Bridge Drives a Decision - Electronic Circuits II & III: Decision Networks and Interfaces Step by Step

A bridge output can feed a threshold decision, turning a measured voltage difference into an on/off state for a later circuit. This page treats the 2 V bridge signal and 1 V threshold as exact training numbers; real comparators need noise margin, hysteresis, propagation delay, input offset, and measurement tolerance.

An ideal threshold switch follows the computed bridge voltage, not a hand-authored label. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Use the computed bridge voltage

The unbalanced bridge gives 2 volts.

V_{\text{bridge}} = 2\ \text{V}

The threshold decision follows the voltage

The bridge voltage is above the 1 volt threshold, so the ideal switch state is derived as on. Noise margins, hysteresis, and propagation delay are deferred.

2\ \text{V} > 1\ \text{V}