100_IC_Circuits.pdf

For our other three free eBooks,Go to:1-100 Transistor CircuitsGo to:101-200 Transistor CircuitsGo to:50-555 Circuits See TALKING ELECTRONICS WEBSITE email Colin Mitchell:.auINTRODUCTIONThis is the third part of our Circuits e-book series.It contains a further 100 circuits.This time we have concentrated on circuits containing one or more ICs.Its amazing what you can do with transistors but when Integrated Circuits came along,the whole field of electronics exploded.ICs can handle both analogue as well as digital signals but before their arrival,nearly all circuits were analogue or very simple digital switching circuits.Lets explain what we mean.The word analogue is a waveform or signal that is changing(increasing and decreasing)at a constant or non constant rate.Examples are voice,music,tones,sounds and frequencies.Equipment such as radios,TVs and amplifiers process analogue signals.Then digital came along.Digital is similar to a switch turning something on and off.The advantage of digital is two-fold.Firstly it is a very reliable and accurate way to send a signal.The signal is either HIGH or LOW (ON or OFF).It cannot be half-on or one quarter-off.And secondly,a circuit that is ON,consumes the least amount of energy in the controlling device.In other words,a transistor that is fully turned ON and driving a motor,dissipates the least amount of heat.If it is slightly turned ON or nearly fully turned ON,it gets very hot.And obviously a transistor that is not turned on at all will consume no energy.A transistor that turns ON fully and OFF fully is called a SWITCH.When two transistors are cross-coupled in the form of a flip flop,any pulses entering the circuit cause it to flip and flop and the output goes HIGH on every second pulse.This means the circuit halves the input pulses and is the basis of counting or dividing.It is also the basis of a Memory Cell as will will hold a piece of information.Digital circuits also introduce the concept of two inputs creating a HIGH output when both are HIGH and variations of this.This is called logic and introduces terms such as Boolean algebra(Boolean logic)and gates.Integrated Circuits started with a few transistors in each chip and increased to mini or micro computers in a single chip.These chips are called Microcontrollers and a single chip with a few surrounding components can be programmed to play games,monitor heart-rate and do all sorts of amazing things.Because they can process information at high speed,the end result can appear to have intelligence and this is where we are heading:AI(Artificial Intelligence).In this IC Circuits ebook,we have presented about 100 interesting circuits using Integrated Circuits.In most cases the IC will contain 10-100 transistors,cost less than the individual components and take up much less board-space.They also save a lot of circuit designing and quite often consume less current than discrete components or the components they replace.In all,they are a fantastic way to get something working with the least componentry.A list of of some of the most common Integrated Circuits(Chips)is provided at the end of this book to help you identify the pins and show you what is inside the chip.Some of the circuits are available from Talking Electronics as a kit,but others will have to be purchased as individual components from your local electronics store.Electronics is such an enormous field that we cannot provide kits for everything.But if you have a query about one of the circuits,you can contact me.Colin Mitchell TALKING ELECTRONICS.auTo save space we have not provided lengthy explanations of how the circuits work.This has already been covered in TALKING ELECTRONICS Basic Electronics Course,and can be obtained on a CD for$10.00(posted to anywhere in the world)See Talking Electronics website for more details:http:/MORE INTROWe have said this before abut we will say it again:There are two ways to learn electronics.One is to go to school and study theory for 4 years and come out with all the theoretical knowledge in the world but very little practical experience.The other is to learn on the job.I am not saying one approach is better than the other but most electronics enthusiasts are not book worms and many have been dissuaded from entering electronics due to the complex mathematics surrounding University-type courses.Our method is to get around this by advocating designing,building,constructions and even more assembly with lots of experimenting and when you get stuck with a mathematical problem,get some advice or read about it via the thousands of free test books on the web.Anyone can succeed in this field by applying themselves to constructing projects.You actually learn 10 times faster by doing it yourself and we have had lots of examples of designs from students in the early stages of their career.And dont think the experts get it right the first time.Look at all the recalled electronics equipment from the early days.The most amazing inventions have come from almost newcomers as evidenced by looking through the New Inventions website.All you have to do is see a path for your ideas and have a goal that you can add your ideas to the Word of Invention and you succeed.Nothing succeeds like success.And if you have a flair for designing things,electronics will provide you a comfortable living for the rest of your life.The market is very narrow but new designs are coming along all the time and new devices are constantly being invented and more are always needed.Once you get past this eBook of Chips you will want to investigate microcontrollers and this is when your options will explode.You will be able to carry out tasks you never thought possible,with a chip as small as 8 pins and a few hundred lines of code.In two weeks you can start to understand the programming code for a microcontroller and perform simple tasks such as flashing a LED and produce sounds and outputs via the press of a button.All these things are covered on Talking Electronics website and you dont have to buy any books or publications.Everything is available on the web and it is instantly accessible.Thats the beauty of the web.Dont think things are greener on the other side of the fence,by buying a text book.They arent.Everything you need is on the web AT NO COST.The only thing you have to do is build things.If you have any technical problem at all,simply email Colin Mitchell and any question will be answered.Nothing could be simpler and this way we guarantee you SUCCESS.Hundreds of readers have already emailed and after 5 or more emails,their circuit works.Thats the way we work.One thing at a time and eventually the fault is found.If you think a circuit will work the first time it is turned on,you are fooling yourself.All circuits need corrections and improvements and thats what makes a good electronics person.Dont give up.How do you think all the circuits in these eBooks were designed?Some were copied and some were designed from scratch but all had to be built and adjusted slightly to make sure they worked perfectly.I dont care if you use bread-board,copper strips,matrix board or solder the components in the air as a birds nest.You only learn when the circuit gets turned on and WORKS!In fact the rougher you build something,the more you will guarantee it will work when built on a printed circuit board.However,high-frequency circuits(such as 100MHz FM Bugs)do not like open layouts and you have to keep the construction as tight as possible to get them to operate reliably.In most other cases,the layout is not critical.If you just follow these ideas,you will succeed.A few of the basics are also provided in this eBook,the first is transistor outlines:TRANSISTORSMost of the transistors used in our circuits are BC 547 and BC 557.These are classified as universal or common NPN and PNP types with a voltage rating of about 25v,100mA collector current and a gain of about 100.You can use almost any type of transistor to replace them and here is a list of the equivalents and pinouts:CONTENTSActivate after 3 ringsActive for 1 secondAdjustable Voltage Supply Alarm 4-ZoneAND GateAny Capacitor Value Any Resistor Value Battery Charger-Gell CellBattery-Low BeeperBFO Metal LocatorBrake Lights(flash 3 times)Burglar Alarm Burglar Alarm 4-ZoneClap SwitchConstant Current 20mACRO-100 LED CROCurrent LimitingDiceDomino EffectFlash LEDs for 20 SecondsGates Gell Cell Battery ChargerHome Alarm IntercomKnight Rider-Kitt Scanner Knight Rider for High-power LEDsKnock Knock DoorbellLadybug Robot Logic Gates Logic Probe-SimpleLogic Probe with pulseLong Duration TimerLow-Battery BeeperMains Detector Metal Detector-BFO Phone ChargerPhone ring detectorPhone RingerPolice LightsResistor Colour CodeSimple BFO Metal LocatorSimple Logic ProbeSolar TrackerTimer-Long Duration Transistor Tester-Combo-2Water Level Pump ControllerWheel Of Fortune 1.5v to 5v Phone Charger2-Sector Burglar Alarm 4 Pumps4-Zone Burglar Alarm10 LED Chaser10 Minute&30 Minute Timer10 Second Alarm 20mA Constant Current100 LED CROLED CRO LED DiceLED Zeppelin-a game of skill55574c14 RESISTOR COLOUR CODETHE 555The 555 is everywhere.It is possibly the most-frequency used chip and is easy to use.But if you want to use it in a one-shot or similar circuit,you need to know how the chip will sit.For this you need to know about the UPPER THRESHOLD (pin 6)and LOWER THRESHOLD(pin 2):The 555 is fully covered in a 3 page article on Talking Electronics website(see left index:555 P1 P2 P3)Here is the pin identification for each pin:When drawing a circuit diagram,always draw the 555 as a building block with the pins in the following locations.This will help you instantly recognise the function of each pin:Note:Pin 7 is in phase with output Pin 3(both are low at the same time).Pin 7 shorts to 0v via the transistor.It is pulled HIGH via R1.Maximum supply voltage 16v-18vCurrent consumption approx 10mAOutput Current sink 5v=5-50mA 15v=50mAOutput Current source 5v=100mA 15v=200mAMaximum operating frequency 300kHz-500kHzFaults with Chip:Consumes about 10mA when sitting in circuitOutput voltage up to 2.5v less than rail voltage Output is 0.5v to 1.5v above groundSources up to 200mA but sinks only 50mAHOW TO USE THE 555There are many ways to use the 55.(a)Astable Multivibrator-constantly oscillates(b)Monostable-changes state only once per trigger pulse-also called a ONE SHOT(c)Voltage Controlled Oscillator ASTABLE MULTIVIBRATOR The output frequency of a 555 can be worked out from the following graph:The graph applies to the following Astable circuit:The capacitor C charges via R1 and R2 and when the voltage on the capacitor reaches 2/3 of the supply,pin 6 detects this and pin 7 connects to 0v.The capacitor discharges through R2 until its voltage is 1/3 of the supply and pin 2 detects this and turns off pin7 to repeat the cycle.The top resistor is included to prevent pin 7 being damaged as it shorts to 0v when pin 6 detects 2/3 rail voltage.Its resistance is small compared to R2 and does not come into the timing of the oscillator.Using the graph:Suppose R1=1k,R2=10k and C=0.1(100n).Using the formula on the graph,the total resistance =1+10+10=21k The scales on the graph are logarithmic so that 21k is approximately near the 1 on the 10k.Draw a line parallel to the lines on the graph and where it crosses the 0.1u line,is the answer.The result is approx 900Hz.Suppose R1=10k,R2=100k and C=1uUsing the formula on the graph,the total resistance =10+100+100=210k The scales on the graph are logarithmic so that 210k is approximately near the first 0 on the 100k.Draw a line parallel to the lines on the graph and where it crosses the 1u line,is the answer.The result is approx 9Hz.The frequency of an astable circuit can also be worked out from the following formula:1.4 frequency=(R1+2R2)C555 astable frequenciesCR1=1kR2=6k8R1=10kR2=68kR1=100kR2=680k0.001100kHz10kHz1kHz0.0110kHz1kHz100Hz0.11kHz100Hz10Hz1100Hz10Hz1Hz1010Hz1Hz0.1HzThe simplest Astable uses one resistor and one capacitor.Output pin 3 is used to charge and discharge the capacitor.LOW FREQUENCY OSCILLATORSIf the capacitor is replaced with an electrolytic,the frequency of oscillation will reduce.When the frequency is less than 1Hz,the oscillator circuit is called a timer or delay circuit.The 555 will produce delays as long as 30 minutes but with long delays,the timing is not accurate.555 Delay Times:CR1=100kR2=100kR1=470kR2=470kR1=1MR2=1M102.2sec10sec22sec10022sec100sec220sec470100sec500sec1000sec555 ASTABLE OSCILLATORSHere are circuits that operate from 300kHz to 30 minutes:(300kHz is the absolute maximum as the 555 starts to malfunction with irregular bursts of pulses at this high frequency and 30 minutes is about the longest you can guarantee the cycle will repeat.)SQUARE WAVE OSCILLATORA square wave oscillator kit can be purchased from Talking Electronics for approx$10.00See website:Square Wave OscillatorIt has adjustable(and settable)frequencies from 1Hz to 100kHz and is an ideal piece of Test Equipment.555 Monostable or one Shot50-555 CIRCUITS50 555 Circuits eBook can be accessed on the web or downloaded as a .doc or.pdf It has more than 50 very interesting 555 circuits and data on using a 555.Table of Contents:(more has been added-see:50-555 circuits)Active High TriggerActive Low TriggerAmplifier using 555Astable MultivibratorBi-Coloured LEDBi-Polar LED DriverCar TachometerClark ZapperClicks UnevenContinuity TesterDark DetectorDriving A Bi-Coloured LEDDriving A RelayFlashing IndicatorsFlashing Railroad LightsFlip FlopFunction of each 555 pinHee Haw SirenHigh Frequency 555 OscillatorHow to use the 555Increasing Output CurrentIncreasing Output Push-Pull CurrentInverter 12v to 240vInside the 555Kitt ScannerKnight RiderLaser Ray SoundLatchOne-Shot 555OrganPolice SirenPulse ExtenderPulser-74c14PWM ControllerRailroad Lights(flashing)Rain AlarmReplacing 556 with two 555sResistor Colour CodesScreamer Siren-Light ControlledServo TesterSimplest 555 OscillatorSiren 100dBSquare Wave OscillatorStun GunSubstituting a 555-Part 1Substituting a 555-Part 2Switch DebounceTachometerTicking BombTilt SwitchTouch SwitchToy OrganTransistor TesterTrigger Timer-74c14Uneven ClicksUsing the 555LED DimmerLight Controlled Screamer SirenLight DetectorLow Frequency 555 OscillatorMachine GunMemory CellMetal DetectorMonostable 555Morse KeyerMosquito RepellentMotor PWMMultivibrator-AstableNegative VoltageNormally Closed TriggerVoltage DoublerWailing SirenZapper(Dr Clark)Zener Diode Tester2 Minute Timer-74c1410 Minute Timer-74c1412v to 240v Inverter100dB Siren555 Amplifier555 Kit of Components555 Pinout555 Mistakes(No-Nos)556 Dual Timer KNOCK KNOCK DOORBELLThis very clever circuit only produces an output when the piezo detects two taps.It can be used as a knock-knock doorbell.A PC board containing all components(soldered to the board)is available from talking electronics for$5.00 plus postage.Email HERE for details.The circuit takes only a few microamp and when a tap