Circuits of Infra Red Sensor

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Photodioda as removing the transmitter beam infra red with the pulsation frequency 5KHz, then the pulsation will be reflection by reflector in front of it. and received by the phototransistor as the receiver. The detected object is located between the transmitter-receiver with a reflector.

Circuit on the left is the transmitter modulation circuit that produces infrared 5KHz throbbing. On the right side is the receiver circuit, there is a resonance tuned amplifier. Band width it can control so the receiver circuit can catch the beat of the transmitter modulation 5Khz. Bandwidth control is also working to reduce the sensitivity of the effect of light in the surrounding areas.

Rangkaian Sensor Parkir Mobil

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This is circuit can be used for sensing the distance between the rear bumper of the car and any obstacle behind the car. The distance can be understood from the combination of the LEDs (D5 to D7) glowing. At 25cm D7 will glow, at 20 cm D7&D6 will glow and at 5cm D7, D6 and D5 will glow. When the obstacle is beyond 25 cm none of the above LEDs will glow.

Skema rangkaian receiver sensor parkir mobil

Skema rangkaian transmitter sensor parkir mobil

Note:

• D1 & D2 must be mounted close (~2cm)
• D1 can be a general purpose IR LED.
• D2 can be general purpose IR photo diode with sun filter.
• Transmitter as well as receiver can be powered from the car battery.
• For proper working of the circuit, some trial and error is needed with the position of D1 and D2 on the dash board.

Two ICs are used in the circuit. The IC1 (NE555) is wired as an astable multivibrator for driving the IR Diode D1 to emit IR pulses. The operating frequency of the transmitter is set to be 120Hz.The IR pulses transmitted by D1 will be reflected by the obstacle and received by the D2 (IR photo diode).The received signal will be amplified by IC2a.The peak of the amplified signal will be detected by the diode D4 and capacitor C4.R5 and R6 compensates the forward voltage drop of D4.The output voltage of the peak detector will be proportional to the distance between car’s bumper and obstacle. The output of peak detector is given to the inputs of the other three comparators IC2b,IC2c and IC2d inside the IC2(LM324).The comparators switch the status LEDs according to the input voltage their inverting inputs and reference voltages at their non inverting inputs. Resistances R7 to R10 are used to set the reference voltages for the comparators.

Lay out IC LM324

Features

Internally frequency compensated for unity gain
Large DC voltage gain 100 dB
Wide bandwidth (unity gain) 1 MHz (temperature compensated)
Wide power supply range:Single supply 3V to 32V or dual supplies ±1.5V to ±16V
Very low supply current drain (700 μA)—essentially
independent of supply voltage
Low input biasing current 45 nA (temperature compensated)
Low input offset voltage 2 mV and offset current: 5 nA
Input common-mode voltage range includes ground
Differential input voltage range equal to the power supply voltage
Large output voltage swing 0V to V+ − 1.5V.
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Sensor Warna TCS230.

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Sensor Warna TCS230

TCS230 color sensor is a converter IC to the frequency of light colors. There are two main components of this IC makers, namely photodioda and current to frequency converters. Each color can be drawn from the basic colors. To light, color is the color of the basic constituent Red, Green and Blue, or better known as RGB (Red-Green-Blue).

Photodiode on IC TCS230 array arranged in a 8x8 configuration: 16 Photodiode for red menfilter, 16 Photodiode for the green filter, 16 Photodiode for the blue color filter, and unfiltered Photodiode 16. Photodiode groups which will be used can be arranged through the leg selector S2 and S3.

Gambar Sensor Warna TCS230

sample color and composition RGB 8-bit scale.

Table Combination pin function S2 and S3

Photodiode will issue the amount of current is proportional to the level of the basic colors of light that happened. This current is then converted into a signal box with a frequency proportional to the amount of current. Output frequency can be scaled by adjusting the leg selector S0 and S1.

Table Output scaling

Thus, programs that we need to get the RGB composition is a frequency counter program. There are two typical ways to calculate the frequency. The first way: We create a timer berperiode 1 second, and during that period we count how many times a wave box.

in the picture above
1 second place in 1000 wave means the frequency is 1000Hz or 1khz

The second way: We compute how much a period of one wave, then look for the frequency by using the formula

• F=1/T

1 full-wave mean period 1mS, frequency: 1/1mS = 1000Hz or 1khz

PENGERTIAN DAN JENIS SENSOR

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Sensor adalah peralatan yang digunakan untuk merubah suatu besaran fisik menjadi besaran listrik sehingga dapat dianalisa dengan rangkaian listrik tertentu. Hampir seluruh peralatan elektronik yang ada mempunyai sensor didalamnya.

Pada saat ini, sensor tersebut telah dibuat dengan ukuran sangat kecil dengan orde nanometer. Ukuran yang sangat kecil ini sangat memudahkan pemakaian dan menghemat energi.

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JENIS SENSOR

Sensor Fisika

Sensor fisika mendeteksi besaran suatu besaran berdasarkan hukum-hukum fisika. Contoh sensor fisika adalah sensor cahaya, sensor suara, sensor gaya, sensor kecepatan, dan sensor suhu.

Sensor Kimia

Sensor kimia mendeteksi jumlah suatu zat kimia dengan cara mengubah besaran kimia menjadi besaran listrik. Biasanya melibatkan beberapa reaksi kimia. Contoh sensor kimia adalah sensor pH, sensor oksigen,sensor ledakan, dan sensor gas.

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Sensor Cahaya

Sensor cahaya adalah alat yang digunakan untuk merubah besaran cahaya menjadi besaran listrik. Prinsip kerja dari alat ini adalah mengubah energi dari foton menjadi Elektron. Idealnya satu foton dapat membangkitkan satu elektron. Sensor cahaya sangat luas penggunaannya, salah satu yang paling terkenal adalah LDR (Light dependent resistor)

Prinsip kerja dari LDR ini adalah Resistansi LDR akan berubah seiring dengan perubahan intensitas cahaya yang mengenainya. Dalam keadaan gelap resistansi LDR sekitar 10MΩ dan dalam keadaan terang sebesar 1KΩ atau kurang. LDR terbuat dari bahan semikonduktor seperti kadmium sulfida. Dengan bahan ini energi dari cahaya yang jatuh menyebabkan lebih banyak muatan yang dilepas atau arus listrik meningkat. Artinya resistansi bahan telah mengalami penurunan.

Sensor Cahaya LDR

LDR digunakan untuk mengubah energi cahaya menjadi energi listrik. Saklar cahaya otomatis dan alarm pencuri adalah beberapa contoh alat yang menggunakan LDR. Akan tetapi karena responsnya terhadap cahaya cukup lambat, LDR tidak digunakan pada situasi dimana intesitas cahaya berubah secara drastis.

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Sensor Suara

Sensor suara adalah sebuah alat yang mampu merubah gelombang Sinusioda suara menjadi gelombang sinus energi listrik. Sensor suara berkerja berdasarkan besar/kecilnya kekuatan gelombang suara yang mengenai membran sensor yang menyebabkan bergeraknya membran sensor yang juga terdapat sebuah kumparan kecil di balik membran tadi naik & turun. Oleh karena kumparan tersebut sebenarnya adalah ibarat sebuah pisau berlubang-lubang, maka pada saat ia bergerak naik-turun, ia juga telah membuat gelombng magnet yang mengalir melewatinya terpotong-potong. Kecepatan gerak kumparan menentukan kuat-lemahnya gelombang listrik yang dihasilkannya.

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Sensor Suhu

Sensor suhu adalah alat yang digunakan untuk merubah besaran panas menjadi besaran listrik yang dapat dengan mudah dianalisis besarnya. Cara yang palin mudah Untuk mendeteksi suhu adalah dengan menggunakan sensor suhu LM 35 yang dapat dikalibrasikan langsung dalam C, LM 35 ini difungsikan sebagai basic temperature sensor.

LM 35 sensor suhu

Vout dari LM 35 ini dalam suhu kamar (25^oC) tranduser ini mampu mengeluarkan tegangan 250mV dan 1,5V pada suhu 150^oC dengan kenaikan sebesar 10mV/^oC.

Car Parking Sensor circuit Using Infra-Red LED

type='html'>This circuit can be used for an assist in parking the car near the garage wall backing up Pls. LED D7 illuminates Pls bumper-wall distance is about 20 cm., D7 + D6 illuminate at about 10 cm. and D7 + D6 + D5 at about 6 cm. In this manner you are alerted Pls approaching too close to the wall.

Car Parking Sensor circuit

All distances mentioned before can vary, depending on infra-red transmitting and receiving LEDs used and are mostly affected by the color of the reflecting surface. Black surfaces lower greatly the device sensitivity. Obviously, you can use this circuit in other applications like liquids level detection, proximity devices etc.

Note:

• The infra-red Photo Diode D2, should be of the type incorporating an optical sunlight filter: these components appear in black plastic cases. Some of them resemble TO92 transistors: in this case, please note that the sensitive surface is the curved, not the flat one.
• Avoid sun or artificial light hitting directly D1 & D2.
• If your car has black bumpers, you can line-up the infra-red diodes with the (mostly white) license or number plate.
• It is wiser to place all the circuitry near the infra-red LEDs in a small box. The 3 signaling LEDs can be placed far from the main box at an height making them well visible by the car driver.
• The best setup is obtained bringing D2 nearer to D1 (without a reflecting object) until D5 illuminates; then moving it a bit until D5 is clearly off. Usually D1-D2 optimum distance lies in the range 1.5-3 cm.

List Component of Car Parking Sensor circuit:

R1 : 10K
R2,R5,R6,R9 : 1K
R3 : 33R
R4,R11 : 1M
R7 : 4K7
R8 : 1K5
R10,R12-R14 : 1K
C1,C4 : 1µF/63V
C2 : 47pF
C3,C5 : 100µF
D1 : Infra-red LED
D2 : Infra-red Photo Diode (see Notes)
D3,D4 : 1N4148
D5-7 : LEDs (Any color and size)
IC1 : NE555
IC2 : LM324
IC3 : LM7812