Potential Dividers and their application as sensors Electricity Lesson 9.

Slides:

Advertisements

Similar presentations

Electric circuits 1.

Advertisements

3.3.1 Series and Parallel Circuits – Kirchhoff’s second law

5.5 The potential divider. 6V 3V 5.5 The potential divider.

P2.3.1 – Static Electricity. Objectives, to understand that: –When certain electrical insulators are rubbed together they become electrically charged.

What is electric current? What is current measured in? What is the difference between a series and parallel circuit? How many circuit symbols can you draw?

The Potential Divider Electricity Lesson 10. Learning Objectives To know what a potential divider is. To derive and know how to use the potential divider.

Physics and Electronics. Electronic systems Electronic systems are made up of 3 parts: 1)An INPUT SENSOR – these detect changes in the environment Examples:

Operational Amplifiers

Electricity and Magnetism Topic 5.2 Electric Circuits.

Electric Currents Topic 5.2 Electric Circuits. Electromotive Force Defining potential difference Defining potential difference The coulombs entering a.

5: Electric Current 5.2 Electric Circuits.

Electricity Define electric potential difference Determine the change in potential energy when a charge moves between two points at different.

1 D & T Design Lesson Sec 3B By: MdmLee Kah Gek Technological Areas - Electronics MacPherson Secondary School.

Twenty Questions Electronics. Twenty Questions

Conductors Metals and graphite are electrical conductors. Electrons are free to move in conductors. Electrons are negatively charged. The electrons carry.

1 LC1 Core Science Project.  Components :-  -Electrons Move from the (-ve) to (+ve) side -Electric current moves from (+ve) to (-ve) side -Energy is.

Series and Parallel Circuits Making Electricity Work for Us.

Potential Divider Circuits Sometimes elements on circuit need less than the total voltage potential. Circuit that can be adjusted to divide the p.d. (voltage)

Meter Mishaps. Use of Ammeters and Voltmeters Some V (energy) gets dissipated in ammeter. Some current leaks through voltmeter. Not really ideal.

Name: ________________ Class: _________________ Index: ________________ D.C. Circuit.

Resistive Transducers Sensors Used in Electronics.

Unit 6 in four lessons Resistors.

Electricity 2 Thomas Edison Lesson Objectives I know some circuit symbols for common components. I know what is meant by resistance I know.

Which of the signals below is a digital signal?

Beath High School - Int 1 Physics1 Intermediate 1 Physics Electronics Glossary AND gate to device digital signals to inverter LDR to logic circuit logic.

Engineering Science EAB_S_127 Electricity Chapter 2.

Twenty Questions Electronics. Twenty Questions

5.2.1Define electromotive force Describe the concept of internal resistance. Topic 5: Electric currents 5.2 Electric circuits.

18240 Element two - Components INPUTS OUTPUTS PURPOSE TYPICAL USE.

Electric Circuit Types Series and Parallel Circuits.

Chapter 20 Super Review Circuits. 1. What is the potential difference across a resistor of 6 Ω that carries a current of 3 A?

Engineering Science EAB_S_127 Electricity Chapter 3.

What we will do today Introduce potential divider circuits. Devise a formula comparing resistances and voltages in potential divider circuit.

ELECTRONICS – Input Transducers Engineering Science – National 5.

Voltage Divider Circuits Input transducers Input transducers are devices that convert a change in physical conditions (for example, temperature) into a.

Electric Circuits containing resistors. Circuits Charges travel in a circuit to maintain charge balance.

PHYSICS – Electric circuits

KEY WORDS: Insulating Electron Attract Repel Resistance Series ASSESSMENT: P2 REVISION – CHAPTER 4 – Current Electricity Electric symbols Electrical Charges.

Start + end ???? 1.2 Electric circuits Lesson starter

Direct current circuits

P2 Topic 2: Controlling and using electric currents

Series Circuit.

Electronic Components

Twenty Questions Electricity 1.

Draw a potential divider circuit where the output potential difference increases as the temperature of a thermistor increases. Hint: As temp of thermistor.

Potential Divider Aims What is a potential divider

Series Circuit – 1 bulb Series Circuit – 1 bulb.

P2 REVISION – CHAPTER 7– Electricity

Transistor & Voltage Divider

20.1 Series and Parallel Circuits

The resistance of a thermistor changes from 30k to 12k when the temperature changes from 20C to 70 C Calculate the sensitivity if resistance is taken.

Potential Dividers Electric Circuits ☞.

The rheostat (or variable resistor)

P2 Topic 2: Controlling and using electric currents

Calculating the resistance of a bulb

ELECTRONIC SYSTEMS Note: There is no compulsory question set on Section 25 of the syllabus. Questions set on topics within Section 25 are always set as.

Direct Current Circuits

P2 Topic 2: Controlling and using electric currents

Comparing Series and Parallel Circuits

Resistance components & Power

Electricity and Magnetism

P2 REVISION – CHAPTER 2 – Electricity Answers

Potential dividers (j) show an understanding of the use of a potential divider circuit as a source of variable p.d. (k) explain the use of thermistors.

Example Example 1: An electric lamp is rated 110 W, 200 V. When the lamp is operated at its rated power and voltage, calculate a) the current flowing through.

Passive Transducers Elliott.

Presentation transcript:

Potential Dividers and their application as sensors Electricity Lesson 9

Learning Objectives To know that a potential divider is a source of variable potential difference. To derive and know how to use the potential divider equation. To know that the load affects the output of a potential divider To know the applications of potential dividers; to detect temperature or light levels.

Question How do we get a variable supply voltage from a fixed one? How can we measure physical changes in position, temperature or light level etc.

Answer A potential divider is one way of producing a variable p.d. A combination of a suitable sensor (angle / position sensor, thermistor or LDR) and a potential divider enables measurement / monitoring / control of physical changes.

VSVS V1V1 V2V2 R2R2 R1R1

Deriving Potential divider equation For an unloaded potential divider the current is the same through both resistors So the voltage is proportional to the resistance

Potential divider equation If R1 >> R2 then V1 is more or less the supply voltage If R1 << R2 then V1 is close to 0 V. VS as an input to the potential divider and V1 as an output. The circuit itself provides a way to tap off a voltage between 0 V and VS.

V INV V out

Alternative formula The potential divider equation can be derived by rearranging the ratios above to give: V output = R1 / (R1+R2)  V input.

Using potential dividers Use as a volume, brightness or contrast control. Making and designing a circuit to use as a temperature sensor Making and designing a circuit to use as a light sensor Controlling logic devices

Effect of different resistive loads Output voltage is affected by load resistance Connecting a resistor across the output reduces the output voltage Shorting out across a bulb reduces the total resistance of the bulb – the wire is in parallel with the bulb

Example

Questions A series circuit is connected as shown in the diagram. 1.What is the potential difference between A and B? 2.An additional resistor of 100 W is connected between the 50 W resistor and the cells. What is the potential difference between A and B now? 3.The additional 100 W resistor is now connected in parallel with the first 100 W resistor. What is the potential difference between A and B now?