OBSTRONICS SYSTEM: BLOCK DIAGRAM

BLOCK DIAGRAM

The complete block diagram is shown in fig 2.2 and a transmitter position is shown in fig 2.1. The explanation of each block goes like this:

RF TRANSMITTER: The Radio Frequency Transmitter transmits the zone code to the receiving units. There are two zones in the present system: School Zone and Hospital Zone. Each Transmitter has carrying frequency of 144 MHz and data frequency range between 17, 19, 22 and 25. Transmitter #1 is set to data frequency of 17 and Transmitter #2 is for 19.

RF RECEIVER: The Radio Frequency Receiver receives the Zone Code transmitted by the Transmitter. According to the number of transmitter, here for Transmitter #1 & #2 respective output pins go high. The output is fed to directed opto-coupler for further processing.

BUFFER & DRIVER UNIT: This unit provides unit gain amplification to the received Zone Code signal and drives the relay for further feeding. The output of Zone Code signal is fed to Microcontroller chip as input and gets Speed Limit & Low Horn commands from it and drives the two more blocks.

MICROCONTROLLER CHIP: This is heart of this system. This takes Zone Code signal as input and generates four command signals for output purpose. The inherited software manipulates the inputted data and generates four command signals. Depends upon the Zone Code, it generates set of two command signals. If Zone Code is from School Zone Transmitter then the display message is generated and Speed Limit Command is outputted. Suppose Zone Code is from Hospital Zone Transmitter then respective display message is generated and Low Horn Command is outputted.

LCD DISPLAY: The Liquid Crystal Display shows the display messages generated by the Microcontroller chip, which is depending upon the Zone Code received.

VARIABLE POWER SOURCE: When Speed Limit Command is generated after certain delay by the Microcontroller chip, it is sent to this stage for reducing the speed. This stage actually lowers the supply voltage to the vehicle’s motor.

REDUCED POWER SOURCE: When Low Horn Command is generated after certain delay by the Microcontroller chip, it is sent to this stage for lowered horn sound. This stage actually lowers the supply voltage to the speaker, such that horn sound will be minimized.

POWER SUPPLY UNIT: As this stage has driver & relay stages, requires dual regulated power supply for working purpose. Specially designed +12 & +5 Volts regulated power supply is used to give proper working voltage to the whole section.
Fig1Obstronics System With_decrypted
FIG. 1 Obstronics system