PCB Electronic Components – How To Identify Electronic Components?
Are you a new electronic hobbyist and want to learn more about PCB electronic components so that you can scrounge for parts and save some bucks? The best place to begin from is to get your hands upon an old electronic gadget but here is a huge problem here – how do you identify parts on the circuit board? Read through the post which shall help you differentiate the various electronic PCB components.
Resistors
The most commonly used electronic component – resistors, are generally color coded through which you can determine the value in ohms. They are marked with R on circuit boards. Some have the values and tolerance printed on them. Checking the resistance from a multimeter is also a great idea, however, you must isolate the resistor from the PCB first or else the soldered resistor will yield inaccurate values.
Inductors
Simply put, an inductor is nothing but a conductive coil of wire which is used to induce inductance in the circuit. They are marked with L on the PCBs. To figure out the exact values of inductors is a bit difficult. You will need to have to good inductance measuring device for mostly the inductors are not color coded like the resistors. In the case of MOSFET, it is advisable to refer to the datasheet for the identification of the gate, source ad drain.
Capacitors
Capacitors are common energy storing PCB electronic components. Generally, they are used to introduce time delays in the circuitry. They are also used in removing noise from filters, remove ripples from the circuit and make the circuit more stable. Typically, they are marked with a C on the PCB. The values of the capacitors are printed on the body. If they are color coded, then you may find out the value from the color code chart of the resistors.
Diodes
PCB electronic components, diodes are marked with a D on the PCBs. Normally 1N4148 is used. These have a voltage drop of 0.7. Rectifiers have part numbers 1N4001 till 1N4007 for amp rating of 1A and 1N5401 till 1N5408 for amp rating of 3A. Other types of diodes are zener, and LED (common colors are red, yellow, green, white and blue). Most of the LEDs have a dome shaped head
Oscillators
Oscillators or crystal are used in electronic devices like radios, transmitters and computer clocks that produce a periodic signal of oscillating nature. On the PCBs, they have a marking of either X or Y. They can easily be identified by examining on sight. Most of the crystals and oscillators are labeled with the operating frequency.
Relays
Relays are switches that are used to open and close electronic circuits. The specifications of the relays are printed on the packaging. These are marked with K on PCBs.
Transistors
Transistors come in two types of packaging: metallic or plastic. The transistor values are printed on the body. From the flat side that faces you, you can count the pin numbers from 1 to 3. So if it is NPN BJT transistor, pins 1, 2 and 3 are collector, base and emitter (CBE) respectively. The pins are reversed in PNP transistors.
Integrated Circuits
Integrated circuits or ICs are marked either with U or IC on the PCB. Most ICs have a similar packaging so it is not really feasible to determine the functionality of the IC by simply looking at it. It could be an amplifier, microcontroller, logic gate or even an A/D converter! To figure out what the IC is meant for, you will have to examine it closely for the logo of the manufacturer and the IC part number so that you can browse the component’s datasheet online.