1. TEST YOUR BRAIN!
Components

2. Resistor A resistor limits the amount of current flowing in a circuit
Symbol

3. The resistance between the centre pin and the other two depends on the
Preset Resistor
Variable Resistor
(Potentiometer)
The resistance between
the centre pin and the
other two depends on the
position of the wiper.
Symbol
Symbol

4. Capacitor A capacitor stores electrical charge
Polyester (non-polarised)
Electrolytic (polarised)
100uF 16V
100nF
100V
Symbol
Symbol

5. LDR The resistance of an LDR decreases as it gets lighter Light
Dependent
Resistor
The resistance of an
LDR decreases as it
gets lighter
Symbol

6. LED An LED produces light when connected the right way round. Light
Emitting
Diode
An LED produces light
when connected the
right way round.
The Anode must be positive
The Cathode must be negative
Anode
Cathode
Symbol
Cathode
Anode

7. Diode A diode only allows current to flow in one direction.
Anode to Cathode
Cathode
Anode
Cathode
Anode

8. Transistor The current flowing through the transistor is controlled
by the current flowing
into the base.
Base
Collector
Emitter

9. The current flowing through
FET
Field
Effect
Transistor
The current flowing through
a FET is controlled by
the voltage on the gate.
Source
Drain
Gate
IRF530

10. Thyristor A thyristor is a latch, it only conducts once
(SCR)
A thyristor is a latch,
it only conducts once
triggered by a voltage
on the gate.
TIC106
Anode
Cathode
Gate

11. Integrated Circuit (chip)
555
Timer
A 555 timer is an
Integrated Circuit (chip)
used to create delays
and pulses.
NE555 1 2 3 4 8 7 6 5

12. PIC A PIC is a programmable chip that can perform a range of functions
Peripheral
Interface
Controller
A PIC is a programmable
chip that can perform
a range of functions
set by the program.
PIC08M 1 2 3 4 8 7 6 5
+5V
Output 0
Input 1 / Output 1
Input 2 / Output 2 0V
Serial In
Input 4 / Output 4
Input 3