In this project we will on/off the AC motor using TV remote . we are using RC5 standard of remote to control it. We are using Philips TV remote.
Its a low cost control system. We will press keys 1,2,3—- and will control devices and stepper motor. We are using TSOP1738 in this project. It works on 38 KHz. It give serial data at pin no 14(p3.3) of 89s51 microcontroller. We are using microcontroller 8051 which we studied in 8085 microprocessor. We can do programming of microcontroller to control in C or assembly or other language. We are doing programming in assembly because its easy.89s51 is Atmel company’s IC. Its also low cost IC
|Philips RC-5 Protocol|
The RC-5 code from Philips is possibly the most used protocol by hobbyists, probably because of the wide availability of cheap remote controls.
The protocol is well defined for different device types ensuring compatibility with your whole entertainment system. Lately Philips started using a new protocol called RC-6 which has more features.
- 5 bit address and 6 bit command length (7 command bits for RC5X)
- Bi-phase coding (aka Manchester coding)
- Carrier frequency of 36kHz
- Constant bit time of 1.778ms (64 cycles of 36 kHz)An ideal diode is like a light switch in your home. When the switch is closed, the circuit is completed; and the light turns on. An ideal diode & a typical diode characteristic would be:
Junction transistors consist of two junctions made from N-type and P-type semiconductor materials and are called bipolar transistors (two polarities). They have three connections emitter, base, and collector.
The forward biased base/emitter junction causes electrons to be attracted from the emitter area towards the base. Arriving in the base area, most of the negative electrons come under the influence of the more positive collector and are attracted by it. This is shown in the left hand drawing, where the base current plus collector current equals the emitter current. Alpha gain is collector current divided by emitter current, and is always less than 1. Beta gain is collector current divided by base current and can be fairly high number. Therefore, causing a small base current to flow makes a much larger collector current to flow. A small base current controls a large collector current. There is 0.6 volts across the base emitter junction, where it is forward biased (0.3 volts for germanium).