Controlled Switches

Control Threshold

below stays open, above closes

The helper derives switch state from exact control and threshold voltages before it computes current. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Below threshold leaves no load current

The lower control is 2 volts, below the threshold, so the load current is 0 amperes.

2 V<3 V2\ \text{V} < 3\ \text{V}
Below thresholdThe switch is open and the load path is broken.12 Vopen4 ohmA0 Acontroloffload

Above threshold closes the load path

The higher control is 5 volts, above the same threshold, so the load current becomes 3 amperes.

5 V>3 V⇒I=3 A5\ \text{V} > 3\ \text{V}\Rightarrow I = 3\ \text{A}
Above thresholdThe switch is closed and the load current is checked.12 Vclosed4 ohmA3 A3 A+-12 Vcontrolonload