Understanding Transistors and Their Functions

Transistor is a semiconductor electronic component that has 3 electrodes, namely Base (Base), Collector (Gatherer) and Emitter (Emitter). This component serves as an amplifier, breaker and connector (switching), voltage stabilization, signal modulation and many other functions. In addition, transistors can also be used as electric faucets so that they can conduct electricity very accurately and as a source of electricity.

Transistor actually comes from the word “transfer” which means transfer and “resistor” which means resistor. From these two words we can conclude, the meaning of a transistor is the transfer or transition of a semi-conducting material to a certain temperature. The transistor was first invented in 1948 by William Shockley, John Barden and WH, Brattain. However, this component began to be used in 1958. Transistor types are divided into 2, namely PNP transistors and NPN transistors.

Transistors are generally made of semiconductor materials such as Germanium, Silicon, and Gallium Arsenide. In general, transistors can be divided into 2 types, namely Bipolar Transistor (BJT) and Field Effect Transistor (FET).

Transistor Function

Transistor functions include:

  • As Amplifier Amplifier,
  • As a rectifier,
  • As a voltage and power amplifier,
  • As a voltage stabilizer,
  • As Mixer,
  • As an Oscillator
  • As a Switch (Circuit Breaker and Connector),
  • As generator of low or high frequency.

Transistor Basic Structure

Basically, a transistor is an electronic component consisting of 3 layers of semiconductors and has 3 terminals, namely the emitter terminal which is abbreviated to the letter “E”, the base terminal is abbreviated to the letter “B” and the collector terminal is abbreviated to the collector. with the letter “C”. Based on its structure, the transistor is actually a combination of 2 diode junctions. From this combination, transistors are then divided into 2 types, namely NPN type transistors and PNP type transistors which are also called Bipolar Transistors. Bipolar is said because it has 2 polarities in carrying electric current.

NPN stands for (Negative-Positive-Negative) while PNP stands for (Positive-Negative-Positive).

The following is a picture of the type of transistor based on the semiconductor layer that forms it along with the symbols for the NPN and PNP transistors.

NPN and PNP . Transistors

How to Measure Transistor

We can use an Analog Multimeter or Digital Multimeter to measure or test whether a transistor is still in good condition. It should be reminded that there are differences in the Polarity (Red and Black) layout of the Analog Multimeter and Digital Multimeter Probe in measuring/testing a Transistor.

The following is a way to test or measure transistors using an analog multimeter and a digital multimeter.

Read also:

A. Measuring Transistors with an Analog Multimeter

Measuring Transistors with an Analog Multimeter

How to Measure a PNP Transistor with an Analog Multimeter

  1. Set Switch Position at OHM Position (Ω) x1k or x10k
  2. Connect the Red Probe to the Base Terminal (B) and the Black Probe to the Emitter Terminal (E), if the needle moves to the right showing a certain value, it means the transistor is in good condition.
  3. Move the Black Probe to the Collector Terminal (C), if the needle moves to the right showing a certain value, it means the transistor is in good condition.

How to Measure an NPN Transistor with an Analog Multimeter

  1. Set Switch Position at OHM Position (Ω) x1k or x10k
  2. Connect the Black Probe to the Base Terminal (B) and the Red Probe to the Emitter Terminal (E), if the needle moves to the right showing a certain value, it means the transistor is in good condition
  3. Move the Red Probe to the Collector Terminal (C), if the needle moves to the right showing a certain value, it means the transistor is in good condition.

Notes :
If the Probe Layout is reversed from the method mentioned above, then the Needle on the Analog Multimeter must not move at all or “Open”.

B. Measuring Transistors with a Digital Multimeter

In general, Digital Multimeters have the function of measuring Diodes and Resistance (Ohms) in the same Switch. So for this type of Digital Multimeter, Multimeter Testing is the reverse of How to Test Transistors Using Analog Multimeters.

Measuring Transistors with a Digital Multimeter

How to Measure a PNP Transistor with a Digital Multimeter

  1. Set the Switch Position on the Diode Position
  2. Connect the Black Probe to the Base Terminal (B) and the Red Probe to the Emitter Terminal (E), If the Multimeter Display shows a certain Voltage value, it means the Transistor is in good condition
  3. Move the Red Probe to the Collector Terminal (C), if the Multimeter Display a certain Voltage value, it means the transistor is in good condition.

How to Measure an NPN Transistor with a Digital Multimeter

  1. Set the Switch Position on the Diode Position
  2. Connect the Red Probe to the Base Terminal (B) and the Black Probe to the Emitter Terminal (E), If the Multimeter Display shows a certain Voltage value, it means the Transistor is in good condition
  3. Move the Black Probe to the Collector Terminal (C), if the Multimeter Display shows a certain Voltage value, it means the transistor is in good condition.

Notes :
If the Probe Layout is reversed from the above mentioned method, the Digital Multimeter Display must not show Voltage Value or “Open”

Thus a brief explanation of the meaning of transistors and their functions, hopefully the article above can be useful and beneficial for all of you.