Thermal resistor whose resistive value changes with changes in surrounding temperatureĪ fixed value parallel plate non-polarised AC capacitor whose capacitive value is indicated next to its schematic symbolĪ fixed value polarised DC capacitor usually an electrolytic capacitor which must be connected to the supply as indicatedĪn adjustable capacitor whose capacitance value can be varied by means of adjustable plates Small variable resistors for mounting onto pcb’s

Two terminal fully adjustable rheostat whose resistive value varies from zero to a maximum value Three terminal variable resistance whose resistive value is adjustable from zero to its maximum value Power Supply Schematic Symbols SchematicĪ collection of single cells forming a DC battery supplyĪ constant DC voltage supply of a fixed valueĪ constant DC current supply of a fixed valueĪ dependent voltage source controlled by an external voltage or currentĪ dependent current source controlled by an external voltage or currentĮlectrical Grounding Schematic Symbols SchematicĮarth ground referencing a common zero potential pointĬhassis ground connected to the power supplies earthing pinĪ common digital logic circuit ground lineĪ fixed value resistor whose resistive value is indicated next to its schematic symbol The individual graphical symbols below are given along with a brief description and explanation. The basic electrical and electronic graphical symbols presented here are the more generally accepted graphical symbols because of their common usage across a range of electrical and electronic fields. For example, the IEC ( International Electrotechnical Commission) have one set of symbols, while the IEEE ( Institute of Electrical and Electronics Engineers) have an alternative set of symbols for the same component. For example, a potentiometer or rheostat.Īlthough electrical components are represented by universally accepted schematic symbols, there are a number of variants and alternative symbols used throughout the world to represent the same electrical component or device. Arrows are also used within schematic symbols to indicate the direction of convertional current flow around a circuit or through a component, or are used as part of their graphical symbol to show that the components has a variable or adjustable value. For example, the connecting leads of a bipolar junction transistor, (BJT) are identified as E (emitter), B (base), and C (collector).

A the connecting leads or pins of a component in a schematic diagram can be identified using letters or abreviations.

Circuit diagram symbols