Aerial(Antenna) A device, which is designed to receive or transmit radio signals. It is alsoknown as an antenna.

Meters and OscilloscopeComponent Circuit Symbol Function of Component

Voltmeter 

 

A voltmeter is used to measure voltage.The proper name for voltage is 'potential difference', but most people prefer to say voltage!Amp-meter 

 

An amp-meter is used to measure current. As known as ampsGalvanometer A galvanometer is a very sensitive meter which is used to measure tinycurrents, usually 1mA or less.Ohmmeter 

 

An ohmmeter is used to measure resistance. Most Multimeter have anohmmeter setting.OscilloscopeAn oscilloscope is used to display the shape of electrical signals and it canbe used to measure their voltage and time period.

Sensors (input devices)Component Circuit Symbol Function of Component

LDRA transducer which converts brightness (light) to resistance (an electricalproperty).LDR = Light Dependent Resistor Thermistor 

 

A transducer which converts temperature (heat) to resistance (an electricalproperty).

Logic Gates

Logic gates process signals, which represent

true

(1, high, +Vs, on) or 

false

(0, low, 0V, off).There are two sets of symbols: traditional and IEC (International Electrotechnical Commission).

GateTypeTraditional SymbolIEC SymbolFunction of Gate

NOT

 

A NOT gate can only have one input. The 'o' on the output means'not'. The output of a NOT gate is the inverse (opposite) of itsinput, so the output is true when the input is false. A NOT gate isalso called an inverter.