Electronics 4
Act 4
Act 4
- Sensors
- Breadboard
- Transistor
There are 3 types of sensors used in D&T.
- LDR: Light Dependent Resistor Use in light sensing circuit
- Thermistor Use in temperature sensing circuit
- Moisture Sensor.: Used in moisture sensing circuit
LDR. how it works
- LDR is a light dependent resistor where its resistance varies with the amount of light it received.
- Due to this property, it is used in a light sensing circuit.
Questions
- List the types of sensors used to detect light.
How to use a breadboard.
Transistor
Transistor
- A Transistor is an electronic component that acts as a switch or amplifier.
- It comes in a package with three terminals.
- There arte 2 types of Transistor NPN or PNP.
- NPN are commonly used in our syllabus. In D&T we are only interested to see NPN transistor as an electronic switch.
- For a NPN transistor, it consist of 3 terminals. Collector, Emitter and Base.
- Click here to see how a transistor works as a switch.
- A small current flowing to the base of the transistor to emitter will cause the transistor to switch on.
- When the transistor is switched on, larger current will then be able to flow from collector to emitter.
- A transistor works by controlling the current going to base hence switching the transistor on or off. unlike a physical switch, a transistor can only be turn on or off by electrical means.