Sensors & Transducers
Turning the physical world into signals
Temperature Sensor (thermocouple/RTD/IC)
Sensor
A device that measures temperature by converting heat into an electrical signal. Used in environmental monitoring, industrial processes, and consumer electronics.
Humidity Sensor (DHT etc)
Sensor
A sensor that measures the amount of water vapor in the air. Commonly used for weather stations, HVAC systems, and environmental monitoring.
Gas / Air-Quality Sensor (MQ)
Sensor
MQ-series gas sensors use a heated tin-oxide surface whose resistance drops in the presence of target gases. Cheap and sensitive but power-hungry, slow to warm up, and only semi-quantitative without careful calibration.
PIR / Motion Sensor
Sensor
Passive Infrared sensor that detects motion by sensing changes in infrared radiation (heat) from moving objects, primarily people.
Ultrasonic Distance Sensor
Sensor
A sensor that measures distance by sending out ultrasonic sound waves and timing how long they take to reflect back.
Hall-Effect Sensor
Sensor
A chip that senses magnetic fields via the Hall effect. Digital versions switch like a contactless reed switch; linear versions output voltage proportional to field — hiding inside BLDC motors, current sensors and every phone compass.
Accelerometer / Gyro / IMU
Sensor
Accelerometers feel gravity and motion, gyros feel rotation rate; an IMU packages both (often + magnetometer) with an I2C/SPI interface. Sensor fusion turns their noisy, drifting outputs into a usable orientation.
LVDT & Displacement Transducers
Sensor
The Linear Variable Differential Transformer: a movable iron core between one primary and two opposed secondaries turns position into a phase-referenced AC voltage. Frictionless, infinite resolution, and the single most-asked transducer in Instrumentation exams.
Rotary Encoder (Incremental / Absolute)
Sensor
Turns shaft rotation into digital pulses: quadrature A/B channels report every step and its direction. From the ₹30 knob on a 3D-printer panel to the 5000-line optical encoder closing a servo loop — position feedback is encoders.
Current Sensor (Hall / Shunt / CT)
Sensor
Devices that measure electric current by detecting magnetic fields (Hall/CT) or voltage drop across a known resistance (shunt). Essential for power monitoring and control.
Load Cell / Strain Gauge
Sensor
A machined metal beam with strain gauges glued to it: load bends the beam microscopically, unbalancing a Wheatstone bridge by microvolts. An HX711 amplifier turns that into weight readings.