Project Report Topic Automatic Outdoor Umbrella.pdf

Using analog circuit knowledge obtained through this electronic course, we will design a circuit can detect humans, rain water, UV rays and control the motor to open and close an umbrell

HANOI UNIVERSITY OF SCIENCE AND TECHNOLOGY

-úûúû -

ELECTRONICS 1

PROJECT REPORT TOPIC:

Instructor: Dr Nguyen Canh Quang

Group 8 Class: CTTT Co dien tu 01 –

1 Nguyễn Hoàng Hà - 20185253

2 Đàm Minh Tuấn - 20185308

Hanoi, 01/2022

1

TABLE OF CONTENTS

I Introduction: 2

1 General information: 2

II Circuit Design 3

1 IR Sensor Circuit 3

2 UV Sensor Circuit 5

3 Rain sensor circuit: 6

4 Motor Controller 8

III Simulator circuit: 12

IV Physical Circuit 14

V Conclusion 15

I Introduction:

1 General information:

a Objective:

Our goal is to create an automatic outdoor umbrella Using analog circuit knowledge obtained through this electronic course, we will design a circuit can detect humans, rain water, UV rays and control the motor to open and close an umbrella

b Block diagram and Operation of Circuit:

3

1 IR Sensor Circuit

a IR sensor:

IR LED: An infrared light-emitting diode (IR LED) is a solid-state

light-e mitting (SSL) device that produces light in the infrared

band or range of the electromagnetic radiation spectrum IR LEDs

allow for cost-effective and efficient production of infrared light,

which is elec tromagnetic radiation in the 700 nm to 1mm range

Choosing a resistor connected to IR LED in series:

1.2V; I 20 ; Vcc=+5V

5 1.2 190

20 10

LED

LED

Vcc V

R

I

 Select: R ý1 220 to ensure that ILED is satisfied and protect the LED

IR Photodiode: An IR photodiode is an electrical component that converts light into

electricity The IR photodiode is used to detect the light rays

reflected by an IR LED

The IR photodiode is installed as a reverse bias (its cathode is

connected to +Vcc) If the photodiode is not exposed to light, the

resistance across it will be high, leading to I ý When the D 0

photodiode is exposed to light, the electrical resistance across the

diode decreases, in creasing the reverse current

b Potentiometer:

Potentiometer is an instrument for measuring an electromotive

force by balancing it against the potential difference produced

by passing a known current through a known variable

resistance Otherwise, it is also a variable resistor with a third

adjustable terminal The potential at the third terminal can be

adjusted to give any fraction of the potential across the ends

of the resistor

 Select the Potentiometer 10k connected to inverting input of Op-Amp in order to change value of the potential and adjust the sensitivity of the Op-Amp

c Operational Amplifier: LM358

The LM358 is a low-power dual operational amplifier integrated

circuit It can handle +3 V to +32 V DC supply and source up to 20

mA per channel In this part, it is used as a comparator

Circuit diagram:

Pin 1: Output voltage, channel 1 (C1)

Pin 3: Non-inverting input, C1

Pin 4: Ground

Pin 5: Non-inverting input, channel 2 (C2)

Pin 6: Inverting input, C2

Pin 7: Output voltage, C2

Pin 8: +Vcc

Parameters of LM358:

+ Using a single source from +3V to +32V or using a dual

source from +2V to +16V

+ Amplification gain from Ký0 to Ký100 dB

d Red-Led:

A red-led is used to signal that IR sensor detected humans

Choosing a resisor connected to the red-led in series:

1

2.2 ; V 3.8 ; 20

1

3.8 2.2 80

20 10

LED

R

I

 Select: R ý3 100 to ensure that ILED is satisfied and protect the LED

e Diagram circuit:

f Operation

IR LED always emitt infrared rays When people approach to the IR sensor, these rays are blocked and reflect Next, the IR photodiode receive the IR rays Until the received rays is great enough, there is a

5

reverse current I through the resistor D R Following that, the voltage of non-inverting input,2 V is equal to that of R , 2 V R 2

Comparation:

ø ù ø ù

ø ù ø ù

1 1

3.8 0

out out

Actually, because of temperature, load and type of Op-amp, Vout1ýVcc 1;1.5

In our condition, Vout1 ýVcc 1.2ý3.8V

 In the end of this stage, we get Vout1

2 UV Sensor Circuit

a UV sensor module: GUVA-S12SD

UV sensors measure the power or intensity of inc ident ultraviolet (UV)

radiation UV sensors are used for determining exposure to ultraviolet

radiation in laboratory or environmental settings They are transmitters that

respond to one type of energy signal by producing energy signals of a

different type

b Schematic

c Operation:

According to manufacturer, this module consists of an integrated and amplified circuit with an op-amp LM358 In out project, we connect Vout1 to pin 8 of the op-amp As a result, when operating, the output voltage of the sensor is:

2 3 1

1

k

The value of V is coressponding to UV intensity that D3 D receives, and 3 Vout 2 is ranging from 0V to

1

out

V

In our project, Vout2ý0;3.5V

3 Rain sensor circuit:

a Rain sensor: YL-83

The working principle of the YL-83 Rain sensor is very simple When

there is moist or wet are cover the space between two pole, the sensor

becomes a closed circuit

Rain and snow are quickly and accurately detected with the YL-83 Rain

Detector The YL-83 operates via droplet detection rather than by signal

level threshold

The YL-83 also features an analog Rain Signal for estimating rain

intensity Since this signal is proportional to the percentage of moist or wet

area on the sensor plate, rain intensity has a direct impact on the amplitude and variation of this analog signal

The YL-83 sensor is positioned at a 30° angle This design, together with the internal heating element, ensures that the surface dries quickly, an essential factor in calculating intensity

The sensor plate has minimum resistance of 20k (raining) and can reach to 400k (dry)

b Diagram circuit:

7

c Operational Amplifier: LM358

In this part, we use a op-amp LM358 to design an Adder and

Comparator circuit

LM358 can add the value of two input voltages, V+ at pin 3 and

V- at pin 2 then give the value of output, V at pin 1 out

Since, R8 ýR9ý R10ý R11ý 220 , Voutøpin 1ù ýVR7 Vout2

The input V+ at pin 5 is connected to the pin 1,

V pin ýV pin

The input V- at pin 6 is connected to Potentiometer, we use it to

adjust the value of V- and sensitivity of the comparation circuit

d Potentiometer:

Here we choose the Potentiometer 10K Ω which is connected to inverting input of Op-Amp so we can change value of the inverting input voltage voltage at pin 6

A red led is use to signal that the rain sensor is ON

Choosing a resistor connected to the led in series:

7 2.2 3.8 2.2

80

out

V pin

 Select: R ý12 100

f Operation

You can see the practical implementation of the LM358 Opamp adder circuit including two separate input, a sum of two input voltages ( VR7 and Vout2)

R

V ü V when it is rain

7

7

7

20,000 20, 000

R

sensor

R

7

7

7

400, 000 20, 000

R

sensor

( 1)

V pin ýV V

For comparation,

If :

�㕉 + (�㕝�㕖�㕛 5) > �㕉 2 (Voutøpin�㕝�㕖�㕛 6 7ùý Vccý5)=> V

ø 5ù ø 6ù

V pin üV pin => Voutøpin 7ùýVGND

We can change the value of Potentiometer so that the benchmark will change:

o VR increases => V- decreases => can detect humidity, light rain and low UV index

o VR decreases => V- increases => can detect heavy rain and high UV index

In reality, because of temperature, load and type of Op-amp, the real Voutøpin 7ù ýVcc 1 ;1.5V V

In our situation, Voutøpin 7ù ýVcc 1.2ý3.8V

4 Motor Controller

a Transistor BC547:

Because the relay only work when the source is connected or cut off, so we need something to turn on-off its input That why we are going to use a transistor to do the work The transistor have 3 terminals :

Collector, base and emitter

9

For this transistor to work as a switch, we need it to operate in the saturation region First we need to calculate the key parameter to find our transistor

5 0.09 0.1403 140.3 0.5* 0.5*70

CE

C

L

Vcc V

R

To make sure the transistor operate in saturation region, we need an resistor R connected in series with 13

the transistor

We can calculate the resistance of R as follow: 13

ø ù

min 6 13

140.3 110 3.8 0.6 0.7

1.9 140.3 /110

C B

B

I I

I

 Select R13ý1k to ensure that the transistor works in saturation region

b Diode: 1N4007

Diode D6 is used to prevent that the current from capacitor C2

flows back to the op-amp U3 when there is no power supply

In the working state, Cathode of diodes (D7 & D8) connected to

+12V voltage, so it is reverse bias But when the circuit moves

from on to off => Diode is used to protect transistor

The voltage of coil can calculated as follow :

coil

di

dt ý When the source is disconnected, the current drop to zero => Vcoil

is large and produce a large induced current

=> VCE ýVcc Vcoil þVCEmax => Transistor can be broken down

Because Diod is in forwarded bias, it can terminate the induced current from the coil of relay Hence, it protect the transistor

 Select: 1N4007 because of the high maximum voltage (Vmax=1000V)

c Relay :

A relay is an electrically operated switch It consists of a set of input terminals for a single or multiple control signals, and a set of operating contact terminals Relay is consists of a switch and a coil When a

current flows through the coil of relay, the coil will attract the contact to closed When the current stop goes through the coil, the magnetic field in the coil change direction and push the contact open

In our project, to control the direction of the DC motor, we decided to used 2 relays in parallel These two relays will always operate in the same status This could help in changing the direction of the current going through the motor

Because the relays is connected with the 5V source, we design two 5V relay in parallel.And the current

Ic from transistor will goes through both relays

On the other side , The NO ( Normally Opened) terminal of Relay 1 is connected to the Limit Switch at Fully-Open Position.The NC ( Normally closed) terminal of Relay 2 is connected to the Limit Switch at Closed Position

d.Operation

When the sensor system detect rain or UV,

V = V (opamp) = 3.5V in out

The transistor is on an and a current goes through the Collector and Emitter terminal

This current will active Relay 1 and Relay 2 at the same time

There are two cases :

* If the umbrella is in closed position, the Limit switch 2 is opened, the current will pass the motor in the direction from Limit switch 1 to Relay 1and to Relay 2 The motor will rotate in forward direction

* If the umbrella is fully - opened, the limit switch 1 is opened and the motor stops

When the sensor system does not receive any signal

Vin = Vout(opamp) = 0V

The transistor if off and act as an open circuit

No current pass through relay

11

* If the umbrella is fully-opened The Limit switch 1 is opened The current from the source will goes through the Limit switch 2 -> Relay 2 -> Relay 1 Hence, the motor rotates in reverse direction

* If the umbrella is closed The Limit switch 2 is opened and the motor stops

III Simulator circuit:

13

List of equipment

IR Sensor

Rain Sensor

YL-83 rain sensor panel 1

Motor Controller

IV Physical Circuit

15

V Conclusion

In conclusion, after a long progress, we finally finish the circuit design and start working on circuit assembly

We have been developing our project every week

By accumulating knowledge from Electronics 1 lessons and with the help of Dr Nguyen Canh Quang, we could finally achieve our goal

This project is the best chance of us to practice and learn many new skills to develop an electronic project Understand the characteristic diagrams of our project‘s components

Know how to use opamp as adder, comparator

Know how to use BJT to drive relay as a switch

Know how to chose the right requirement data for each component

Fluently in using Proteus to make an simulation circuit

Improve our logic design and mechanism design

Team working

With the practicle result of the project, we are very proud of our well optimized and useful product can bring to the user convenient Also we are very pleased with the knowledge and skill we accumulated from this project

With the limit of skills as students, there are unavoidable mistakes We are very hopeful that you give us some recommend and feedback on our project

THANK YOU!