Short Circuit

The leds in this app are configured at 2v and 20ma. By using Ohms Law the current limiting resistor would be 9v-2v=7v÷20ma=350ohms for the current limiting resistor value.

Do not use this circuit to protect anything in real life! Ever! First off, it is not clear where the output is supposed to be, but even if you assume that the output is across the LEDs and resistor (either LED) and you short it out, the circuit will not shut off power at all, it will just spark at first, and then melt the wire/contact and/or kill the battery; whichever comes first. The only thing that the push button does is energize the relay…. I know it looks like it’s simulating a short, but not really, however; if it’s a handmade relay and it’s not properly designed for the battery, or if it is designed for a higher battery voltage than what your using, or you are simply using the wrong relay or if the battery voltage is nearly dead than it could definitely cause issues by drawing too much current, which would also be just as bad!

The basic idea behind a real short circuit protection circuit, is that it will sense how much current is being drawn by the load, and automatically switch off all current to it, if exceeds a certain value…. Some will completely switch off and stay off until you reset it (kinda like a breaker panel) and others will simply adjust the output voltage proportional to how much current is being drawn by the load and it will “limit” the current, or regulate it in other words. And then there’s the simplest of all that is non-reusable that most everyone is familiar with: AKA, the Fuse.

Here’s a simple example I just made of a current limiter: http://everycircuit.com/circuit/4965228720422912

Looks like it might be an incorrectly wired attempt at a diy circuit breaker where when the current passing through the relay coil is enough to trigger it it switches off the circuit it's powering but it should be wired something similar to https://everycircuit.com/circuit/5588891173912576

Yeah that’s kinda what I suspected the original idea was too