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
Resistance ColorNumberMultiplier Black010 0 Brown110 1 Red210 2 Orange310 3 Yellow410 4 Green510 5 But610 6 Violet710 7 Gray810 8 White910 9 ColorTolerance Gold5% Silver10%
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 TypeColor PowerRed GroundBlack, Blue SignalWhite, Green, Yellow
How Dangerous is Electricity? Depends on current, voltage, and time exposed DC current 300 mA is fatal BatteryVoltage (V)Capacity (Ah) AAA AA C D V V12120
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