List of electronic component basic properties

Electronic components all have properties that can be taken advantage of to do something useful or at least interesting. This page will be devoted to briefly listing common properties of particular components that are commonly used or studied.

Common individual components:


2 terminals. Usually a very poor conductor of electricity (current). The poorer it’s conductance, the higher it’s resistance rating in units called Ohms.

  • Unit – Ohms
  • Tolerance – Possible percentage greater or lower difference actual component may differ from rated value.
  • Power rating – Wattage rating for maximum heat dissipation in units called watts (most common resistors are 1/4W).


2 terminals. Conducts current at relatively low voltage while forward biased and blocks a relatively large amount of voltage while reverse biased. Actual values depend on the type of diode being used and it’s part number when applicable.

  • Forward biased –
  • Reverse biased –

Capacitor: Stores energy in an electric field between separated conductive areas (plates).

  • Unit – Farad (F). Super/ultra capacitors about 1F or more while regular capacitors are rated in the micro, nano and pico farads.


Bipolar Junction Transistors (BJTs)

3 terminals (collector, base, and emitter). A smaller voltage/current (signal), from base to emitter, controls a larger amount of voltage/current flow (amplification) from collector to emitter.

NPN: Collector is wired up to be more positive than emitter and is always a part of the load path. The transistor is normally off. But, if the base exceeds about 0.6V above emitter, then current will start flowing from base to emitter. Due to that base current, a multiple amount (based on the transistor’s gain and factors influencing it) of current is allowed to pass from collector to emitter.


Common integrated circuits:

555 timer:

Outputs either a high or low signal that is strong enough to power small loads. Typically wired in one of 3 modes, flip flop, monostable mode (one shot timer), or astable mode (continuously changing output). All that is needed to control timing speed is a capacitor and at least 1 resistor.

Operational amplifier (Op amp):

Output voltage/current is determined by comparing the voltages at the non-inverting input and inverting input.

Common power sources

Bench power supply:

Breadboard power supply:


FET Transistors


  • High input impedance – voltage controls conduction. Not current.

More to come!

Links that support this site

Become a Patron!

Home page