- Asked 2/15
- 2068 Bhadra · 3 marks
- 2067 Mangsir · 6 marks
Short note: Transducer
Short answer
A transducer converts a physical quantity into a proportional electrical signal. It has a sensing element and a transduction element; active types (thermocouple) generate voltage without external power, while passive types (strain gauge, thermistor) change resistance requiring excitation.
Write a short note on transducer.
A transducer is a device that converts one form of energy into another. In instrumentation, it converts a non-electrical physical quantity (temperature, pressure, light, displacement, sound) into a proportional electrical signal (voltage, current or resistance change), or the other way round.
Parts
Physical +----------+ +--------------+
quantity -->| Sensing |---->| Transduction |--> Electrical
| element | | element | signal
+----------+ +--------------+
The sensing element responds to the quantity, and the transduction element converts that response into an electrical signal.
Classification
- Active (self-generating): produce a voltage or current without an external supply. Examples: thermocouple, piezoelectric crystal, photovoltaic cell.
- Passive: need an external power supply; they change R, L or C. Examples: strain gauge, thermistor, LDR, LVDT, potentiometer.
- Input and output transducers: microphone (input), loudspeaker (output).
Examples
| Transducer | Quantity | Output |
|---|---|---|
| Thermocouple | Temperature | Voltage |
| Strain gauge | Strain/force | Resistance change |
| LDR | Light | Resistance change |
| Microphone | Sound | Voltage |
| LVDT | Displacement | AC voltage |
A good transducer is accurate, sensitive and linear, and has a fast response.
✓ Answer checked by Claude Opus 5.5 (high effort)