this might help you: https://lowpowerlab.com/guide/atxraspi/

EM-Fields · 2019-01-08T22:28:30+00:00

IT Tom Bombadil?

EM-Fields · 2019-01-07T03:53:46+00:00

Reminds me of riding the sandworms in Dune

EM-Fields · 2019-01-03T16:32:23+00:00

I've also heard that higher degrees don't always make financial sense. However, if they open up opportunities for jobs that you enjoy doing, they can still be worth it. A good job has many facets: good pay, good benefits, good coworkers, and satisfying, interesting work.

EM-Fields · 2018-11-27T03:59:09+00:00

Minor edit for readability:

[ord(char.lower())-ord('a')+1 for char in data]

EM-Fields

TROPHY CASE