Automotive sensors

Explore how electrical sensors detect changes in the environment and translate those changes into analog voltage or digital signals, enabling measurements of pressure, temperature, position, acceleration, and traffic speed.

Explore passive and active sensors, illustrating how passive sensors require external power while active sensors operate independently, then distinguish signals as analog or digital by their information conveyance.

Explore ultrasonic proximity sensors that use a 40 kHz pulse to measure distance from two centimeters to four meters, with a transmitter and receiver producing an output proportional to distance.

Identify motion sensors that detect movement with infrared light to auto-activate lights. Understand speed sensors measure rotational speed to report vehicle speed and RPM for ABS and ESP.

Explore how thermal sensors measure temperature for environmental compliance and humidity sensing in automated air conditioner units, and their use in engine coolant and air temperature sensing with dashboard signals.

Explore flow and pressure sensors, focusing on air flow sensors that measure volume or mass of air entering the engine, and feed the PCM to optimize the air‑fuel ratio.

Convert pressure into an electrical signal to quantify tire air pressure, using pressure transmitters that output 4–20 mA or 0–5 V, employing the piezoelectric effect and calibration for accurate readings.

The oxygen sensor, located in the exhaust, measures oxygen levels to help PCM maintain the optimal air-to-fuel ratio for emissions control, with a failing sensor triggering the check engine light.

Explore how a knock sensor detects engine knock and signals the ECU to adjust ignition timing. Identify common causes like improper timing, air-fuel ratio, deposits, and spark plug issues.

Potentiometers, also called resistive position sensors, are passive linear or rotary transducers that convert accelerator pedal position into a proportional voltage via voltage divider or rheostat.