Electronics Engineering Lab

List of Experiments / Activities

1. 1Unit I — Diode Characteristics and Bridge Rectifier — Plot V-I characteristic of a silicon diode; set up a full-wave bridge rectifier with filter capacitor; measure DC output. Application: DC supply for a portable pH meter or field soil sensor unit.
2. 2Unit I — Zener Diode Voltage Regulator — Set up Zener regulator; vary supply voltage and load; measure regulated output. Application: regulated 5V supply for an Arduino-based irrigation controller or biomedical instrument.
3. 3Unit I — LED and Photodiode Characteristics — Measure LED forward voltage and current at different current levels; observe LED brightness; measure photodiode reverse current vs. illumination. Application: LED indicator in diagnostic equipment; photodiode in pulse oximeter (SpO2) light detection.
4. 4Unit II — BJT as a Switch – Relay Driver for Solenoid Valve — Use NPN BJT to switch a relay; connect relay to control a solenoid valve (or motor) ON/OFF using a small control signal. Application: automated irrigation valve control triggered by a soil moisture sensor reading.
5. 5Unit III — Thermistor Sensor Calibration — Measure resistance of a thermistor at different temperatures (room to 80°C); plot R-T curve; convert to temperature using calibration equation. Application: temperature monitoring in fermenters, incubators, and cold storage for agri-produce.
6. 6Unit III — Op-Amp Signal Amplifier for Sensor Output — Connect thermistor (in bridge) to non-inverting op-amp amplifier (IC 741); measure amplified output voltage for different temperatures. Application: amplifying the tiny output of a biosensor or thermocouple for display or ADC input.
7. 7Unit III — Op-Amp Comparator – Temperature or Light Alarm — Set up op-amp comparator with sensor input and adjustable reference; drive an LED or buzzer when threshold is crossed. Application: over-temperature alarm in biomedical autoclave; under-light alarm in greenhouse; frost alarm in farm.
8. 8Unit III — Soil Moisture Sensor – Calibration and Signal Conditioning — Measure output voltage of a capacitive or resistive soil moisture sensor at dry, moist, and saturated soil conditions; amplify output with op-amp if needed. Application: drip irrigation automation — turn pump ON when soil moisture drops below threshold.
9. 9Unit IV — Logic Gate Truth Table Verification — Verify AND, OR, NOT, NAND gate truth tables using a logic trainer; implement simple control logic: Pump ON = Soil_Dry AND (NOT Tank_Empty). Application: basic automated irrigation logic; digital control in biomedical instrument.
10. 10Unit V — Solar Cell – I-V Curve and Battery Charging Circuit — Plot I-V curve of a small solar cell; connect to a 12V battery via a simple charge controller; measure charging current. Application: solar-powered soil sensor node; off-grid poultry farm lighting; portable biomedical device charging in rural areas.
11. 11Unit V — IoT Soil / Environment Sensor Node (Arduino/NodeMCU) — Connect soil moisture and temperature sensors to an Arduino/NodeMCU; read sensor values on serial monitor; display on LCD; (if Wi-Fi) send data to ThingSpeak/Blynk. Application: precision irrigation monitoring; smart greenhouse; remote biomedical patient environment monitoring.
12. 12Unit V — Pulse Oximeter / Heart Rate Sensor Demo (Biomedical) — Connect an IR + red LED pulse sensor (MAX30100 or similar) to an Arduino; display SpO2 and heart rate on serial monitor or LCD. Application: understanding the electronics inside a clinical