Cell

LED

PTM SWITCH

DIODE

BELL

VOLTAGE RAILS

BATTERY

FLASHING LED

PTB SWITCH

THYRISTOR

MICROPHONE

EARTH

RESISTOR

BI-COLOUR LED

SPST SWITCH

NPN TRANSISTOR

BUZZER

555 IC

VARIABLE RESISTOR

TRI-COLOUR LED

SPDT SWITCH

FIELD EFFECT TRANSISTOR

LOUDSPEAKER

OPERATION AMPLIFIER

POTENTIOMETER

PHOTO TRANSISTOR

CAPACITOR

AND GATE

LAMP

VOLTAGE REGULATOR

THERMISTOR

OPTO-ISOLATOR

ELECTROLYTIC CAPACITOR

OR GATE

MOTOR

CROSSING OF TRACK

LIGHT DEPENDANT RESISTOR (LDR)

AMMETER

PIEZO CRYSTAL OSCILLATOR

NOT GATE

VOLTMETER

JOINED TRACKS