iCircuit recently appeared on Apple’s App Store, offering a basic schematic editor, plus circuit simulator with multimeter, and oscilloscope views. Per the app’s description -
There are over 30 elements you can use to build your circuits. The app has everything from simple resistors, to switches, to MOSFETS, to digital gates.
The app features a multimeter that you use to probe around the circuit to instantly read voltages and currents. If you want to see how a value changes over time, then you can add values to the built-in oscilloscope. The scope can simultaneously track many signals over time and features a touch interface to control the total time displayed and stacked and unstacked modes to easily compare signals.
Supported elements include:
- Signal generators, Voltage sources, and Current sources
- Resistors, Capacitors, and inductors
- Manual SPST/SPDT Switches, and SPST/SPDT relays
- Diodes, BJ Transistors, and MOSFETs
- Speakers, Buzzers, and LEDs
- ADCs, and DACs
- Logic gates: AND, OR, NAND, NOR, XOR
- JK and D Flip-flops
I gave the app a quick spin on the iPad, and it definitely shows a lot of potential. The simulator had a tendency to lag a bit behind my realtime changes to the schematic, and the UI took some getting used to, but for $10 it sure beats the mobile simulator competition (which is pretty much nonexistent, to my knowledge).
In any case – a handy tool to have around when away from the lab. As the developer notes, the software is rather CPU-intensive so newer devices are recommended (iPhone 3GS or later). iCircuit on iTunes
For a very similar Java applet, check out Paul Falstad’s Circuit Simulator Applet.