CAN Based accident avoidance system Project Report

It is an embedded system based application. The main design  an aspect of CAN Based accident avoidance system project is to avoid the accidents by using CAN protocol. This Project describes a design of effective accident avoidance system that detects an automotive / vehicle / car condition in traveling with the help of ultrasonic sensors and this signal can be used to switch off the apply emergency hand brake or disc brake  with the help of which accident can be avoided.   

                                        In Present scenario maximum number of deaths is due to accidents main reason for accidents are due to negligence of drivers. In order to solve this problem we use can based accident avoidance system which will collect traffic information surrounding moving car and inform to driver in the form of alarm.

download CAN Based accident avoidance system 

Wireless Mobile Battery Charger Circuit

Emerging technologies are making our life simpler these days. With the introduction of mobile phones, life has changed rapidly. This is a dream of radio engineering. Mobile phones merged land line telephone systems. These days, many advancements in the mobile phones were introduced. These advancements provide many services such as text, internet etc. But although there are many advancements in the technology, we still rely on the wired battery chargers. Each phone will have its own designed battery charger. Thus the battery chargers are required to carry everywhere to keep the battery backup. Now just think of a battery charger that charges your mobile automatically. When you sit for tea and place your mobile on the table, it simply charges your mobile. This article explains a simple wireless battery charger circuit that charges you mobile when placed near the transmitter. This circuit may be used as wireless power transfer circuit, wireless mobile charger circuit, wireless battery charger circuit, etc.

Wireless Battery Charger Circuit Principle:

This circuit mainly works on the principle of mutual inductance. Power is transferred from transmitter to the receiver wirelessly based on the principle of “mutual induction”.

Inductance is the property of the conductor, in which the current flowing in a conductor induces a voltage or electromotive force in it or in another nearby conductor. There are two types inductance.1)Self inductance, 2)Mutual Inductance.

“Self inductance” is the phenomena in which when the current is passing in one conductor, an emf is introduced in another coil.

“Mutual inductance” is the phenomena in which, when a current carrying conductor is placed near another conductor voltage is induced in that conductor. This is because, as the current is flowing in the conductor, a magnetic flux is induced in it. This induced magnetic flux links with another conductor. Thus this flux induces voltage in the second conductor.

Wireless Power Transfer Circuit Diagram:

Wireless Mobile Charger Circuit Diagram

Wireless Mobile Charger Circuit Design: 

Wireless battery charger circuit design is very simple and easy. These circuits require only resistors, capacitors, diodes, Voltage regulator, copper coils and Transformer.

In our Wireless battery charger, we use two circuits. The first circuit is used to produce voltage wirelessly. Initially, transformer is used to step down the voltage from 230 V to 12V. This step-down voltage is applied to the diode. The 1N4007 diode is used to allow the voltage to flow in one direction only. This is then passed to the 7812 voltage regulator. The output of this regulator is a 12V DC voltage. Two capacitors are placed before and after the voltage regulator to eliminate the ripples. Next it is connected to the oscillator circuit. It produces a frequency of 10 MHz. The values of resistors and capacitors are calculated in such a way that it produces oscillations of 10MHz. Then it is fed to the inductor. Inductor is used to induce the voltage in the second circuit.

In the second circuit, another inductor is used for the mutual inductance. A voltage multiplier circuit is used after the inductor. It is then connected to the voltage regulator 7805.7805 and 7812 are family of 78XX integrated circuit. It produces fixed voltage at the output. 78 represents series and XX represents the output voltage. At the output of the regulator a capacitor is connected. Thus output is connected to the battery.

How to operate this Wireless Power Transfer Circuit?

• Initially, connect the circuit as shown in the circuit diagram.
• Now connect Ac voltage to the transformer.
• Switch on the supply.
• Connect the battery charger at the output of the circuit.
• Make sure that AC and DC sources should not have common connections.
• You can observe the battery charging at the output.

Wireless Battery Charger Circuit Advantages:

• Usage of separate charger is eliminated.
• Phone can be charged anywhere and anytime.
• It does not require wire for charging.
• Easier than plug into power cable. 

Wireless Power Transfer Circuit Applications:

• Wireless chargers can be used to charge mobiles, camera batteries, Bluetooth headsets etc.
• This can also be used in applications like car battery charger with little modification. Go to Simple Car Battery Charger Circuit post for more information.
• This can also be used in medical devices.

Limitations of the Circuit: 

• Power is somewhat wasted due to mutual induction.
• It will work for very short distances only. If you want to use it for long distances, then the number of inductor turns should be high.

TV Transmitter Circuit

Have you ever thought of transmitting audio and video signals? Here is the simple circuit that amplifies and transmits audio, video signals. These are transmitted in very high frequency band (VHF).

TV Transmitter Circuit Principle:

The main principle of this circuit is to transmit the audio and video signals. Here audio signals are frequency modulated and video signals are PAL modulated. These modulated signals are applied for the antenna.

Also get an idea about How FM Radio Transmitter Circuit Works?

TV Transmitter Circuit Diagram:

TV Transmitter Circuit Diagram

Circuit Components:

The circuit consists of following components:

• BC547 transistor.
• Signal diode (1N4148).
• Resistors.
• Capacitors.
• Radio frequency transformer.
• Antenna.
• Variable capacitor.
• Variable resistor.

Read this interesting concept: TV Remote Jammer Circuit using 555 Timer IC

TV Transmitter Circuit Design:

The TV transmitter circuit design is explained below.

The audio signal is applied to the base of the transistor through a resistor and capacitor of 10Kohms and 10uf respectively. Emitter of the transistor is connected to the radio frequency transformer. The audio signal here is pre-amplified by the transistor.

Radio frequency transformers are used for maximum power transfer. They have two windings Primary and secondary. The voltage is applied at the primary winding and due to mutual inductance some voltage is induced in the secondary winding of the transformer. Hence voltage can be transferred from one circuit to another circuit. Here in this circuit, a transformer with an inbuilt capacitor is used.

Signal diode is a diode which allows the current to flow only in one direction. They pass small currents upto 100mA and process the information in the electrical signals. They are used widely in signal processing. Here signal diode is used for video modulation.

The audio input is connected to the base of the transistor through a resistor and capacitor in series. A  LC tank circuit is connected to the collector terminal of the transistor .This tank circuit produces the carrier frequency for modulation .The tank circuit consists of a variable capacitor and a resistor in parallel.

Video input signal is applied to the transistor through the variable resistor of 1kohms. It is fed to the pot through a capacitor of 0.1uf and a signal diode in parallel to it.

The modulated signals are fed to the antenna. Antenna is required to transmit the signal. Antenna takes the electrical signal and converts them into an electromagnetic radiation. This radiation is emitted by the antenna.

How to Operate TV Transmitter Circuit?

• Initially connect the circuit as shown in the circuit diagram.
• Apply a voltage of 12v through a battery to the circuit.
• Now the audio input is applied to the base of the transistor.
• The transistor pre amplifies the audio signal and is applied to the RF transformer.
• Video signal is applied at the input of the video.
• Here RF transformer  applies the audio signals to the transistor Q2.
• The transistor Q2 modulates the audio , video signals and transmits them to the antenna.
• The carrier frequency required for modulation is produced by the tank circuit.
• Thus the modulated wave is transmitted by the antenna and this circuit works with VHF band somewhat between 50-210 MHZ.

TV Transmitter Circuit Applications:

• This is used in broadcasting applications.
• This circuit can transmit audio and video signals from DVD, videogames, etc.
• The circuit can be used in surveillance cameras.

Limitations of the Circuit:

• The transmitter circuit is compatible with PALB and PALG systems.
• To get optimum performance, one should adjust the value of C8.

FM Remote Encoder/Decoder Circuit

We have already studied how to control the home appliances using RF communication in the post RF Remote Control Circuit for Home Appliances. Now let us see how to design FM remote encoder and decoder circuit using RF600E and RF600D ICs. This pair of encoder and decoder ICs establishes the communication with high level security. The operating voltage of these ICs is from 2V to 6.6V DC.

This system uses FM (Frequency Modulation) for transmission. If you press any push button then corresponding code is generated at transmission section. Here encoder is used to convert parallel data to serial. This serial data is given to the FM Tx module to transmit. FM Rx module receives this serial data and fed to the decoder to produce the corresponding output.

FM Remote Encoder and Decoder Circuit Diagram:

Transmitter Section:

FM Remote Encoder and Decoder Circuit – Transmitter Section

Circuit Components:

• RF600E encoder
• FM Transmitter module
• 4 push buttons
• Bc848 Transistor
• Led
•  Resistors – 2.2k, 10k

Receiver Section:

FM Remote Encoder and Decoder Circuit – Receiver Section

Circuit Components:

• RF600D Decoder
• FM Receiver module
• Slide switch
• Push button
• Red LED
• Resistors – 1k(2), 15k, 22k

FM Remote Encoder/Decoder Circuit Design:

The circuit mainly consists of two sections, one is Transmitter section used t transmit the remote data and other is Receiver section used to receive the data.

Transmitter Section:

This section consists of RF600E encoder, FM transmitter module, four switches and LED. Four push buttons are used to generate the parallel data. If you press any push button, then corresponding code is generated at the 6^th pin of encoder. Here the LED which is connected to the 7^th pin of encoder is used for indicating the signal transmission.

RF600E Encoder:

This pair of encoder and decoder ICs uses balanced Manchestar encoded data protocol for transmission. This encoder IC requires just fewer components to use it as a transmitter. The transmission is automatic there is no need of human intervention.

The data format includes a pre-amble, header, encrypted data followed by CRC bit. Here the packet size is 67 bits.

Low Battery Indication:

This encoder IC reads the battery status for each operation. If the voltage is below 3.8 volts then flag bit is transmitted to the decoder IC.

Pin Configuration:

Pin No.	Name	Description
1	S0	Input data pin0
2	S1	Input data pin1
3	S2	Input data pin2
4	S3	Input data pin3
5	Vss	Ground reference connection
6	OP	Data output pin
7	LED	Cathode connection for driving LED during the transmission
8	Vcc	Supply voltage pin

Receiver Section:

The receiver section consists of RF600D decoder and its associated components. Pins 17, 18, 1 and 2 are the digital output pins corresponding to the input switches. If you press any push button, then the corresponding pin at decoder becomes low. Here SPDT switch is used to select latching or memory digital function. The learn switch is used to enter the decoder IC into the “learn mode”.

RF600D Decoder:

In this RF chipset, protocol data is sent serially as a stream of ASCII characters with a baud rate of 9600 bits per second. While coming to the frame format 8 data bits with one stop bit.

Pin Configuration:

Pin No.	Name	Input/Output	Description
1	OP3	Out	Data output pin
2	OP4	Out	Data output pin
3	LB	Out	Pin goes low, when battery is low
4	Vcc	In	Supply voltage pin
5	Vss	In	Ground pin
6	ECS	Out	Connected to EEPROM CS pin
7	ECLK	Out	Connected to EEPROM CLK pin
8	EDAT	I/0	connected to EEPROM DATA PIN
9	IN	In	Data input
10	LRN	In	learn/erase switch and status LED drive
11	SD1	Out	serial data output
12	LKIN	In	Option Link Input for Momentary or Latched outputs
13	SLEEP	In	1 = Run, 0 = Sleep Mode
14	Vcc	In	Positive supply voltage pin
15	Unused	N/A	no connection
16	Unused	N/A	no connection
17	OP1	Out	Data output pin
18	OP2	Out	Data output pin

How to Operate FM Remote Encoder and Decoder Circuit?

1. Give the connections as per the circuit diagram.
2. Connect the LED’s at the decoder outputs.
3. Apply 5V supply to the both transmitter and receiver sections.
4. Initially all the LED’s will glow.
5. Now press the first button at transmitter section, you can observe that first LED will off at decoder section. In the same way for each switch at transmitter the corresponding LED at receiver will off.
6. Switch off the power supply for both transmitter and receiver sections.

FM Remote Encoder/Decoder Circuit Advantages:

1. Stand alone operation
2. LED indication of signal transmission
3. Battery low indication
4. Manchester modulation
5. Sleep mode.

FM Remote Encoder/Decoder Circuit Applications:

• Used in general purpose Remote control applications
• Used in burglar alarm systems
• used in automotive systems
• Used in Electronic door locks

Circuit Limitation:

• This circuit is theoretical and may require some practical changes.