Electronics / Circuit design · 2026

Analog window comparator

Turning a temperature threshold into a working analog control circuit.

CONTRIBUTION

Circuit synthesis, simulation, and bench testing

STAGE

Coursework · Electronics prototype

TOOLS & METHODS

LM358 · NI Multisim · Bench testing

01 / CONTEXT

The challenge.

A temperature control circuit needs to distinguish an acceptable operating range from conditions above or below its thresholds.

02 / PROCESS

Design a dual-threshold window comparator using LM358 op-amps and a 2N3904 driver.
Simulate reference levels of 2.08 V and 1.25 V, giving a 0.83 V operating window, in NI Multisim.
Build a breadboard prototype with an NTC thermistor, relay, and buzzer, then compare DMM readings with simulation.

03 / REFLECTION

Bench reference measurements were reported within 3.85% of simulation under saturated switching.

Analog electronics coursework using an LM358 comparator and a transistor-driven relay output.