Electricity is Electronics Technology Education The future is looking bright!
Electricity isScience • Electricity is chemistry • Atoms contain protons and electrons • Electrons flowing from one place to another is known as electricity.
The atom Atoms: • contain electrons which are negatively charged • contain protons which are positively charged • want to have an even number of protons to electrons
Attraction Likes and Dislikes • Two positives repel +/+ R • Two negatives repel -/- R • A positive and a negative attract +/- A Magnets: • north & north repel n/n R • south & south repel s/s R • north & south attract n/s A
Cats chase birdselectrons chase protons • Electrons (-), Protons (+) • Electrons are attracted to the positive protons • Electrons want to pair with the protons until there is an equal number of protons to electrons.
Static electricity The carpet experiment • Rub your feet into the carpet (like a cho cho train). • Then…using your finger…touch a “friend” What happens…???
The Shocking Truth • When you drag your feet across the carpet…THINGS are jumping onto you. • Electrons jump onto your body and create an imbalance of electrons to protons • You are now negatively charged.
Your Unsuspecting Friend • Your friend is positively charged (extra protons) • When you sneak over and touch your “friend”, your extra electrons jump over to your “friend” • This movement causes a • The electrons then partner with your friend’s extra protons…creating a balance. Zap
To Make a Complete Circuit Summit Finish Start OBJECTIVE: You must return to where you STARTED… Puff puff
To Make a Complete Circuit An electrical circuit is complete when the electricity from the…. Power Source: Passes through…. Conductors: or Loads: And returns back to the power source through the… Battery Clip:
+ - The battery Cathode Anode Metal: positive charge Metal: Negative charge glass becker Acid
The battery Where do they "want" to be? + - Positive? Negative? ? e- ? e- e- e- e- e- e- e- e- ? ?
The battery the acid forces the electrons to the negative side. + - e- e- e- chemical force e- e- e- e- e- e-
The battery Create the Path; the electrons will flow to a "postive place" e- e- e- e- + - e- e- Air e- no resistance e- e- Acid chemical force chemical force e- e- e- e- e- e- e-
Back in the Acid electrons are forced back to the negative The battery let there be LIGHT e- e- + - e- e- e- e- e- e- e- chemical force e- e- e- e- e- e- e- e- e- e- e-
e- e- + - e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- e- Complete Circuit full circle (circuit). The electrons continue around and around. ? If this is true.... why do batteries lose power?
Dead Battery ? The acid losses it's power to force the electrons to the negative metal. ? + - e- e- e- e- e- e- e- e- e- Why move when you're happy where you are? e- e-
Closed Circuit vs. Open Circuit 1.2v Open Resister switch Closed switch 9v bat. wire 9v bat. Closed Circuit Open Circuit ? What is the purpose of the resisters ?
Series Circuit “closed circuit”
Series Circuit Open Circuit
Parallel Circuit Closed circuit
Parallel Circuit Open Circuit
Electrical Safety Grade 8 When you get to the Safety Rules site…move through the slides using the “next” and “previous” buttons. Take notes of the Safety rules. Neatness + completeness count…the notes will be submitted for marks. Click the link. then click then then then Safety Rules Safety First
Electrical Safety Grade 6/7 Click the link below and follow the instructions in Electrical Safety Grades K-6
Static Electricity Click the link below and follow the experiment for Static Electricity Grade K-8.
Printing Circuit Boards Step 1: We create our circuit boards by using a program called Autosketch. Autosketch is a computer aided drafting program (CAD).
Printing Circuit Boards Step 2: We clean all dirt, oxidation (rust), and oils from the copper circuit board. We use SOS pads (steel wool + soap) Copper coated Fibre glass board Scrub the entire surface, use a lot of pressure.
Printing Circuit Boards Step 3: Place the copper board, copper side up in the T-shirt press. Place the circuit layout, face down, on top of the copper. One or two boards: Heat 2 min. Three or Four boards: Heat 2 1/2 min.
Printing Circuit Boards Step 4: Remove the circuit board from the press. Write your full name and block on the GREEN side. Use permanent pen. Copper side Green side Georg Burns 2 When the board is cool...peel off the paper. Touch up missing ink spots with the permanent pen.
Printing Circuit Boards Step 5: Place the circuit board in the etching tank trays. The teacher will place them in Ferric Chloride acid. This will remove all unprotected copper from the fibre glass board. The permanent pen protects the copper, from the acid. Leaving the circuit layout.
Printing Circuit Boards Step 6: After the etching process is complete... remove the last of the ink with steel wool. You now have a professional quality Printed Circuit Board.
Drilling Prick punch the centre of all holes to be drilled.
Drilling Dremel drill using the "crab pincher" technique.
Soldering Process Soldering Pencil solder (tin,lead) lead copper pad copper solder side green parts side Part What is really going on?
Soldering Process What is really going on? Thermal molecular bonding. molecules lead copper pad Different metal molecules; Represented by different colour
Soldering Process As metals heat, the molecules separate. When the solder melts, it's molecules flow into the spaces. Soldering Pencil Solder copper pad Different metal molecules; Represented by different colour
Good solders = Great Electrical flow Outline of solder edge. Kiss shape means good molecular bond, between all 3 metals. Different metal molecules; Represented by different colour
Poor solders = Little or no Electrical flow Poor solder bond Outline of solder edge. Holes and copper pad showing, means there is a poor molecular bond. Different metal molecules; Represented by different colour
Solder shape = Electrical flow d d a c a d c a e b e a: Min. solder b: Optimal Solder c: Excess solder d: Poor shape e: Good shape