Transducers

https://goo.gl/q7mCt8

TRANSDUCERS

          Every move we execute, there is an amazing action behind it. Have you wonder how the food we take in continually supply energy? We know that we eat food for survival but if we go deeper, we will be amazed how amazing life is. It is the transformation of chemical energy from food into mechanical energy which pertains to our ability to move. We could even state it as an example of natural transducer.

I. Definition

http://goo.gl/0KAt0E

         Transducers from the root word itself, “transduce” which means to transform. If we will define transducers, it would be defined as transformers. Transducers are so called devices that transform one form of energy to another for practical purposes. Yet, it justifies the law of conservation of energy which states that “Energy cannot be destroyed, it will only keep on transforming from one type to another. “

II. Types of Transducers 

       1. Electrical Transducers

This type converts mechanical energy into electrical energy. The mechanical energy can be in a form of velocity or flow and the output is in the form of current.



The following are some of commonly used electrical transducers:



        1) Potentiometers

           The output is the change in resistance from change in displacement.

https://goo.gl/KODF8g

        2. Magnetic sensor.

           Detects change in displacement forming into change in inductance and formation of eddy current.

https://goo.gl/1hA8Al

       3. Photo Electric Transducer.

         Converts light into voltage that will yield electricity.

https://goo.gl/dJIM4A

III.    Another Classification for the Types of Transducers

http://goo.gl/YGx3lN

1. Piezoelectric Transducer

           Piezoelectric Transducer converts mechanical energy into electrical energy and vice versa. These are used in detection of the stick’s impact in electronic drum pads. These could also be used in detecting the movements of muscles which is called acceleromyography.

http://goo.gl/YGx3lN

https://goo.gl/aRy5q9

2. Pressure Transducer

          Pressure transducer is a special type of pressure sensor that converts the detected pressure into electrical signals. Pressure transducers are also known as pressure indicators, transmitters, manometers, piezometers, and pressure sensors.

https://goo.gl/2JCQnz

3. Temperature Transducer

          Temperature transducer is a device that can convert the recorded temperature of a system or device into other forms such as electrical energy or mechanical energy or pressure, which will be then be sent to the system for controlling the temperature of it.Temperature transducers are used for measuring temperature of air to control the temperature of heating, air-conditioning, ventilation, and others. 
 

https://goo.gl/aRy5q9

https://goo.gl/Oe6rlL

4. Ultrasonic Transducer

          Ultrasonic transducers convert ultrasound waves into electrical signals and electrical signals back to ultrasound waves. This type is also called as piezoelectric or capacitive transducers.The used of ultrasonic transducer is for measuring distance based on the reflection of sound. 

 

https://goo.gl/aRy5q9

https://goo.gl/aRy5q9

VI. References:





Retrieved on September 8, 2015 from http://www.brighthubengineering.com/hvac/42103-types-of-transducers-electrical-transducers/





Retrieved on September 8, 2015 from http://efxkits.com/blog/different-types-of-transducers-in-practical-applications/

Potentiometer

POTENTIOMETER

I.                    Introduction

Potentiometer is known to be an example of a resistor which generally comes in variable. Meaning, its resistance is adjustable with the help of an adjusting knob. Potentiometer is also commonly called “pot” in short. This chapter will give you an idea of what is a potentiometer, its composition and types and its application to the world of electronics.

II.                    Parts

https://goo.gl/Sb1uXR

https://goo.gl/93f9Sw

 

III.                    Types

A.      According to Composition

Common materials that are used to construct potentiometers include

1.       Carbon – commonly used type with the composition of carbon in an insulating wafer.

https://goo.gl/M29EqF

2. Cermet – preferably to use in high temperature because of its ceramic and metallic composite. 

https://goo.gl/vQGf2w

 

3. Wirewound- coils of wire are being wounded used in high power connection.

 

 http://goo.gl/WgT2SX

4. Conductive plastic or metal film – special plastic material is used and known to be its excellent performance and high quality.

https://goo.gl/IdE0za

B. According to Varying Resistance

1. Adjustable – common type where the manipulation is done in the potentiometer itself. 

http://goo.gl/REc71t

2. Preset – from the name itself it means that the manipulation is set before connecting in a circuit.

 

 

https://goo.gl/c1VNuV

3. Digital – the variation of resistance is though electronic input. 

  

https://goo.gl/qrL6zH

    C.  According to the Track of Manipulating

                1.       Linear. The manner of manipulating is through sliding in a linear way.  

https://goo.gl/czSDv3

                                2. Rotary. The manner of manipulating is through rotating the knob. Example for this is the volume knob of our radio. 

https://goo.gl/TkSRbR

IV. Applications


If we account all the applications of a potentiometer, it will be difficult. But we will have the common application of it that is much known to us.


1. Audio control. This refers to the control of the sound. Behind the volume knob of our audio devices is the presence of potentiometer.


2. Light control. This also refers to the control of light brightness. Example form this is the dimmer used in some homes. 

 

V.                  Potentiometer symbols

http://goo.gl/y15IIR

Reference:


1. Variable Resistors. Retrieved on August 31, 2015 from http://www.electronics-radio.com/articles/electronic_components/resistors/variable-resistors-potentiometers.php

 

     Laboratory Experiment 

                

                                                                   Potentiometer  

I.                    Objectives: This laboratory experiment aims to

                    

a. Use potentiometer in a circuit

b. Manipulate the potentiometer in different voltages

c. Give particular applications of potentiomter

II.                  Materials:

          

· AC-DC converter

· Alligator clips


· Bulb

· Potentiometer

· Resistor (1100 Ω)

· Multitester

III.                    Procedures:

       

1. Record the resistance of the bulb and the resistor.

2. Set up a circuit having a bulb and potentiometer in a series.

3. Gradually increase the voltage source for atleast five times.

4. Get the actual voltage output.

5. Manipulate the potentiometer by rotating its knob in every increase of voltage output.

6. Obtain Vdrops when the potentiometer is closed, half-opened and opened.

7. Observe the brightness of the bulb when potentiometer is manipulated.

8. Provide table for your data.

9. Insert a resistor in the set-up.

10. Repeat procedures from 1-7.

11. Record data on another table.

IV.                  Data and Results:

 

VOLTAGEOUT (V)	VOLTAGEDROP (v)
	CLOSED POT	HALF-OPENED POT	OPENED POT
3.1 V	2.8 V	1.4 V	0V
5.2 V	4.6 V	2.2 V	0V
7.2V	6.8 V	3.5 V	0V
9.2V	9.0 V	4.3 V	0V
12V	10 V	4.8 V	0V
BRIGHTNESSBULB	BRIGHT	DIM	NO LIGHT

 

Observations: I observed that the voltage drops as well as the light of the bulb are affected as the potentiometer is opened.

Table B: POT with FIXED RESISTOR R= 1100 Ω RBULB= 20 Ω

VOLTAGEOUT (V)	VOLTAGEDROP (v)
	CLOSED POT	HALF-OPENED POT	OPENED POT
3.2 V	2.2 V	1.1 V	0 V
5.2 V	3.9 V	1.8 V	0 V
7.4 V	5.8 V	2.7 V	0 V
9.4 V	7.6 V	3.8 V	0 V
12V	8 V	4.2 V	0 V
BRIGHTNESSBULB	BRIGHT	DIM	NO LIGHT

Observations: Same thing happened with the first set-up. The Vdrops decreased until became zero.



        Based on the data, it is can be concluded that potentiometer really affects the current with its resistance value that can be manipulated. As the potentiometer is totally opened, current is zero causing to have no light in the bulb.

         

V. Post-laboratory Questions:

1. What happened to the Vdrops as the potentiometer was gradually opened?


 As the potentiometer was gradually increased, the Vdrops were decreasing until it became zero.


2. How will you describe the light of the bulb? What is the implication of the decreasing intensity of the bulb as the potentiometer was gradually opened?


The light of the bulb was getting dimmer as the potentiometer was gradually opened. The decreasing light of the bulb implies the decreasing current also in the circuit.



3. How is potentiometer used in appliances and devices?


Potentiometer is used as a variable resistor that can be adjusted from time to time. The variation of potentiometer is the control of brightness and volume in devices like phones and others.

VI. Generalization:




Based on the data, it is can be concluded that potentiometer really affects the current with its resistance value that can be manipulated. As the potentiometer is totally opened, current is zero causing to have no light in the bulb.