Физика

The Zener diode as a voltage stabiliser

Light-emitting diodes

Photo diodes

Solar cells

NPN and PNP transistors

The transistor as a switch

Principle

A transistors is used to work as a switch in an electronic circuit.

Tasks

Observation of:

• collector current
• collector-emitter voltage
• base-emitter voltage
• base current

Benefits

Easy to use set-up on a plug-in board.

The transistor time-delay switch

Principle

A transistor circuit is used to demonstrate time controlled delay switch.

Tasks

Investigate the factors responsible for delaying switching of a transistor.

Benefits

Easy to handle plug-in board

Transistors as voltage amplifiers

Characteristic curves of an NPN transistor

Stabilisation of the operating point

Temperature control of a transistor

Undamped electromagnetic oscillations

The simple electrical circuit

Principle

The students should first perceive that an electric current can only flow in a closed circuit. To achieve this, the simplest possible circuit is used, in which there is neither a series or parallel connection, and which is therefore called the simple circuit.

The students ...

Measurement of voltage

Measurement of current

Principle

A simple circuit is examined to introduce the measurement of the strength of an electric current. It is assumed that the students understand the term current and its unit.

When they know that electric current is defined as the number of freely moving electrons which pass a ...