Basic Electronics: Part 1 - Active and Passive Devices

Active Devices:

1. They require external source for their operation.

2. Eg: diode, transistor, zener etc

3. These devices are not capable of amplifying or processing electrical signals.

4. They are the devices which produce energy in the form of voltage or current.(Energy donor)

5. They are nonlinear.

6. Two types: tube devices and semiconductor devices

Tube Devices: vaccum tube, vaccum diode, vaccum triode and gas tubes.

Semiconductor devices: Diode, Bipolar junction transistor, Field effect transistor , SCRs etc.( More used because of its advantages over tube devices)

Explanation: When the diode is connected to the supply, it will not start directly to work until some minimum supply voltage is reached. So diode is termed as active. (details of diode discussed soon)

Thus we get to know that diode requires external source for its operation to deliver the energy in terms of current

Passive Devices:

1. They do not require external source for their operation.

2. Eg: Resistors, capacitors, inductors

3. This devices stores or maintain energy in the form of voltage or current.(Energy Acceptor)

4. Capacitor: stores energy by the virtue of voltage existing across it,
inductor: stores energy by the virtue of current passing through it,
Resistors; decipates energy.

5. They are linear.

6. Two types: One which stores energy, and one which dissipates it.

Explanation: when a resistor is connected to the supply, it directly starts working.