################################################ #Remaining Work ####################### See faraday's AC source graphics Get the time units to work out correctly. o Is the ac current (in a circuit with capacitor) symmetric? o If not, is the asymmetry correct? -When you have an AC voltage source and a light bulb in series and turn the frequency to 10 Hz, it looks like the current drifts slightly (counter clockwise) as it oscillates back and forth. I put the mouse cursor next to one of the blue dots and watched how one particular blue dot moves over time. Every 10 secs or so, the current stutters ever so slightly and shifts the current over. This seems like a very small/minor problem, but I'm not sure if it's effects can be easily seen with a more complicated circuit. -I noticed the same performance issues as Kathy. As soon as there were many components in the play area, things got bogged down. -When I have 2 caps in series with a bulb and battery and turned the voltage up rather high, only one of the caps catches on fire (the one near the battery). See cck_fire.gif. >>Couldn't reproduce this yet. -When you have 2 caps in the play area and you turn one of them 180 degrees around, it looks a little strange next to the other one that has not been turned around--sort of an MC Escher effect. See cck_escher.gif. -There's a slight issues with the capacitors. I charged up two identical capacitor at different voltages (100 V and 10 V) so that there are different amounts of charges on them. Then, I removed the charged caps from their circuits (see cck_caps_separate.gif). I connected the positive side of one cap to the negative side of the other cap. I expected to see the charges on these two connected plates redistribute themselves, but nothing happened. (see cck_caps_together.gif). When you connect the outside plates of this 2 cap combo with some wires, the charges on the plates then properly distribute themselves. >>Yes, this is a real problem I'm not sure is addressed by my circuit analysis. I'm not sure whether my circuit analysis should be giving the right behavior here, or if we'll have to detect it and handle it separately. -On that same note, when I had 2 independent charged capacitors (not attached to anything else) it was sometimes hard to grab them with the cursor and move them. When you click on them, they would not be highlighted in yellow like usual. - Unfortunately performance is an issue ... it's pretty easy to get to the point where the mouse isn't working well and it is frustrating to build anything... is there any hope of improving this (ever)??? - is there any way to make the current graph smoother? Right now it shows features that aren't really there? What should happen to the charge stored on a capacitor while the user is editing the capacitance? - Changing capacitance still doesn't show the right thing ... it doesn't show the electrons flowing again to fill up the plate with more or less charge. >>Yes, I thought it would be awkward to keep the charge constant across the capacitor while editing the capicatance (which would be implemented by manipulating the potential drop to account for the difference). The potential drop is constantly changing, based on other elements in the circuit, and I'm not sure of a good way to account for both of these issues. - I ran across a wierd bug, (see attached). I had a nice looking circuit and when I was trying to add a bulb to it, it was sort of bogging down as I was dragging the bulb, and then all of a sudden it collapsed to one line, as shown and totally changed the components in the circuit (?). Do you have a short cut of keys that I may have pushed? For future: Quantitative graph values. Quantitative CCK can wait until after AAPT - graphs ... would be nice to add dashed grid in background so easier to read where you are, also would be nice to have a cursor which could move around and scroll along graph, this would require a play, pause, step button to be added in bottom of sim. ################################################ #Lower Priority ####################### Help button should be moved south. o Improve the approximation for determining capacitor current. -Could use solution from companion model, but more difficult to code. There is a noticeable delay when dragging a component from the toolbox for the first time; this has confused some users. Bug: capacitor clips are clipping all electrons, not just electrons in that branch of the circuit Explain and remove fudge factor for capacitor in MNASolution? -If you build a simple circuit (battery, resistor, capacitor, and wires in series) and wiggle an element or node back and forth around with the mouse, the blue balls stop flowing from a node 2 or 3 nodes clock-wise from the element or node you are moving around. The blue balls stop flowing through this particular node, but the rest keep on flowing, so you get a wire or element with an absence of blue balls because they all flow out. This may be due to the fact that the wire has to redraw the number of blue balls because wiggling an element or node changes the number of blue balls (according to its length). o Set node voltages from the MNA, then use that to compute voltmeter readouts (instead of complex and error-prone graph theory computation). Quantitative numerical tests for RC, RLC Circuits, etc. -When there were two circuits running in the play area, there was definitely a decrease in performance and things ran a bit slower. If you grab a wire, say, from the tool bar and drag it around in the play area, there is a noticeable lag between the cursor and the wire moving with it.