4.11 Motor A DC motor is an electrical machine which converts electrical energy into mechanical energy. A magnetic field is generated by the current carrying conductor and when this system is placed in external magnetic field then the force is exerted which is proportional to the strength of the external magnetic field and to the current in the conductor, then motor will rotate. If the direction of current is reversed then the direction of rotation of motor will also reverse. The speed of DC motor can be controlled by the variable supply voltage or by changing the strength of current. Small DC motors are used in toys, tools, and appliances. Larger DC motors are used in propulsion of electric vehicles, in drives for steel rolling mills, elevator …show more content…
The MAX232 is a dual receiver/driver and it converts the TX, RX, CTS and RTS signals. The drivers provide RS-232 voltage level outputs (approx. ± 7.5 V) from a single + 5 V supply via on-chip charge pumps and external capacitors. The receivers reduce RS-232 inputs (which may be as high as ± 25 V), to standard 5 V TTL levels. These receivers have a typical hysteresis of 0.5 V and a typical threshold of 1.3 V. Figure 4.16: Pin Diagram of MAX232 4.13 RS232 Interface In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DCE (Data Circuit-terminating Equipment) and a DTE (Data Terminal Equipment). It is use to connect the computer serial port to the electronics component like data storage, printers, mice, un-interruptible power supplies, and other peripheral devices. The standard defines the meaning of signals, the electrical characteristics and timing of signals, and pin out of connectors and the physical size. Figure 4.17: RS232 4.14 Motor