1 Electronics and Control Technology. 2 Electronics and Control The 555 timer is an 8-Pin D.I.L....
Transcript of 1 Electronics and Control Technology. 2 Electronics and Control The 555 timer is an 8-Pin D.I.L....
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Electronics and Control
Technology
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Electronics and Control
The 555 timer is an 8-Pin D.I.L. Integrated Circuit or ‘chip’
What it looks like
Notch
Pin 1
3
Electronics and ControlOperation:•Contains 25 transistors, 2 diodes and 16 resistors
• Maximum operating voltage 16V
• Maximum output current 200mA
If you input certain signals they will be processed / controlled in a certain manner and will produce a known output.
INPUT PROCESS OUTPUT
• Best treated as a single component with required input and output
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What the 555 timer is used for:
•To switch on or off an output after a certain time delay i.e.
Games timer, Porch light, Childs mobile, Exercise timer.
•To continually switch on and off an output i.e.
Hazard warning lights, Soft toy, Bicycle indicators.
•As a pulse generator i.e.
To provide a series of clock pulses for a counter.
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Digital Terminology:
To use the 555 timer correctly you have to be aware of the correct terminology:
• Monostable Time
• Astable Time
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• MONOSTABLE: This is a system which has only one stable state.
It can be made to change but it will always return to its original stable state. A spring operated push button switch is an example of this. Monostable circuits are used as timers and as a single pulse generator.
7Monostable Circuit
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R1= 33k(Or/Or/Or)
R2= 1k (Br/Bl/Re)
R3= 470(Ye/Vi/Br)
R4= 470(Ye/Vi/Br)
2 No. LEDs
SW1= Toggle Switch
SW2= Tactile Switch
555 IC
3No.Terminal Blocks
Monostable PCB circuit layout:Component list:
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• ASTABLE: This is a system which has no stable state. It
changes from one state to the other all the time. A pendulum swings from one side to the other continuously. Astable circuits are used to flash lights or sound a loudspeaker. It can act as a square wave oscillator
10Astable Circuit
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R1 = 470(Ye/Vi/Br)
R2= 1k (Br/Bl/Re)
R3= 470(Ye/Vi/Br)
VR1= 100K
SW1= Toggle Switch
C1=10uF Capacitor
2 No. LEDs
555 IC
With VR1 set at 68K
flash rate = 1 per sec
Component list: Astable PCB circuit layout:
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R1=100 ohmsR2=100 ohmsR3=100 ohmsR4=2200 ohmsR5=1K ohmsVR1=100kC1=10uFQ1=BC 337-16D1=1N4148SW1=Toggle
Components Astable Project Board
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Warning signal: 4 LEDS flash simultaneously
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Buzzer and 4 LEDs Oscillate ON/OFF – Lorry Reversing
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Theme : A Safe Environment
Astable:Hazard / warning lights / school
crossingBicycle indicatorsBurglar AlarmSteep Gradiant IndicatorPersonal Alarm
Monostable:Egg Timer : Food / Electrical safetyBath / Oven Timer