INTRODUCTION TO ELECTRONICS

VOLTAGE The amount of potential energy between points in a circuit. Measured in Volts.

CURRENT The amount of charge flowing through the circuit over a period of time. Measured in Amps.

RESISTANCE How much a circuit resists the flow of charge. Measures in Ohms.

V = Voltage in volts I = Current in amps R = Resistance in ohms

BREADBOARD

RESISTORS

LED

i = LED forward current in Amps (found in the LED datasheet)

Vf = LED forward voltage drop in Volts (found in the LED datasheet)

Vs = supply voltage

555

The 555 Timer is one of the single most famous chips in the world. Invented in 1970, this pile of resistors and transistors function together as a programmable timer.

Ground - 1

Trigger - 2

Output - 3

Reset - 4

8 - Line Voltage

9 - Discharge

10 - Threshold

11 - Control

Gro

und

- 1

Trig

ger

- 2

Out

put

- 3

Rese

t - 4

8 - L

ine

Vol

tage

9 - D

isch

arge

10 -

Thre

shol

d

11 -

Con

trol

CAPACIToRStOrEs EnErGY

USeFUL FoR: TIMINg SURgE SUPpReSsIOn SIGnAL FILtErINg

Using a 1mF capacitor instead of 0.1mF causes each cycle to be twice as long.

Also, the value of R1 + R2 affects the “on” cycle, while R2 alone affects the “off” cycle.