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68 Threads found on Falstad
try a series resonance input and buffer with a DC biased emitter follower if
falstad's simulator is free, animated and interactive. By reducing the timestep you can use frequencies in the GHz. Its antenna model provides three simultaneous broadcasts on AM frequencies, which you can tune a detector to pick up individually. LTSpice is free and more sophisticated than falstad's. It contains models o
I'm watching your schematic run in falstad's. I guess S1 is the lefthand switch? As far as I can tell, it creates boost converter action. Here are some tips: The leftmost diode is unnecessary. I recommend that you add several scope traces. Look at Ampere waveforms through inductor, switch, righthand diode. Put 1k ohm resistors across diodes. T
Let's take Colpitts oscillator for example. How does the oscillations start? Imagine that we have simple LC circuit. We charge the capacitor with a battery and then disconnect the battery. When we disconnect the battery the oscillations will start. In colpitts oscillator, the tank circuit is always connected to +V. That's the thing that confus
falstad's AC source is ambiguous as to whether it is oriented upside-down or right side up. You can tell by looking closely at the color of its wires. The upper wire appears red (negative) in both your schematics. Therefore the op amp inputs are working properly in regard to inverting or not inverting. Most falstad icons do not indicate the
No, my circuit is constant voltage, not constant current. The input is listed as RMS so it might be a sinewave. The series resistor and input voltage establish the current. A Slight re-arrangement makes it a voltage controlled low side current
With a 4:1 ratio on amplitude, your drawing is not to scale. (120:30 mVpp) With a /5 counter divider you can make the frequency ratio precise. With 5V logic CMOS, you can easily mix the amplitudes down to your desired level with AC coupling as shown (HPF response ) Here is a quick
Does your Android device support Java? If so, then falstad's is an easy-to-use online simulator. It's animated and interactive. Mistakes are easy to spot and correct while the simulation is running.
Hey all, I'm having a real hard time designing a simple on / off switch for an AC audio signal using an N-channel JFET. I've got some schematics (which I haven't breadboarded out yet), but in trying to simulate these ideas in falstad, they never work. The circuit will run for a while and then quit, or occasionally i'll "reverse bias" the JFET, wh
I think Java based can work and some pretty good models can be simulated if you know the transfer function. Analog Circuit Simulator Applet is available in javascript or wrote the js
If you plan 50 Hz frequency, then a 4H primary inductance is reasonable. That is the default value when I place a power transformer in the simulator (falstad's). However as post #2 states, you can make the frequency faster, allowing you to reduce certain parameters for the transformer. [
A free program recommended often here is LTSpice. (Not sure how many parameters you can change in the semiconductor models.) Also see (although the semiconductor models are simplified):
1st cap controls the Q or peaking at LPF breakpoint, smaller increases boost from 7.5dB, bigger flattens it. 2nd and 3rd cap work together as 2nd order LPF, 1st cap also increases rolloff to 3rd order or 18dB per octave. Same in Q or Op Amp, but Op Amp is lower Z out.121584 If you want simulation text for falstad, let me
switching power converter Are you describing a switched-coil converter? See the thread below. Three basic types are discussed: buck, boost, buck-boost. In my posts are links to tutorial simulations. These are interactive and animated, using falstad's Java applet. (Your computer needs to have Java installed.) www.edaboard
I dont think the Wiki design will work. The difference is polarity and phase shift and the Hartley drives the tapped inductor and feedback one leg with the non inverting
LTspice is recommended by several at this forum. It's free. It supports many IC's made by Linear Technology. falstad's simulator is not Spice family, but it's free and easy to use. Its IC's are basic types... logic gates, op amps, PLL, 555, 4017, flip flops.
Something like many other sites or examples 7 seg. decoder voltage current
Brad can also post link to his graph for his demo
falstad's animated simulator supports a tunnel diode, with these circuits in the menu: * I/V curve * LC oscillator * Relaxation oscillator Free to download and use. Or, run it online and choose from the listed circuits. Look in the menu for Misc. Devices > tunnel diode. You need to have Java installed on your compute
Even falstad has a simple free PLL simulation.
You can use any good CMOS logic inverter with good decoupling. 111687 ω=(LC)e-? where C is the series equivalent of C1, C2 and allow for stray and input capacitance of a few pF.
Let me share
You can make a simple experiment with the falstad fourier series applet and visualize the effect of a 2.5 or 5 GHz bandwidth limitation and a 500 MHz sawtooth. This should clarify a basic problem of a hugh frequency sawtooth generator. Then specify your requirements, or better explain what you want to achieve. Any BJT transistor circuits base
What does these diodes do with the transistor? 110400 110401 Why dont you use a sweep signal on circuits using Analog Circuit Simulator under . You can choose any design then modify by adding components and wires
falstad's animated simulator has a memristor model. Free to download and use at: Screenshot of a sample circuit, showing edit window with parameters for the
I would do
there a java based tool called falstad try simulating the circuit with that.
try this
In case a simulation will be informative... Here is a screenshot of the Tesla coil schematic included in falstad's animated circuit The spark consists of several sparks, resulting from resonant actio
You can drive any simulator with a series resistance of choice like 50R and then adjust bias until input is 50% or in other words R in= 50R. For hFE=200, @5V Rb= 9~10k and ditto with the Load. Thus for Rb=9.5k Zin = 50 Ohms and Zout=200 Ohms with same load,
Another method of measuring the real impedance inputs and outputs is to measure the no load and 50%V load resistance. On this device simulator, the impedance turned out to be near 500 Ohms for maximum power transfer with very high gain on small sig. (1mVp) go here and import this (C
See my posts in this thread: They contain links to my simulations of buck, boost, and buckboost converters (laid out in falstad's interactive animated simulator). Scope traces show updated specs on various components. You can observe specs moment to moment. Just hover the mouse over a component, node,
I sometimes get the 'singular matrix' error in falstad's simulator. It is a vague message which might have any number of causes. In a real circuit it would not necessarily prevent operation. I've found I must try numerous tricks to get around this error. * Avoid placing two capacitors in series. Install a resistor in series with one of the ca
falstad's simulator will do what you want, or something like it. Free to download and use at . As you can see, the scope trace depicts the frequency sweep over time, and the inductor's response. (The Henry value does not change unless you apply unusual conditions.) The right-hand lissajous figure indicates phase changes
Here is a memristor circuit included with falstad's simulator (it includes 7 total). The specs window is If you click the link below, it will open the website load the schematic into his sim
Clicking this link will open the website , load my schematic, and run it on your computer. To re-run the simulation, click the Reset button. When you click Export a window opens containing the data file. I do not believe it is in Spice format.
In falstad's simulator I make the AC voltage +- 0.45. I add 1.35 V DC produces a crest at 1.8 V, and a trough at 0.9V (as shown by the scope readouts). I don't know if this will work in your program.
Say, funny you would mention java applets. Check out falstad's simulator. It's animated and interactive. See the Circuits menu for an assortment of seven PLL related circuits. Here's a screenshot of the Type 2
use an NPN transistor (bjt) with a base resistor to invert the logic. something like this --
I made simulations of the schematics. falstad's animated simulator has a spark gap component. I adjusted its parameters to act like a neon bulb. 1) What are the values of R and C (fig.1/fig.2) to that will make a 10sec. flash rate? A neon bulb typically has a 220k resistor in series when connected to house current. So I used
What helped me to grasp the principles of switched-coil converters was an animated, interactive simulator. Below is a link to my conceptualization of a simple buck-boost. Click it to open the website, load my schematic, and run it on your computer. (Click Allow to load the Java applet.) Watch th
It might help to watch an interactive simulation of an SR flip flop in its simplest form. The link below is to a SR flip-flop made from 2 transistors. It will open the website, load the schematic and run it on your computer. (Click Allow to load the Java applet.) Click the two logic inputs at the
There is an interactive animated simulator that will help to aid in understanding. Its library of circuits includes the multivibrators you mention. Click the link below. It will open the website at . It will load a monostable multivibrator constructed from transistors, and will run it on your computer. (Click Allow to lo
falstad's animated simulator does not specifically list a D flip-flop made from discrete components. It provides a link (below) which will open a simulation of a CMOS flip flop made from discrete mosfets. It will run interactively on your computer. (Click Allow to load the Java applet.) Click the logic inputs which are labeled S and R. Watch
I guess it's all right to show you the layout that works for me, since it started with your I made this using an animated simulator found (free) at: The op amps need the right vo
falstad's animated simulator is ideal for observing the action. It turns wires green when they are positive polarity, gray when they are neutral. Its library of circuits comes with a D flip flop made from individual gates. It's just a matter of drawing a wire from the Not-Q output to the D input. Click the link below to open the we
Have you tried playing with a simulation? Here is my screenshot using falstad's animated simulator. It is great for showing immediate results when you adjust I find that the biasing is tricky to get ri
I find falstad's animated simulator easy to use. It's free. It's interactive. It shows current bundles moving through wires, and portraying the interaction between components. It comes with a library of circuits. You can construct your own circuits. You can save them to disk and read them again. This link will open
I had to spend hours playing with an animated simulator (falstad's), before I got a notion what is happening in these switched coil converters. Is it possible to write enough equations to correctly solve for everything simultaneously or do I need to select a particular parameter as a starting point are work outwards from there? Th