How do I delete circuits?
Circuits are deleted by first moving them to the Trash and then by emptying the Trash.
To move a circuit to the Trash, you change its folder to "Trash". Click on the circuit config button (looks like a gear), and then change its folder to "Trash".
The next time you are browsing files and navigate into the Trash, you will be able to empty it.
How do I delete elements?
Select the element and use the Editor to delete the element. If you have multiple elements selected, then all of those elements will be deleted.
To open the element editor on the iPad, select an element and make sure that the Editor pad (upper right) is expanded by single-tapping its title.
On the iPhone and iPod Touch, double-tap an element and the editor will appear.
Why do relays act differently when I have ground elements and when I don't?
Lots of elements in the application need to compare voltages to ground to determine their output. This is common in digital logic elements, but is also done in, for example, the control input of relays. Circuits would become a mess if every element was required to show its ground connections. To save space, some elements have intrinsic connections to ground.
When there is no explicit ground element in the circuit, that circuit is said to be floating and a random node is chosen to be ground.
If you have a floating circuit, then you are not in control of what the simulator is choosing to designate as ground. The simulator is intelligent and will try to pick a node that "looks like" ground, but you are really just gambling.
When you add an explicit ground element, the simulator now has an absolute reference. You should then make sure that your circuit is attached to this ground, otherwise the remaining floating elements will be compared to the absolute ground and random results will ensue.