Section 6
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This document provides an overview of relays, 555 timers, and operational amplifiers. It defines each component and identifies their basic functions and applications. Relays are electromagnetic switches that control electrical current using a small input signal. 555 timers produce oscillating outputs that can be used for timing functions. Operational amplifiers are integrated circuits that amplify signals and can be used as comparators by comparing inputs. The document includes diagrams of each component and examples of their uses.
Section 6
- 1. Section 6: Relay,555timer & op- amp Creative Design & Innovation
- 2. Overview This section will give you the skills needed to understand the basic functions and application of :- - Relay - 555 timer. - Operational amplifier
- 3. Identify the basic functions and uses of a Relay. Identify the basic functions and uses of a 555 timer IC (integrated Circuit). Identify the basic functions of an Op-amp and calculate the gain. 1 2 3 Learning Outcomes
- 4. Relay A relay is an electromagnetic switch that can be enabled by a small electrical signal and controls a much larger electrical current. Integrated circuits are advanced circuits that contains many electronic components such as, transistors, diodes, resistors and capacitors, all fixed into a micro silicon chip. IC A quick change in the value of a signal, from the original value to a higher or lower one, then going back to the original value again. Puls e Electrical oscillation A regular variation about a certain central point in magnitude or position for current or voltage.
- 5. Electrical oscillation A regular variation about a certain central point in magnitude or position for current or voltage. Key Vocabulary A quick change in the value of a signal, from the original value to a higher or lower one, then going back to the original value again. Puls e
- 6. 1 Identify the basic functions and uses of a Relay.
- 7. Relay A relay is an electromagnetic switch that can be enabled by a small electrical signal. This internal magnetic switch can control a much larger electrical current.
- 8. How does a Relay work? Every Relay has a sensing unit, which is the electrical coil. The coil is powered by an AC or DC current. Electromagnetic Relay - Has an electromagnetic coil. - Has an armature. - Has a moving spring and contacts. - This relay is supplied by a DC current.
- 9. The way the Relay works is simple. There are two main circuits in a relay system. 1- Control Circuit. 2- Load Circuit. Some Relays have their switch contacts open by default. - Normally open (NO) - Normally colsed (NC Relays).
- 10. Types of Relay Electromagnet ic Relays Solid-state Relays
- 11. Types of Relay Solid-state Relays - Has no coil - Has no spring - Has no mechanical contact switch - Made from semiconductor materials - Have switching respone Electromagnetic Relay - Has an electromagnetic coil. - Has an armature. - Has a moving spring and contacts. - This relay is supplied by a DC current.
- 12. Activity 2.36
- 13. Relay applications We use relays for all electrical safety and switching systems.
- 14. Activity 2.37
- 15. 2 Identify the basic functions of an Op-amp and calculate the gain.
- 16. Operational amplifier Amplifires are devices that take a weak signal as an input and produce a much stronger signal as an output. Op-amp is a special kind of amplifier. We use it in Stereos and medical cardiograph. ( which amplify the heart beat)
- 17. Operational amplifier Op-amp are integrated circuits that combine many transistors, resistors and capacitors into a small silicon chip.
- 18. Operational amplifier+ PIC An op-amp has two different inputs: - The inverting input. - The non-inverting input. Signals going into The inverting input will be:- The non-inverting input will be:- Amplified Just amplified Inverted (flipped)
- 19. Operational amplifier One of the most common Op-amps is the LM741 Op-amp, it’s identical in appearance to the 555 timer.
- 20. Operational amplifier circuit diagram
- 21. Activity 2.38
- 22. Operational amplifier Applications Op-amp are often used as comparator to compare two inputs. ( The inverting input and non-inverting input) A common comparator is the temperature controller or thermostat on a central heating system to sense temperature and an op_amp.
- 23. Operational amplifier Applications The voltage at the non-inverting inputs is greater than the voltage at the inverting input. This means that the room temperature is less than the set temperature, and the op-amp switches on the heating system.
- 24. Activity 2.39
- 26. Gain of an operation amplifier Op-amp have a high voltage gain of around 100,00. Negative feedback is used to control the gain of an op-amp as shown below. The gain of an op-amp with negative feedback is calculated by: The minus ‘-’ sign shows that the output will always be inverted when compared to the input.
- 28. 3 Identify the basic functions and uses of a 555 timer IC (integrated Circuit).
- 29. 555 timer It is a single-chip version of a commonly used circuit called a multivibrator. For example:- We can use a 555 timer to make an LED blink ON and OFF. If we control the frequency, we are indirectly controlling the time, thus the name ‘timer’. 555 timers allow us to choose how frequently this blinking should occur (frequency).
- 30. 555 timer We can use 555 timer to produce an oscillated output.It is used in variety of timers:- - Pulse generator - Oscillator application It has three 5 KΩ resistors, thus has the name 555 timer. The 555 timer IC contains a lot of:- - Transistors - Resistors - Diodes
- 31. Do you have any question Thank You