I have a basic understanding of electrical things myself, but semiconductors are not part of it. While pondering about some unrelated things, I came up with this question:
Suppose I want to make an electrical constructor toy for kids. There would be some lamps, switches, relays, magnets, wires, etc. And then there would also be a battery that powers it all (something like 9V or 3V, so no electrical danger exists).
Kids being kids, they will make lots of mistakes when building their circuits, and that's good - they learn. But short circuits can destroy the batteries pretty quickly, and possibly even heat something up enough to cause actual damage. It would be nice if that could be avoided, while still giving feedback that there is a short circuit.
So, is it possible to make such a "battery adapter", which would:
- Light a green LED when a circuit is connected and functioning properly (there is some significant resistance in the circuit). Note that this should affect the current/voltage of the circuit as little as possible.
- Light a red LED when there is a short circuit (very low resistance of the circuit), while also severely limiting the current flowing through the circuit (so nothing gets destroyed). When the short circuit is resolved, the LED should go off and the current limit be removed.
For bonus points, a yellow LED could light up when two power supplies are chained together, doubling the voltage of the circuit. This is can be used in some educational experiments (like seeing that a lamp suddenly lights up twice as bright), however it also shortens the lifespan of some circuit elements, so there should be a warning. However I do not know if this can be reliably detected from within the adapter itself (without some extremely fancy communications between adapters).
Is this plausible? Can anyone show me a schematic of such a device?