ELECTRONICS AND SAFETY

Scarlett, Dash, Sam, Ashley, and Eric

Circuit Terms

Circuit- complete path of electric current Voltage- Potential difference Current- rate of flow of charge, electrons

moving along a conductor

DC vs. AC

Direct Current- electrons flow in a straight line (or forward)

Alternating Current (AC)- electrons keep switching directions In the US, AC is generated at 60 Hz,

meaning it alternates 60 times per second

Resistance

Contains two terminals and a semiconductor Carbon Ceramic

Size Width Length

ResistanceColor Numb

erMultiplier

Black 0 100

Brown 1 101

Red 2 102

Orange

3 103

Yellow 4 104

Green 5 105

But 6 106

Violet 7 107

Gray 8 108

White 9 109

Color Tolerance

Gold 5%

Silver 10%

Grounding

Limits static electricity A direct contact to the Earth The Earth’s voltage is zero Most AC current

Grounding in portable devices “A reference point in a circuit from which

all other voltages are measured” Ground plane

Conductive surface Near power source

Wiring/Circuit Conventions

US Conventions

Type Color

Power Red

Ground

Black, Blue

Signal White, Green, Yellow

How Dangerous is Electricity? Depends on current, voltage, and time

exposed DC current

300 mA is fatalBatter

yVoltage

(V)Capacity

(Ah)

AAA 1.5 1.15

AA 1.5 2.85

C 1.5 7.8

D 1.5 15

9 V 9 .5

12 V 12 120

How Dangerous is Electricity? AC current

In normal household outlets, 120 V 1 mA can be felt 5 mA is painful Above 15 mA, can lose muscle control,

fibrillation 70 mA can cause life-threatening irregular

heart rhythms

How to Protect Yourself

Soldering Unplug and turn off soldering iron when not

using it Use the wiring stand when using it

Don’t just put down on the table Clean off the soldering iron after use

How to Protect Yourself

Batteries Contains acid; can burn eyes, skin, and

clothing If visibly damaged; don’t use it Careful not to short out battery terminals

How to Protect Yourself

Unplug your circuit from your power source When plugging it back in make sure

everyone working on the circuit is aware Watch for any exposed metal or wire

Use electrical tape Double check your circuit

Using incorrect resistors can be dangerous