1. Child Pages

Child Pages

Analogue Switches
ContentsOverviewCrosstalkSwitching SpeedsPower ConsumptionExamplesIntersil ISL43L410Overview Analogue switches are electrical circuits which connect and disconnect analogue signals. They are also useful for certain digital signals which have analogue characteristics. An example would be the I2C bus. Although driven low (with sharp edges), the I2C bus lines are pulled high, causing the voltage to rise in a exponential fashion. Digital switches … Continue reading Analogue Switches
ContentsOverviewChild PagesOverview Batteries are, well, batteries. See the child pages for specific info! Child Pages Like this:Like Loading...
ContentsBluetooth 2.1ExamplesBluetooth 4.0Examples Bluetooth 2.1 Examples The Bluegiga WT12 bluetooth module supports iAP connectivity through their “iWRAP” Bluetooth stack. This bluetooth module can be connected directly to an iPod Authentication Coprocessor (through pins PIO5, PIO6 and PIO7) and will handle all the necessary authentication for you. Bluetooth 4.0 Examples The Bluegiga BLE112 and BLE113 are both … Continue reading Bluetooth
ContentsInsulation Materials And Their PropertiesStandardsNECComputer CableOverviewAWMUL2464Insulation Materials And Their Properties Common Name Material Temperature Range Features ETFE Ethylene tetraflouroethylene -70 to +150 Used in wire-wrap applications. MG Mica glass 450 Used in high-temperature applications Excellent thermal stability mPPE Modified polyphenylene ether -40 to +105 Excellent recyclability Excellent abrasion and cut-through resistance Superior dielectic properties to … Continue reading Cables
ContentsOverviewSchematic SymbolUsesTypesCeramicCeramic Di-electricsInsulation ResistanceElectrolyticTantalumConstructionPackagingPriceIssuesFilm CapacitorsPolyester (Green Cap)SupercapacitorsDoor Knob CapacitorsDielectric Constants Of Common MaterialsThe Dielectric Of AirCapacitors In Series And In ParallelCapacitors In ParallelCapacitors In SeriesFormulasChargeEnergyForceSingle Disc CapacitanceSphere CapacitanceParallel Plate CapacitanceConcentric Cylinder CapacitanceEquivalent Series Resistance (ESR)Leakage CurrentsHow Leakage Current Is SpecifiedWhy Leakage Currents Are ImportantMeasuring The Leakage Current Of A CapacitorVoltage DependenceDecouplingMains Line FiltersDielectric SoakageCharge Pumps … Continue reading Capacitors
Cellular Modems
ContentsOverviewTerminologyPower SupplyRough FiguresSIM CardsPCB Layout And Antenna RoutingSupported BandsGSMBands By CountrySoftwareExamplesDesign NotesOverview Most embedded modems are designed to communicate to a microcontroller over a UART interface. Some cellular modems also have embedded GPS decoders. Terminology Cellular modem design is FULL of acronyms/initialisms, here is a list to help you make sense of them: 1G 1G … Continue reading Cellular Modems
Circuit Protection
Like this:Like Loading...
Clocks And Timing
ContentsDelay LinesDelay Lines Delay lines usually have multiple output pins, each which is connected to a different point in the delay sequence. These are called taps. The number of taps is an important parameter of the delay line. Delay until first tap, and the incremental delay are also important parameters. Like this:Like Loading...
ContentsOverviewComparators vs. Op-AmpsGainTypesVoltage ReferencesHysteresisTermsPush-Pull Output ComparatorsNon-Inverting ConfigurationInverting ConfigurationOpen-Drain Output ComparatorsPCB Surface Leakage Overview Comparators are closely related to op-amps. A comparator is basically an op-amp which is operated in it’s open-loop mode (no feedback except for when hystersis is added). This is the schematic symbol for a comparator, which is the same as the op-amp. … Continue reading Comparators
ContentsOverviewChild PagesTerminologyConnector ManufacturersConnector MaterialsTin vs. Gold PlatingMass Pinned Header’sUSBJumpersSpring-Loaded (Pogo) ConnectorsCircular ConnectorsDIN ConnectorsMini-DIN ConnectorsTelecom ConnectorsBT ConnectorContactless ConnectorsOverview Unlike most other electrical components, most connector manufacturers do not append any letter codes in the part numbers for connectors, rather they are just a long sequence of numbers. This can make part recognition very confusing (e.g. when … Continue reading Connectors
ContentsOverviewRecharging DesiccantOverview Desiccant (a moisture absorbing compound), can be a good thing to use if your PCB is at risk for condensation. Recharging Desiccant Desiccant can be re-used, just by drying it in the oven. Put in on an oven tray. Set the temperature to 125°C. Set the timer to 5 hours. Be warned though, … Continue reading Desiccant
ContentsOverviewChild PagesParametersPolaritySchottky Diodes Zener DiodesPhoto Diodes Avalanche Photo-diodes (APDs)Bridge RecitifersTemperature SensorsSteering DiodesCan Diodes Share Current? Overview Diodes are passive semiconductor components consisting of a single P-N junction. Their main property is that they only allow conduction of current in one direction, which makes them a useful component in many electronic circuits. Child Pages Parameters These are some … Continue reading Diodes
ContentsOverviewDesignCommunicationUsesOverview A DPOT is a device which has a variable resistance which can be controlled digitally through some kind of communication protocol (such as SPI). They essentially behave like a potentiometer that can be controlled with a microcontroller rather than requiring human input. Design A DPOT usually is made from a string of closely matched, … Continue reading DPOT’s
ContentsOverviewEL WireEL PanelsOverview This page is about electrical devices that glow due to electroluminescence. For other electrical components that emit light, check out the IR Devices page, the LED page, LCD Screen page, or the OLED page. The principle way electroluminescence is created in current electronics is by applying an AC waveform across a thin layer … Continue reading Electroluminescence
Electropermanent Magnets (EPMs)
ContentsOverviewHow They WorkUsesElectropermanent Stepper MotorsExamplesOverview An electropermanent magnet (EPM) is a device which can have it’s magnetic field switched on/off by an electronic pulse. Once the pulse is applied, the magnetic field will retain it’s current state with the device unpowered. For a fixed amount of input electrical energy, EPMs can do a fixed amount … Continue reading Electropermanent Magnets (EPMs)
ContentsOverviewIncremental EncodersOverflow ProtectionEmbedded Hardware Encoder PeripheralsDatasheet ErrorsOverview Encoders are devices that measure the position of something. The word ‘encoder’ typically refers to a rotational encoder, although linear encoders do exist. Rotational encoders usually connect to a shaft (or have provision for one). Incremental Encoders Incremental encoders are encoders that output ‘step-change’ data, rather than an … Continue reading Encoders
Computer fans, PWM control, tachometer feedback, pull-up and more info about fans.
Ferrite Beads
Schematic symbols, important parameters, frequency response, equivalent circuit model, common uses, packages and more info about ferrite beads.
Info on FPGA's such as the Xilinx 7 Series (Artix, Kintex, Virtex or Zynq).
GNSS (GPS) Modules
ContentsTerminology FrequenciesAntenna BasicsGainPassive vs. ActivePolarizationVSWRTypes Of AntennasChipHelixesPatchRelativityCommunications With MicrocontrollerTerminology Term Description A-GPS A-GPS (or AGPS) is an acronym for assisted GPS. Chip antenna A type of antenna that can be used to receive GNSS signals. dB A logarithmic ratio used to measure the power gain or less in a RF circuit. dBi The directivity ratio between … Continue reading GNSS (GPS) Modules
Thermal resistance, phase-change compounds, forced convection, popular packages and more info on heatsinks.
ContentsOverviewTerminologyInductors In Series And In ParallelInductors In ParallelInductors In SeriesCommon Core MaterialsEquationsInductance EquationEnergy EquationSimple Impedance ModelParasitic ModelInductor NetworksInductors In ParallelInductors In SeriesImportant ParametersAir-cored InductorsAdvantagesDisadvantagesFerrite BeadsInductor KickbackSaturation CurrentRated CurrentSaturation Current vs. Rated CurrentInductor Packages Overview Inductors are passive electronic components which store energy as a magnetic field. They are made by coiling wire around a material … Continue reading Inductors
IR Devices
ContentsOverviewInfrared Emitting DiodesImportant parametersApplication CircuitsExamplesPhotodiodesImportant parametersDesign ConsiderationsApplication CircuitsExamplesBPW34FS – Silicon PIN Photodiode with Daylight FilterSFH2400xx – Silicon PIN Photodiode with Very Short Switching TimePhototransistorsImportant ParametersThermopilesPyroelectricsPassive Infrared Receiver (PIR) SensorsEmissivtiesMore InfoOverview Infrared devices are used commonly used in electronics for communication, object detection, electrical isolation and illumination. The vague and broad category of ‘infrared devices’ includes … Continue reading IR Devices
LCD Screens
ContentsCharacter LCD ScreensTypesContrastThe InterfaceMountingReverse-mounted Onto PCBTFT LCD ScreensSoftwareCharacter LCD Screens Types Character LCD screens can typically display 1, 2 or 4 rows of text between 16 and 20 characters wide. Various text and backlight colours exist. Most if not all have inbuilt driver IC’s which connect to the individual display segments, requiring only a 4-bit/8-bit … Continue reading LCD Screens
ContentsEEPROMUnique IDsFlashEEPROM Even though flash is technically a form of EEPROM, the word EEPROM is usually reserved to smaller-memory, read/write/erase 1 byte at-a-time ICs (flash is usually erased in pages and has way more memory). The cheapest EEPROM on the market is usually available with an I2C, 1-wire (e.g. UNI/O), or SPI-like (e.g. Microwire) interface, … Continue reading Memory
This app note below by Analog Devices explains microphone specifications really well. [gview file=””] Like this:Like Loading...
ContentsBrushed DC MotorsBrushless DC Motors (BLDC)Universal MotorsWeird MotorsStandard Motor SizesExternal LinksBrushed DC Motors Half-Bridge A half-bridge is useful if you only need to control the motor in one direction. A half-bridge allows acceleration, free-running, and deceleration in one direction. A half-bridge needs one high-side and one low-side switch, usually a P and N channel MOSFET. … Continue reading Motors
Neon Sign Transformers
ContentsOverviewUsesPicturesOverview Neon sign transformers are largish transformers that step up mains power to 6-15kV to power neon signs. They also happen to be very good fun to play around with if you are interested in high voltage stuff! Being cheap if you can find them for second hand on an auction site, they are simple … Continue reading Neon Sign Transformers
OLED Screens
ContentsOverviewReliabilityResolutions/Physical SizeCommunication/Connection MethodsDriver IC’sSolomon SSD1305Solomon SSD1306VCOMH, It May Not Be What You ThinkDriving Both The Charge Pump And Logic Of The Same SupplyEmbedded Graphics LibrariesManufacturers/DistributersOverview OLED’s are electronic screens that use miniature organic LED’s to display the picture. Since the pixels themselves emit light, unlike traditional LCD screens, they have no need for a backlight … Continue reading OLED Screens
Schematic symbols, configurations, feedback resistors, gain-bandwidth product, slew rate, cascading, isolation amplifiers and more info about op-amps.
Optical Isolators
Current-transfer ratios, phototriac outputs and more info about optical isolators.
Peltiers (Thermoelectric Cooler)
ContentsOverviewHistoryUsesConstructionImportant ParametersMax. Heat Transfer (Qmax)Max. Temp DifferentialMax. Operating TempHow Should I Drive One Of These?Examples Overview Peltiers are electrical components that use the Peltier effect to heat/cool objects. They act as a heat pump, moving heat energy from the cold side to the hot side. History The Peltier effect was discovered by Jean Charles Athanase Peltier … Continue reading Peltiers (Thermoelectric Cooler)
ContentsOverviewThe Piezo Schematic SymbolA Piezo’s Frequency ResponseHow To Drive A PiezoHow To Drive A BuzzerPiezo BendersMulti-layer Piezo SpeakersHomemade Piezo CrystalsExamplesOverview Piezo’s (in the electrical component sense), are small speakers that feature a piezo-electric crystal. When you apply a voltage, the crystal distorts, vibrating a plate and producing noise. They are very loud for their relatively … Continue reading Piezo’s
Resistive track material, taper, labelling standards, partial vs. multi-turn and more info about potentiometers (variable resistors).
Power Regulators
ContentsOverviewChild PagesTerminologyTopology SummaryDC/DC Converters And ControllersEfficienciesBurst ModeAC/DC ConvertersCurrent Sharing Buck-Boost Converter Joule Thiefs Overview Power regulators aim to convert an input DC voltage into a DC output voltage. There are many different ways of doing this, an each design has its benefits and advantages. The important parameters of DC/DC converters are efficiency, output ripple, complexity, and maximum … Continue reading Power Regulators
ContentsOverviewTerminology/ParametersMechanicalSolid StateContact ArrangementsInductive KickbackLatchingCommon Relay PackagesSuppliersOverview Relays are traditionally electro-mechanical devices used for switching electronic circuits. There now exists “sold-state relays”, which are purely electronic and contain no moving parts. Uses: Turing on mains voltage devices from 5-12V circuits, while providing isolation Switching large currents Relays with built in timers. Terminology/Parameters The Coil: The windings … Continue reading Relays
ContentsOverviewSchematic SymbolsResistors In Series And In ParallelResistors In Parallel.Resistors In Series.Resistor DividersVariable ResistorsTolerancesCan I Put Resistors In Series Or Parallel For Better Tolerances?Manually Tweaking ResistanceThe E SeriesManufacturing ProcessesThick FilmThin FilmMetal FoilPower ResistorsCurrent-Sense ResistorsJumpersVolume Resistance (Bulk Resistance)Packages Overview Resistors are a passive electronic component that restricts the flow of current when a given voltage is applied. … Continue reading Resistors
RF Shields
ContentsOverviewBoard-Level ShieldsOverview RF shields are components which are used to abosrb/dissipate RF noise/emissions. They are used both to protect sensitive circuits from external noise and to reduce the emmisions of noisy circuits. Board-Level Shields These are the most common types of RF shields, and are commonly just referred to as an “RF shield”. They are … Continue reading RF Shields
Satellite Modems
ContentsOverviewTerminologyIridiumAntennasQuadrifilarOverview Satellite modems are communication devices that use a satellite as a gateway to the destination device. This page focuses on satellite modems designed for embedded applications. They typically have tight technical voltage supply specifications (such as 40mVp2p voltage ripple and the ability to momentarily provide 1.5A of current during transmit mode). Terminology Term Description … Continue reading Satellite Modems
ContentsChild PagesChild Pages Like this:Like Loading...
Solar Cells
ContentsThe Peak Power PointPartial IlluminationSurface Area Based Specific PowerOperating Temperature RangeCharging BatteriesExternal LinksThe Peak Power Point To draw the most power from the solar panel, a certain current must be drawn from the panel at a certain voltage. 0% power draw occurs when the voltage is maximum and current is nothing (open-circuit), and when the … Continue reading Solar Cells
Oscillators, crystals and related info about timing-related components.
ContentsTransformation RatioPower EquivalenceMutual InductanceCoupling CoefficientNon-Ideal Transformer LossesResistive LossesHysteresis LossesEddy Current Losses Transformation Ratio For an ideal transformer, the voltage of the output (secondary) compared to the input (primary) is directly related to the ratio between the number of turns on the output compared to the input. $$ \frac{V_P}{N_P} = \frac{V_S}{N_S} $$ Power Equivalence Remember, energy … Continue reading Transformers
ContentsOverviewChild PagesTransistor Part Number Standards Overview Transistors are 3 legged active semiconductor devices. Child Pages Transistor Part Number Standards If you are lucky enough, the transistors you have will follow a naming standard. This allows you two identify (or partially identify) a transistor from bits of it’s part number.   Like this:Like Loading...
Schematic symbols, pin naming, component parameter descriptions, gate currents, part numbering and other information about TRIACs.
Vacuum Tubes
A vacuum tube is a device which controls a electric current through a vacuum created by a sealed container. Although none were “used” in the Columbus Radio project, the radio itself still had some beautiful valves in it (which I left in even though the valve circuitry is not used). Like this:Like Loading...