Images How do you draw circuits? Circuit diagrams are amongst the most abstract representations used in elementary physics teaching. How best to support reasoning with them, and indeed, what kinds of reasoning do you want to support? Or, more succinctly, how do you prepare to answer the question "Why are we doing this, miss?" Diagrams play a significant supporting role in reasoning about circuit loops, so starting with thinking about choices made, even after deciding to use conventional symbols, may be productive.
So a coffee-break sketch suggests that 2.5 D model of a series of hinged ramps floating over a circuit diagram could be built....where the change in height of the ramps is set by the pd. But not by me, because all of the controls and circuit elements are in 2D, and would have to be re-engineered for 3 D. Plus a whole heap of Cartesian geometry to relate the hinged ramps to changes in the pd. I’ll stick with the physicality of reasoning with ropes and the interactive diagrams already developed for that approach in Supporting Physics Teaching.
Supporting Physics Teaching did not make so much of up and down hill models, or even colouring in circuits, although both were there and discussed. That’s perhaps because I was not such a fan. I like something that’s both tangible and manipulable, so you and the children can fiddle with it, to make predictions. Hence the investment in rope loops. What do others think? Maybe there is a cunning interactive diagram waiting to be drawn that allows the ramps to be manipulated: at the very minimum, they’d have to be flattened when the circuit was broken. I did see a simulation of the transient states of a circuit back in 1998 which did some of this, but then failed to relocate it, even after I’d remembered the author...
With circuits I have become a big fan of the various ramp models. I think they make understanding PD relatively easy. Hence, I would like to see a way of drawing circuits that feeds into that, where it looks like something is going to go down the ramp. Some of the simulations do this (https://www.youtube.com/watch?v=m4jzgqZu-4s) but my attempts to draw it on paper were rubbish. Maybe it's not possible or desirable to take a 2D representation and add a 3D component. Tony Reeves wrote about using colour for this (https://iopscience.iop.org/article/10.1088/0031-9120/38/3/401) and while that approach has many positives it doesn't easily convey the idea of a ramp.
One of the reasons I like the ramp model is that when viewed from above it can just be seen as the rope loop model with no heights involved.
Maybe the solution is to just stay with a normal circuit diagram but add more voltages to the diagram so it becomes more obvious where the ramp like features are?
So a coffee-break sketch suggests that 2.5 D model of a series of hinged ramps floating over a circuit diagram could be built....where the change in height of the ramps is set by the pd. But not by me, because all of the controls and circuit elements are in 2D, and would have to be re-engineered for 3 D. Plus a whole heap of Cartesian geometry to relate the hinged ramps to changes in the pd. I’ll stick with the physicality of reasoning with ropes and the interactive diagrams already developed for that approach in Supporting Physics Teaching.
Supporting Physics Teaching did not make so much of up and down hill models, or even colouring in circuits, although both were there and discussed. That’s perhaps because I was not such a fan. I like something that’s both tangible and manipulable, so you and the children can fiddle with it, to make predictions. Hence the investment in rope loops. What do others think? Maybe there is a cunning interactive diagram waiting to be drawn that allows the ramps to be manipulated: at the very minimum, they’d have to be flattened when the circuit was broken. I did see a simulation of the transient states of a circuit back in 1998 which did some of this, but then failed to relocate it, even after I’d remembered the author...
With circuits I have become a big fan of the various ramp models. I think they make understanding PD relatively easy. Hence, I would like to see a way of drawing circuits that feeds into that, where it looks like something is going to go down the ramp. Some of the simulations do this (https://www.youtube.com/watch?v=m4jzgqZu-4s) but my attempts to draw it on paper were rubbish. Maybe it's not possible or desirable to take a 2D representation and add a 3D component. Tony Reeves wrote about using colour for this (https://iopscience.iop.org/article/10.1088/0031-9120/38/3/401) and while that approach has many positives it doesn't easily convey the idea of a ramp.
One of the reasons I like the ramp model is that when viewed from above it can just be seen as the rope loop model with no heights involved.
Maybe the solution is to just stay with a normal circuit diagram but add more voltages to the diagram so it becomes more obvious where the ramp like features are?