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James Clerk Maxwell United electricity and magnetism into electromagnetism Nikola Tesla Invented three-phase electric power, as well as induction motor Georg Simon Ohm Had the resistance unit “Ohm” named after him in his honor, after he discovered the relation between voltage, current and resistance. Michael Faraday Published “On Magnetism,” had the capacitance unit “Farad” named after him in his honor Gustav Kirchhoff Coined the term “Blackbody Radiation” (relationship between absorption and emission of EV waves). Joseph Henry Discovered the phenomenon of self-induction, had the unit for inductor energy capacitance “Henry” named after him. AC Alternating current. Fluctuations from positive to negative. Hazards: hazards primarily stem from its 50–60 Hz frequency, which causes involuntary muscle contraction (tetany), ventricular fibrillation (heart stoppage), and breathing paralysis. Used in outlets, and frequency varies by country. DC Direct current. Little to no fluctuation. Hazards: severe electric shock (often causing "freeze on" muscle tetanus), high-intensity arc flash, thermal burns, and fire risks from ground faults. Batteries use this. UNITSSSSSS ANODE - POSITIVE CATHODE - NEGATIVE Battery Two parallel lines (one longer, one shorter) Switch A line with a gap and a “gate” tilted up
Transformer Two sets of coils facing each other. Consists of one or more coils (windings), usually centered on a ferrite core. These are called primary and secondary windings, and are electrically isolated from each other. Transfer electricity from one electronic circuit to another, can step up or step down voltage. Electricity is passed through primary winding, converted to magnetism in the ferrite core, then converted back into electricity in the secondary winding. The system only transfers electrical charge if the electrical current being input is being changed (such as in an AC input, rather than a DC input. KEY TERM Galvanic isolation - separation of output and input circuits. Potentiometer A zigzag line with an arrow pointing to it Lamp A circle with a cross/filament inside. A bulb with a resistance. Transistor A circle with three terminals (base, collector, emitter). Purpose is to amplify weak signals, and has several different modes of operation, determined primarily by how it is connected to the circuit. Has three terminals: Emitter, collector, and base (indicated by E, C, and B in image below). Two kinds of this: NPN (n type) and PNP (p type). NPN current flows from collector to emitter, while PNP flows from emitter to collector. Don’t exceed the voltage rating of the transistor, and keep in mind that transistors range from low to high frequency. Low frequency will not catch high frequency changes.
Only allows current to flow when a certain internal temperature is reached. Resistor A simple zigzag line, resists current, resistance measured in ohms Capacitor Two parallel lines of equal length, can be charged with any DC source, capacitance measured in farads (F, often abbreviated to μF due to small capacitances) be careful with voltage rating. Inductor A coil. Consists of only one winding, usually centered on a ferrite core, and only two terminals. Provides a delay to its output, as direct current will charge it magnetically. Like a sponge under a faucet, taking water into it until full, when the flow can pass through it again.
CALCULATIONS
Resistance in series : Add resistance values, continue with calculation Resistance in parallel : Voltage divider formula:
Invented by Alessandro Volta in 1800, the voltaic pile was the first true electric battery Gunn diode Uses a negative resistance region created by a GaAs structure to convert DC power into microwave signals Crystal diode Consists of a semiconducting crystal (e.g., galena, germanium, or silicon) and a fine metallic wire (cat's whisker) that allows current to flow in one direction. Snap-off diode Designed for ultrafast switching (sub-nanosecond) and generating short pulses, often used in microwave circuits and frequency multipliers Avalanche diode Specialized silicon junction diode designed to operate reliably in reverse bias breakdown, providing high-voltage surge protection and regulation without damage YES BUT WHAT IS RECTIFICATION??? Rectification is the process of converting alternating current (AC), which periodically reverses direction, into direct current (DC), which flows in only one direction, using diodes Kinds of rectifiers Bridge rectifier An a4-diode circuit configuration that converts alternating current (AC) into direct current (DC) by inverting the negative half of the AC cycle, providing full-wave rectification Half wave rectifier The simplest circuit for converting alternating current (AC) to direct current (DC), using a single diode to pass only the positive half-cycle of an AC waveform while blocking the negative half- cycle. High ripple, 40.6% efficiency. Full wave rectifier By using two or four diodes, it utilizes the entire input wave, achieving 81.2% efficiency and producing a smoother output with less ripple than half-wave rectifiers. Variable Resistor A resistor with a variable resistance. Lorentz Force The force exerted on a charged particle by electric and magnetic fields. It determines how charged particles move in electromagnetic environments. F = Force on a point particle q = Electric charge
E = External electric field v = Velocity of point particle B = Magnetic field USING A MULTIMETER
