www.YoYoBrain.com - Accelerators for Memory and Learning Questions for electronics

Category: Default - (192 questions) What electronic device is a breakover made to trigger in phase-controlled circuits 3 basic options for converting single phase to static, rotary, and electronic 3 phase power Define: static phase converter simplest/lowest cost option for converting single to 3 phase electricity Nothing more than a capacitor and a potential relay comprising a starter circuit Define: rotary phase converter consists of a 3-phase motor and some way of starting it, be it a rope and pulley or a well-designed static converter automatic start circuit converts single phase to 3 phase electricity Define: variable frequency drive a box of solid-state electronics that convert 3-phase 60 Hz AC to variable frequency 3-phase. Allows motors to be driven at different speeds Define: polarized plug a plug that must be plugged in correctly to reference line on ac plug or it will harm the equipment Define: Shockley diode special purpose diode with more 2 PN junctions (four-layer diode) uses a trigger voltage to switch the diode on What is the purpose of SSIFET transistors used in microwave frequency circuits Define: latching relay a relay where one control pulse closes the switch contacts and it remains closed until another signal tells it to release Define: component placement diagram used to show where components are layed out on circuit board Define: cold solder joints a rough and grainy solder joint; source of many problems on circuits Define: triode 3 element vacumn tube that equivalent to transistor amplifier Define: tetrode 4 element vacumn tube - similar to triode with 4th element reducing capacitive interference Define: varactor diode diode that incorporates the internal capacitance of PN junction allows electrical control of capacitance and is ideal for automatically tuning systems Define: fast-recovery diode responds to very short duration spikes and is used in high-frequency applications such as TV flyback circuit Purpose of three-state LED LED with 2 separate colors that light up depending on the direction of current. 3rd state comes from AC switching back and forth so rapidly eye sees blend of 2 colors Define: nematic liquid fluid is ordinarily transparent, but when a current is passed through it, it darkens and becomes opaque What are disadvantages of LED's difficult to see when ambient light is bright, also tend to eat up a lot of current especially when many are used Define: laser diode special type of LED that creates laser from NP junction Define: Darlington transistor where the output of 1 transistor is feed into base of another transistor Define: SCR (silicon-controlled ) a diode with a 3rd lead added the current will only flow when the 3rd lead has a current applied, but then will continue to flow even if current is removed from 3rd lead. Only turns off when current through diode is removed type of a switch used to control AC or DC currents, common in light dimmer switches Define: diac dual triggered diode that produces an output on each cycle 2 in parallel with opposite sides; used as a trigger for triacs Define: dual SCR; acts like 2 separate SCRs that are connected in parallel What is unique about VMOS transistors refinement of MOSFET; can handle higher powered than MOSFET and faster switching What is the purpose of IMPATT diodes (IMPact ionization Avalanche Transit-Time) is a form of high power diode used in high-frequency electronics and microwave devices. They are typically made with silicon carbide owing to their high breakdown fields The IMPATT diode is operated under reverse bias conditions. These are set so that avalanche breakdown occurs. This occurs in the region very close to the P+ (i.e. heavily doped P region). The electric field at the p-n junction is very high because the voltage appears across a very narrow gap creating a high potential gradient. Under these circumstances any carriers are accelerated very quickly. As a result they collide with the crystal lattice and free other carriers. These newly freed carriers are similarly accelerated and collide with the crystal lattice freeing more carriers. This process gives rise to what is termed avalanche breakdown as the number of carriers multiplies very quickly. For this type of breakdown only occurs when a certain voltage is applied to the junction. Below this the potential does not accelerate the carriers sufficiently. Once the carriers have been generated the device relies on negative resistance to generate and sustain an oscillation. The effect does not occur in the device at DC, but instead, here it is an AC effect that is brought about by phase differences that are seen at the frequency of operation. When an AC signal is applied the current peaks are found to be 180 degrees out of phase with the voltage. This results from two delays which occur in the device: injection delay, and a transit time delay as the current carriers migrate or drift across the device. The voltage applied to the diode has a mean value that means the diode is on the verge of avalanche breakdown. The voltage varies as a sine wave, but the generation of carriers does not occur in unison with the voltage variations. It might be expected that it would occur at the peak voltage. This arises because the generation of carriers is not only a function of the electric field but also the number of carriers already in existence. As the electric field increases so does the number of carriers. Then even after the field has reached its peak the number of carriers still continues to grow as a result of the number of carriers already in existence. This continues until the field falls to below a critical value when the number of carriers starts to fall. As a result of this effect there is a phase lag so that the current is about 90 degrees behind the vo What is purpose of BARITT diodes microwave frequency circuits What is the nominal voltage of a photovoltaic 0.5 V cell Define: voltage follower circuit amplifier circuit with unity gain - used for impedence matching and buffering Purpose of buffer amplifier prevents a later circuit from loading the signal source Purpose of Norton amplifier amplifies the difference in applied currents (versus voltages) Function of serial-analog delay (SAD) like a bucket brigade. Instantaneous signals are passed through a string of capacitors to delay signal Purpose of majority logic circuit count number of ON versus OFF signals and output equals the majority count Purpose of Schottky TTL circuits very fast switching diodes; 3.5 times faster than TTL but power consumption only doubled Difference between Class A, B, C amplifiers Class A - amplifies whole signal; great linear response but low efficiency Class B - amplifies only half signal; higher efficiency Class C - amplifies less than one half cycle; severly distorts signal but very efficient

Define: duty cycle of rectangular wave ratio between the high voltage time and low-voltage time of signal 4 types of signal modulation amplitude modulation frequency modulation phase modulation pulse code modulation Define: current gain ratio of collector current to base current amount the amplifier increases the current Define: MOSFETS metal-oxide-semiconductor field-effect transistors Define: potentiometer adjustable resistor Define: time constant of RC integrator T = R * C At T, the charge on the capacitor is 63.2% of supply voltage Define: zener the voltage where the zener diode will break down and conduct in the opposite direction of polarity Define: free-running multivibrator circuit supplies a series of clock pulses Define: comparator circuit compares 2 differenct voltages and switch on or off accordingly Define: combinational logic 0's and 1's flow through a network of logic circuits as fast as the circuits will allow. They do not pause and they are not stored for further use. Define: inverters reverse the logic state of the incoming signal Define: CMOS complementary metal-oxide-semiconductor type of integrated chip Define: DIPS dual-in-line package - with pins off of a plastic rectangle Define: monostable multivibrator mono - singe multivibrator - circuit that flips between 2 states a monstable flips just once and only when triggered ("one-shot") Define: switch bounce when a switch is closed or open, the contacts often fail to connect or separate cleanly. They may connect several times in quick succession before firm contact or complete separation occurs. Define: inductors device formed by winding a wire into a coil; when current passed through the coil, it resists the current for a while; same when current reverses it keeps going longer Define: peta 10 to the 15th one thousand million million Define: tera 10 to the 12th one million million Define: giga 10 to the 9th one thousand million Define: nano 10 to the -9th one thousandth of one million

Define: pico 10 to the -12th one millionth of one millionth Define: femto 10 to the -15th one thousandth of one millionth of one millionth Define: alto 10 to the -18th one millionth of one millionth of one millionth Define: BJT bipolar junction transistors - 2 types (NPN or PNP) Define: BUF function the output is equal to the input of signal Define: Karnaugh Maps technique for representing Boolean functions. Allows combining terms that are next to each other to make it simple to reduce the Boolean expressions Define: RS latch reset - set latch stores a value based on whether last signal was set = 1 or reset = 0 Define: D-Type Latch RS Latch with an enable signal added which tells the chip when to look at the values of the RS inputs Define: T flip flop circuit changes value every time the clock signal is received (no other inputs) Define: JK flip-flop circuit Reverses the output when the clock signal is received and both inputs are 0 or 1 Define: shift registers allow binary data to be shifted one bit at a time Define: PISO shift register parallel-in-serial-out shift register Define: SISO shift register serial-in-serial out Define: TTL transistor-transistor logic BJT connected in a certain way; fast but consume lots of energy Define: ECL transistor emitter-coupled logic substantially faster than TTL but consume more energy Define: SSI , MSI, LSI, VLSI, ULSI Small (1-12) Medium (13-99) Large (100-999) Very-Large(1,000-999,999) Ultra-Large(1,000,000)scale integration - number of transistors on a chip

Define: electromigration where the structure in the silicon of a chip are eroded by the flow of electrons Define: EEPROM electrically-erasable read-only memory Define: FLASH memory modification of EEPROM where memory can be selectively erased and reprogrammed versus all or nothing Define: PLD programable logic devices Difference between fusible-link and anitfuse fusible-link burns out unwanted connections PLD and antifuse burns in desirable connections Define: PLA programmable logic arrays - type of PLD where you can program both AND and OR arrays Define: PAL programable logic device programmable array logic (only AND is programmable which the OR array is predefined) Define: PROM programmable logic device programmable read-only memories - AND array is predefined and OR is programmable Define: CPLD complex PLD - class of devices that contains number of PLA or PAL functions sharing a common programmable interconnection matrix Define: FPGA field-programmable gate arrays - has an array of PLD's and a programmable switching matrix each vendor has proprietary architecture Define: ASIC application-specific integrated circuit - device whose function is determined by the designer for a particular application includes PLD, Gate Array, Standard Cell, and Full Custom Define: Gate Array Devices manufacture prefabricates wafers of chips containing unconnected transistors and resistors user passes a file telling manufacturer how to connect cells (groups of components) and they connect them Define: standard cells ASIC type of ASIC where there are blocks circuits that user tells manufacturer how to connect to perform desired function Define: full custom devices type of ASIC where designer has full control over ever aspect of chip manufature Define: glue logic simple interfacing functions Define: jelly bean parts devices containing small numbers of simple logic functions Define: PWB printed wire boards Define: laminates printed circuit boards Define: tinning electroless plating process used to coat the tracks and pads with a layer of tin-lead alloy on printed circuit board Define: LTH method for IC lead through hole - where IC are attached to circuit board by inserting their leads through holes drilled on the boards Define: SMT for circuit boards suface mount technology - component leads are attached directly to pads on the surface of the board Define: vapor-phase soldering solder is melted and the board lowered into the vapor-cloud above a tank containing boiling hydrocarbons Define: thermal relief pads used to make electrical connections on circuit board to the power and ground planes Define: Padcap used for high-reliability military operations; distinguished by the outer surfaces of circuit board only carrying pads with all electonics on interior surfaces Define: backplanes board that other boards plug into (like slots in back of computer) Define: COB chip-on-board : unpackaged IC's are mounted directly onto the surface of the board and then encapsulated with "globs" of epoxy resin Define: hybrid circuits typical hybrid contains a number of packaged or unpackaged IC's and a variety of discrete components all attached directly to the substrate Define: MCM multichip modules : when multiple unpackaged IC's are mounted directly onto a common substrate done because larger individual chips are hard/expensive to manufacture Define: coulombs (koo - looms) measurment for the amount of electricity Define: voltage divider rule the voltage across any resistor is that resistors percentage of the whole resistance in the circuittimes the voltage across the circuit Define: farad measure of capacitance the capacitance which will store 1 coulomb when a voltage of one volt is applied Define: corner frequency : definition and The frequency at which the RC circuits cuts equation off transmission = 1 / (R * C) R = resistance and C = capacitance Define: high-pass filter lets signal frequencies higher than its corner frequency to pass Define: low-pass filter RC filter that allows frequencies lower than its corner frequency to pass Define: diode transistion voltage point at which there is a sharp change in the conductivity on a diode Define: AC rectification change into DC current Define: bridge rectifier circuit of 4 diodes that uses both sides of AC current What is a SUS and use silicon unilateral switch - displays a negative resistance characteristic that makes it useful as a trigger device for SCRs What is PIC programmable intelligent controller Function of a logic probe tells you whether a signal is high or low Process for creating printed circuit board 1. coat the copper with a light-sensitive chemical layer called the sensitizer, also known as photoresist 2. Place an exact-size film negative of the circuit board layout drawing over the copper clad and exposing it. 3. Dip it in a resist developer. 4. Dip board in the etchant Define: embedded language interpreter a program that runs inside the microcontroller that allows a higher level language to be used to direct Define: OTP microcontroller one time programmable Define: unbalanced coaxil cable used to transport high frequency signals the center is wire is made of solid core copper and surrounded by insulative material (such as polyethylene) which separates it from the surrounding braided wire. The whole thing is surround by another insulator Define: hookup wire includes a tin-lead alloy to enhance soderability and is usually insulated with PVC. Used for hobby projects. Define: balanced coaxil cable similar to unbalanced but the core is two solid wired insulated from each other Define: impedence matching making the impedence of 2 devices that are to be joined equal Define: relays electrically actuated switches Define: transient suppressors a device used to prevent spikes in the current Define: chokes general-purpose inductors that act to suppress or limit fluctuating current while passing steady (dc) current Define: toroidal coil type of inductors with a coil that resembles a doughnut with a wire wrapping Define: tapped transformer have additional connection, or tap, on their primary and/or secondary windings that give the transformer 3 possible output voltages Define: multiple-winding transformer has a number of different secondary windings that are electrically isolated from each other. Define: autotransformer device uses a single coil and a tap to make a primary and secondary. Used to step up/down voltages but not for isolation because primary and secondary are on the same coil Define: JFET junction field effect transistors Define: UJT unijunction transistors - 3 lead devices that act exclusively as electrically controlled switches Define: 2 to 4 lead semiconductor devices that act exclusively as switches; much simplier to control than a transistor Define: optoisolators/optocouplers devices that interconnect 2 circuits by means of an optical interface. Could be a LED and a phototransitor or other implementations Define: integrator circuit the input signal is integrated (mathmatically) at the output Define: differentiator the input signal is differentiated at the output Define: positive feedback in an op amp involves sending output voltage back the noninverting input Define: comparator circuit compares 2 voltages Define: window comparator circuit changes its output state whenever the input voltage is anywhere between predetermined high and low reference voltages Define: crossover circuits filter network that divert low audio signals to woofers, middle-range frequencies to midrange speakers and high frequencies to tweeters Define: eleminates spikes and maintains a constant voltage output with load variations Define: line filter LC filter circuit that filters out unwanted high frequency interference Define: ring counter IC unique kind of shift register that incorporates feedback from the output of the last flip-flop to the input of the first flip-flop Define: Johnson shift counter IC similar to ring counter except that its last flip-flop feed data back ot the first flip-flop from its inverted output Define: recirculating memory register shift register that is preloaded with a binary word that is serial recirculated through the register via a feedback connection Can supply a specific repetive pattern What are the 2 Kirchhoff's laws 1.) Kirchhoff's voltage law: The sum of the voltage changes around a closed path is zero. 2.) Kirchhoff's current law: The sum of the currents that enter a junction equal the sum of the currents that leave a junction Define: rms voltage root mean square voltage - for sinusoidal voltage this value is 1/square root(2) * the peak voltage or .707 X peak Define: attenuation in a circuit when the voltage out is less than the voltage in Define: bandpass filter where the filter passes frequencies near a certain bandwidth and eliminates frequencies further away Define: notch filter filter passes all frequencies except a certain frequency where the response goes to zero from both directions What is a potted coil in a solenoid for environmental protection, the coil may be hermetically sealed (potted) Define: servomotor a motor whose output shaft can be moved to a specific angular position by sending it a coded signal What is the major difference between a servo's have feedback on the position and servo and stepper control system steppers don't What is an LDR light dependent resistor (photoresistor) Ohm's Law power equation Power = Voltage * amps power is in watts Define: VOM voltage-ohm meter Define: attenuator in many signal generators they are used to regulate the voltage of the output signal - it is a calibrated networks of resistors Define: AWG arbitrary waveform generators - can create many and complex waveforms Define: period of a waveform signal the time it takes for a signal to complete one full cycle Define: variac also known as the autotransformer, is a variable line current transformer Define: hygrometer test the chemical reactions in a battery to test it Define: varistor a resistor whose resistance is voltage dependent. Its resistance decreases as voltage across it is increased Define: inductor reactance and give formula opposition offered by inductor to ac current reactance in ohms = 2 * pie * frequency * inductance (in henries)

Define: zener diode limit voltage to a predetermined amount - cheap voltage regulator in reverse position will not allow current until a breakdown voltage is reached Define: rectifier basic diode that transforms AC current to DC only Define: peak current for LED the absolute maximum current that you can pass throught the LED for a very short period of time Describe a DPST switch double pole single throw - has 2 wires coming into it and 2 wires leaving. You can control 2 separate circuits with one switch - turning both on or off Describe a DPDT switch double pole double throw switch - 2 wires coming in and 4 wires leaving. It has 3 positions 1st postition - the first pair of wires connect 2nd position - all four output wires disconnect 3rd position - 2nd pair of output wires connect can be used to switch polarity of DC voltage going into a moter, etc Define: PIR motion detector passive infrared : contains 2 crystals that give off a charge when infrared light hit them. The infrared light is generated by any thing that is giving off heat Give Faraday's Laws Voltage induced by coil turning in magnet field depends on strength of magnet, speed of magnet (or coil), number of turns of coil and area of cross-section of coil Give Lenz's law The direction of induced EMF is such that it always opposes the change (movement) which causes it. Purpose of phase-locked loop type of linear IC which has an internally generated frequency that is compared to input. The voltage from the phase-sensitive detector is used to correct the oscillator frequency until the 2 signals are at the same frequency and in the same phase What is the definition of responsivity in the output signal / input signal using whatever context of any conversion component units are required for each form of energy What is the definition of detectivity of responsivity / output noise signal measurement device How would you measure the strain on a fastening a strain gauge material Define: resistive strain gauge piece of thin wire whose change of length is measured by sensing its change of resistance using a bridge circuit Define: piezoelectric strain gauge used to measure rapidly changing strains; useless for slowly changing strains but ideal for vibrational strains 2 methods for measuring pressure changes piezoelectric crystal or by way of a in gases and liquids diaphragm

Diaphragm separates the sensor from the liquid or gas whose pressure is being measured and allows more choice of sensing methods 2 methods for the absolute measurement of heat transfer with Pirani gauge (used for low gas pressure range 1mm down to 10^-3 ) ionization gauge (used for pressures below 10^-3mm down to lowest pressures obtainable )

Purpose of the Hall effect sensor detects direction by effect on constant current passed through a crystal. Magnetic field will cause the current carriers to be diverted, causing a voltage to appear between 2 faces. This current is in direct proportion to the size of the magnetic field. What are 2 common methods for distance radar and sonar sensing on large scale What are 2 differences between phototransistor is more sensitive by a factor phototransistor and photodiode performance as large as 1000 phototransistor has much slower response time (100 times slower) Use for pyroelectric films temperature sensors that are sensitive to radiated heat (infrared) Define: electret capacitor equivalent of a permanent magnet, a material that is permanently electrostatically charged What is the rule of thumb for sampling rate should be twice the highest frequency component in an analogue signal the balance between precision and excessive bandwidth is correctly struck Define: aliasing in sampling additional harmonics that are created by sampling errors. Frequency center around the sampling rate Definition of transfer function for a sensor show the functional relationship between the physical input signal and the electrical output signal function or graph of output versus input What is hysteresis in sensors when a sensor does not return the same output value when the input stimulus is cycled up or down variation duringchange Define: rheostats wire round resistor with a moveable slider that can make contact with the resistance wire at any point along its length. Has only 2 leads What is the purpose of hot-carrier diodes does not have PN junction No overshoot when it is switched from a forward-biased condition to reverse-biased condition, so reverse recovery time is fast. Used in microwave circuits Purpose of PIN diodes A PIN diode (p-type, intrinsic, n-type diode) is a photodiode with a large, neutrally doped intrinsic region sandwiched between p-doped and n-doped semiconducting regions. A PIN diode exhibits an increase in its electrical conductivity as a function of the intensity, wavelength, and modulation rate of the incident radiation. What is the purpose of quadrac it is a combined diac and triacs What does LASCR do light activated SCR (silicon controlled rectifier) Define: dedicated rheostats rhestats that are intended for high-power applications and designed to dissipate large amounts of heat Define: adjustable resistors meant to be adjusted once similar to a typical power resistor with an addition of metal ring that can be moved back and forth. Once the disired resistance is set, the metal ring is permanently clamped in place What is a tantalum capacitor physical shape of water drop; polarized; advantages over aluminum electrolytics - lower leakage, tighter tolerances, smaller size for equivalent capacity, and much higher immunity to electrical noise disadvantages - more expensive and limited capacity What is rule of thumb for RC time constant load time constant should be at least 10x as on rectification long as the charge interval Purpose and description of tunnel diodes heavier impurity doping; will be 3 voltage levels where the diode with exhibit negative resistance characteristics Category: Default - (58 questions) What type of current does an induction motor AC only requre Define: megger hand cranked device that imposes a high voltage to detect leakage current. Define: floating zone method method for growing single crystal components; grows thin wafers for electronics Define: tracks the connections on a circuit board Define: cladding sheet of copper covering raw printed circuit board Define: etchant strong acid-like liquid thats eats away the copper not protected by resistant Define: negative feedback when voltage is fed back from the output terminal to the inverting terminal Define: timbre represents the complex wave pattern that is generated when the overtones of an instrument are present along with the fundamental frequency Define: Czochralski process utilizes a seed crystal that is dipped into a silicon melt and then slowly pulled out while being rotated produces single-crystal silicon What are CHEMFET's used for used to detect absorbed species using FET which the gate is exposed to chemical sample Define: accelerometers sensing transducers that provide an output proportional to accleration, vibration and shock Define: graticule the matrix of squares on oscilloscope screen Define: rise time describes the scope's ability to accurately display voltages that rise very quickly Define: working voltage the highest voltage that a capacitor can withstand before the dielectric layers in the component become damaged Define: quantization noise and dither difference between actual amplitude and amplitude that can be encodedadded noise to digitized info to create more natural flow Define: amperometry based on H2O2 or O2 measurment reaction produces these molecules which are reduced at the electrode and this generates a current which can be measured Define: vias holes allowing connections between tracking layers What is difference between overtones and fundamental frequency is most intense fundamental frequency frequency overtones - other frequencies present

Define: epitaxy the growth of a vapor deposit or electrodeposit in which the crystal orientation of the deposit is directly related to the crystal orientation of the underlying crystalline substrate What are the 2 basic categories of light quantum detectors - convert incoming detectors radiation directly into an electron in a semiconductor device thermal detectors - simply absorb the energy and operate by measuring the change in temperature with a thermometer Define: IEPE generic industry term for sensors with built-in electronics Define: aliasing if you take samples at a rate less than twice the input frequency, the reconstructed signal has a wrong apparent frequency Define: conductimetric transducers measurement of changes in conductance due to the migration of ions Define: pads relatively large areas of aluminum constructed at the edges of each IC for testing and connection purposes Define: lithography (electronics) process by which the geometric patterns that define devices are transferred from a recticle to the substrate surface What is the relationship between the linear - the higher the wavelength the lower maximum operating temperature and cutoff the temperature the detector must be to work energy for a quantum photon detector properly Define: triboelectric effect where cable whip introduces noise, especially in high-impedance paths How can FET be used as a transducer the FET is capable of detecting changes in ion concentration when the gate is exposed to a solution that contains ions Define: overglassing the entire surface of the wafer is coated with a final barrier layer to provided physical protection for the underlying circuits Define: etching process by which entire films or particular sections of films are removed Define: pyroelectricity phenomenon in which a change in temp. causes thermal expansion which causes the appearance of charge Uses for capacitive sensors noncontact devices used for precision measurment of a conductive target's position or a nonconductive material's thickness or density Define: silicon bumbing additional metallization may be deposited on the pads to raise them fractionally above the level of the barier level Uses for inductive sensors noncontact devices used for precision measurement of a conductive target's position Define: wafer probing testing the individual IC's while they are still part of the wafer How does a Hall effect sensor work the transport of electrons through an electrical device is affected by the presence of an external device is affected by the presence of an external magnetic field. Define: die the completed circuits on a wafer before separation What principal do thermal anemometers use the principal that the amount of heat work on removed from a heated temperature sensor by a flowing liquid can be related to that fluid's velocity Define: die stacking several bare die are stacked on each other to form a sandwich What principle does differential pressure flow the concept that the pressure drop across meters work on the meter is proportional to the square of the flow rate How do cable position transducers (CPT) refer to all devices that measure work displacement via a flexible displacement cable that extracts from and retracts to a spring-loaded drum. The drum is attached to a rotary sensor What is linear variable differential a position-to-electrical sensor whose output transformer (LVDTS) - is proportional to the position of a moveable magnetic core What is a prepolarized microphone used an electrec so no DC source is necessary Function of sound intensity microphones permit the measurment of the energy flow in a defined direction How are array microphones used used for acoustic holography in which simultaneous recordings are made from a large number (16+) microphones in a fixed array 2 basic types of temperature sensing contact non-contact 3 families of temperature sensors electro-mechanical electronic resistive Acronym RTD resistance temperature detector Function of signal conditioning circuits transforming a sensor signal to be useful for analysis can include amplification, level translation, galvanic isolation, impedence transformation, linearization, and filtering Acronym ADC and DAC analog-to-digital converter digital-to-analog converter

What is a biosensor combination of bioreceptor with a transducerbioreceptor = biomolecule that recognizes the target analytetransducer - converts the recognition event into a measurable signal What are 3 major types of transducers used amperometry, potentiometry, and photometry in biosensors Define: potentiometry glass membrane or a polymeric membrane electrode is used for measuring the membrane potential resulting from the difference in the concentrations of H+ or other positive ions across the membrane Define: photometry the light from an indicator molecule is the measured signal How can you classify biosensors into 3 according to degree of integration of 2 generations components (method of attachment of biorecognition molecule to the base transducer element) 1st - biorecepter is physically entrapped in the vicinity of base sensor behind a descriminating membrane 2nd - immobilization of bioreceptor is achieved via covalent bonds 3rd - bioreceptor molecule becomes an integral part of base sensing element What are 2 types of spectrometers 1 - uses a rotating grating to disperse the light into separate wavelengths and scan the spectrum across a detector 2 - may be recongized by their mass (mass spectrometer) How does chromatography work varying molecular diffusivities are used to detect specific molecules gas is sent through a long column where the components of the sample diffuse at different rates through the column and this is detected at the end Describe how electrophoresis works an electric voltage bias is applied to column with a carrier fluid that is conductive steady flow of carrier fluid ions through the column which sweeps the sample along with it. The diffusivity differences for different sample componenets causes the sample to be spread out along the spectrum