Electrical Components and Units Reference SI Units Quantity

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Electrical Components and Units Reference

Electrical Components and Units Reference

SI Units Quantity Capacitance Charge Current Electromotive force Frequency Inductance (self) Period Potential difference

SI Units Quantity Capacitance Charge Current Electromotive force Frequency Inductance (self) Period Potential difference Power Resistance Temperature Time 2. 2 Quantity symbol C Q I E f L T V P R T t Unit Farad Coulomb Ampere Volt Hertz Henry Second Volt Watt Ohm Kelvin Second Unit symbol F C A V Hz H s V W Ω K s

Common Prefixes Prefix Name Meaning (multiply by) T tera 1012 G giga 109 M

Common Prefixes Prefix Name Meaning (multiply by) T tera 1012 G giga 109 M mega 106 k kilo 103 m milli 10 -3 micro 10 -6 n nano 10 -9 p pico 10 -12

Circuit Symbols 2. 14 Storey: Electrical & Electronic Systems © Pearson Education Limited 2004

Circuit Symbols 2. 14 Storey: Electrical & Electronic Systems © Pearson Education Limited 2004 OHT 2. 4

Storey: Electrical & Electronic Systems © Pearson Education Limited 2004 OHT 2. 5

Storey: Electrical & Electronic Systems © Pearson Education Limited 2004 OHT 2. 5

Battery: pushes on the electrical charges (though none will actually flow if the circuit

Battery: pushes on the electrical charges (though none will actually flow if the circuit isn’t complete) – the battery has two terminals labeled positive (+) and negative (-) – the most negative voltage region in the circuit, often the negative end of the battery, is sometimes called “ground” or 0 volts – the amount of push the battery supplies is the “battery voltage”, often 1. 5 V or 9 V or 12 V (with respect to ground) – as a battery gets worn out (or if it gets too cold!) its voltage will go down until the battery is too weak to continue to push current through the circuit symbol

Wire: provides a path through which electrical current can flow – ideally a wire

Wire: provides a path through which electrical current can flow – ideally a wire has no resistance symbol

Resistor: serves as a current path but limits the amount of electrical current flow

Resistor: serves as a current path but limits the amount of electrical current flow and reduces the pressure (i. e. drops the voltage) – resistance is measured in Ohms (Ω) – for resistors it doesn’t matter which way + and – are connected – when current flows through a resistor the resistor may get hot (i. e. it “dissipates” energy), so resistors can also be used as heaters symbol

Switch: place where a current path can be mechanically opened and closed, to start

Switch: place where a current path can be mechanically opened and closed, to start or stop the flow of electrical current – switches are used to turn things ON and OFF – place the switch in series with the component(s) it is meant to control, like a battery symbol

Capacitor: serves as a place to temporarily store electrical charge, like a temporary battery

Capacitor: serves as a place to temporarily store electrical charge, like a temporary battery – “charge it up” (store electrical charge) then “discharge it” (temporarily produce electrical current) – capacitance is measured in Farads (F) – electrolytic capacitors are ones in which it matters which way + and – are connected symbol

Diode: serves as a one-way valve, only allowing current to flow one direction under

Diode: serves as a one-way valve, only allowing current to flow one direction under normal circumstances – an LED (light emitting diode) is a diode (often red or green) that glows when current flows through it – diodes must be inserted the right way around for the circuit to operate correctly symbols

Voltage regulator: a chip that can be powered by a range of voltages but

Voltage regulator: a chip that can be powered by a range of voltages but uses internal circuitry to drop the voltage to output a very stable voltage (e. g. a “ 5 V regulator” might be able to run off any voltage from 6 V up to 20 V, but it always outputs exactly 5 V) – this is handy for providing a constant voltage to components even when dealing with batteries that can vary in voltage and circuits that can vary in overall resistance

IC (Integrated Circuit, AKA chip): a silicon chip with many tiny transistors on -board

IC (Integrated Circuit, AKA chip): a silicon chip with many tiny transistors on -board which can be programmed to make decisions (a microprocessor chip), to store digital information (a memory chip), to convert digital input to analog form (DAC), or vise versa (ADC), etc. – connects to other components through its multiple legs, called pins – be very careful never to put a chip in backward!

ADC (Analog to Digital Converter): a chip that takes analog (continuous) voltage input, perhaps

ADC (Analog to Digital Converter): a chip that takes analog (continuous) voltage input, perhaps from a sensor, and converts it to digital form for ease of use

Breadboard: a board into which components can be plugged and unplugged, allowing one to

Breadboard: a board into which components can be plugged and unplugged, allowing one to build and check circuits without having to be as permanent as soldering them together

PCB (Printed Circuit Board): insulating board onto which components can be soldered, with metallic

PCB (Printed Circuit Board): insulating board onto which components can be soldered, with metallic traces etched into the board to make electrical connections without having to use external wires

Perf. Board (Perforated (Circuit) Board): insulating board onto which components can be soldered, with

Perf. Board (Perforated (Circuit) Board): insulating board onto which components can be soldered, with no metallic traces etched between holes like on a PCB – using perf. board is more permanent than using a breadboard but you need to connect components with external wires

Transistor: 3 -leg device used in logic circuits so that a small/weak electrical current

Transistor: 3 -leg device used in logic circuits so that a small/weak electrical current at one point can control a much larger/more-powerful electrical current elsewhere in the circuit

Sensor: a device, often powered using +5 V and ground (+0 V) connections, that

Sensor: a device, often powered using +5 V and ground (+0 V) connections, that has a third output the voltage of which varies predictably and reproducibly as some physical parameter changes like temperature or air pressure – needs to be “calibrated” (i. e. the output needs to be checked using known physical conditions) so output values can be correctly interpreted

Socket: a dummy set of receptacles that matches the pins on a chip –

Socket: a dummy set of receptacles that matches the pins on a chip – the socket is soldered onto the board and the chip snaps into it so that the chip can be replaced (carefully!) without resoldering if it goes bad

Cable: a wire or set of parallel wires connecting components together – for example,

Cable: a wire or set of parallel wires connecting components together – for example, sensors often use a 3 -wire cable with the wires used for +5 V, ground (+0 V), and signal (output voltage)

Battery pack: a device for holding multiple (identical) batteries, either in series (+ of

Battery pack: a device for holding multiple (identical) batteries, either in series (+ of one battery attached to the – of the next, in which case the total voltage is the sum of the battery voltages) or in parallel (all + terminals connected together, all – terminals connected together, in which case the battery pack has the same voltage as each individual battery, but it will last longer (i. e. can provide current for a longer amount of time))

Audio jack: used to make a pull-beforeflight pin to start a flight computer just

Audio jack: used to make a pull-beforeflight pin to start a flight computer just before we let go without having to open up a payload box

Male and female headers: used to allow quick electrical connections between sensors, flight computers,

Male and female headers: used to allow quick electrical connections between sensors, flight computers, for programming, etc.

Shrink wrap: plastic insulation tubing one can slide over exposed metal, like a solder

Shrink wrap: plastic insulation tubing one can slide over exposed metal, like a solder joint, to insulate it electrically from nearby wires – shrink wrap contracts (shrinks!) when heated with a heat gun – think ahead; you might need to put the shrink wrap on before you do the soldering