Experiments Day 1 & 2Resistors, Potentiometers and Photocells.

You should have a kit of electronic parts.

First we will learn to identify the parts, then you will inventory them and later learn how they work

The breadboard lets you connect components without soldering (pronounced sodd-er-ing) meaning to melt metal to join parts.

You should have

• A 9 volt battery to provide power. It should always be unplugged and put in a separate bag before you put your kit away.

You should have

• Lots of resistors

• At least 10 wires

You should have

• A speaker for making sounds

• A push button switch to turn circuits on and off

You should have

• At least 1 battery snap to connect the battery to the breadboard. Red is positive, black is negative.

• Some LED lights

You should have

• A diode (it’s very small)

• Some transistors (there are 2 different kinds, you need at least 1 of each: a 3904 and a3906)

You should have

• A photocell that detects light. It’s flat and has sort of a zigzag pattern on top

• A SCR which is a kind of switch

You should have

• A variety of capacitors. The small ones are ceramic, the larger ones are can capacitors

You should have

• A potentiometer. It has a knob you can turn

• One IC (integrated circuit) which is a 555 timer

2 Battery Snaps

Battery

Speaker

SCR Capacitors

PhotocellPush Button

Transistors

Diode

3 LED’s

555 Timer

Potentiometer

15Wires

Solderless Breadboard

Inventory

1. Every day you receive your kit, TAKE INVENTORY.

2. Match all of the items in your kit with the inventory sheets in your kit.

3. Report any missing item to your teacher.

4. At the end of class, re-inventory your kit. Check around where you worked for any loose parts.

Learn how to identify the resistors

•Resistors have color bands on them•Colors are called the “color code”•4 bands on each resistor

•Band 1 = 1st Digit•Band 2 = 2nd Digit•Band 3 = Multiplier.•Band 4 = tolerance

•Gold = 5%•Silver = 10%If the 3rd band is

gold = /10 silver = /100

Most have 4 bands, the last band is usually silver or gold.

Lay the resistor with the silver or gold band to the right and write down the numbers for the first 2 bands followed by the number of zeros for the 3rd band.

Black Brown Red Orange Yellow Green Blue Violet Gray White

0 1 2 3 4 5 6 7 8 9

10 o

hm (

Bro

wn,

Bla

ck,

Bla

ck,

Go

ld)

2 @

47

ohm

(Y

ello

w,

Vio

let,

Bla

ck,

Gol

d)

2 @

100

ohm

(B

row

n,

Bla

ck,

Bro

wn

, G

old

)

3 @

220

ohm

(R

ed,

Red

, B

row

n, G

old)

3 @

330

ohm

(O

rang

e, O

rang

e B

row

n,

Gol

d)

470

oh

m (

Yel

low

, V

iole

t, B

row

n,

Gol

d)

4 @

1K

ohm

(B

row

n, B

lack

, R

ed,

Go

ld)

2.2K

ohm

(R

ed,

Red

, R

ed,

Gol

d)

3.3K

ohm

(O

rang

e, O

rang

e, R

ed,

Gol

d)

2 @

6.8

K o

hm

(B

l ue

, G

ray ,

Red

, G

o ld )

3 @

10K

ohm

(B

row

n,

Bla

ck,

Ora

nge,

G

old

) 16K

oh

m (

Bro

wn,

Blu

e, O

rang

e,

Gol

d)

2 @

33K

ohm

(O

rang

e, O

rang

e, O

rang

e, G

old)

120

K o

hm (

Bro

wn,

Re

d, Y

ello

w,

Gol

d)

470

K o

hm (

Ye

llow

, V

iole

t, Y

ello

w,

Gol

d)

Quantity Description Replacement Cost

26 Resistors 25 cents each

8 Capacitors 50 cents each

1 Potentiometer $1.50 each

1 Silicon Coated Rectifier $1.00 each

1 Diode 25 cents each

3 LED (Light Emitting Diode) 25 cents each

1 Photocell $1.00 each

2 9-volt battery lead 50 cents each

15 Solid Wires 10 cents each

1 555 Timer Chip 50 cents each

1 Push Button Switch $1.00 each

4 Transistors 50 cents each

1 Speaker $2.00 each

1 Solderless Circuit Board $6.00 each

1 9 volt battery $2.00 each

Review how a circuit works

Voltage is the electrical force that moves electrons through a conductor.

V

I R

CURRENT is the quantity or flow rate of electrons moving past a point within one second.

V

I R

                                                                                                                                 

                                                                                                                            

Resistance is the force that reduces or stops the flow of electrons.

V

I R

•Solderless Circuit Boards – The Bread Board

•On each side of the the “ditch” all the holes on each row are connected. •We use the bread board to construct electronic circuits that we want to test. •Because we do not use solder, it is easy to make changes and adjustments

This is the “ditch”. It separates the sides.

The holes are connected by rows not columns.