1. ROBOT CONTROLLER( H- bridge) REMOTE UPPER PART 1a) CONTAINS 4 RELAYS ,,EACH RELAY CONSISITS OF 5 PINS . 2 PINS ARE NC (normally closed) AND NO (normally open) ,while 3 pins on the other side denote commom or change over ( at center) and the two pins are of coil . . IC is also placed which is used for giving output to the switches only high or low and converting low current to high current as we learn in case of transistors REMOTE LOWER PART 1b) CONSISTS OF IC LOWER PART CONNECTED TO THE 4 SWITCHES. 4 SWITCHES CONTAINS THERE OWN RESISTOR TO RESIST THE HIGH CURRENT FLOW. 2) This remote is handmade H-bridge remote to know about the internal procedure inside each switch, but know in markets SPST switches are available in which all type of transistor ,resistors,diodes etc are present internally.

4. ALL 4 COLOURS OF WIRES ARE COMING FROM RELAY COMMON (CENTRE ) PART ,WHICH FURTHER MAKE CONNECTION WITH THE MOTOR OF THE ROBOT.

6. 1) RELAYS

7. IMAGES OF RELAY

8. . NO AND NC ARE NAMED SO ,BECAUSE OF THE POSITION OF THE PIN WITH RESPECT TO COIL

9. Protection of a relay using diode Transistors and ICs must be protected from the brief high voltage produced when a relay coil is switched off. The diagram shows how a signal diode (eg 1N4148) is connected 'backwards' across the relay coil to provide this protection. Current flowing through a relay coil creates a magnetic field which collapses suddenly when the current is switched off. The sudden collapse of the magnetic field induces a brief high voltage across the relay coil which is very likely to damage transistors and ICs. The protection diode allows the induced voltage to drive a brief current through the coil (and diode) so the magnetic field dies away quickly rather than instantly. This prevents the induced voltage becoming high enough to cause damage to transistors and ICs.

12. Integrated circuits can be classified into three types they are, (1).Analog. (2).Digital. (3).Mixed signal. Analog ICs, such as sensors, power management circuits, and operational amplifiers, work by processing continuous signals. They perform functions like amplification, active filtering, de modulation, mixing, etc

13. Digital integrated circuits can contain anything from one to millions of logic gates, multiplexers(A device that can interleave two or more activities), and other circuits in a few square millimeters. The small size of these circuits allows high speed, low power dissipation, and reduced manufacturing cost compared with board-level integration. ICs can also combine analog and digital circuits on a single chip to create functions such as Ac/Dc converters and Dc/Ac converters. Such circuits offer smaller size and lower cost.