Cordless power controller
Introduction:
We live in a world of automation and full of facilities only because of
technology. In this world we have become so much addicted to technology so
that we would rarely try to turn on a television ourselves rather than searching
for the missing remote control for turning on the television.
Controlling electronic devices and domestic appliances using a remote
control is an attractive facility provided in the present consumer electronics
products. This product CPC (cordless power controller) is essentially a remote
control implemented with the help of a cordless phone. This makes it possible to
control lights, fans and other appliances of our home using our cordless phone.
This in fact eliminates the need of another remote controller in our home.
The CPC is connected between the receiver and the telephone lines so
that the signals at the input port of CPC will be same as from ordinary telephone
that will be in accordance with the conventional DOT standards.
The working of the CPC can be summarized as below
1. On reset, CPC would be in the telephone mode. Power control mode
(PCM) only after dialing a particular code. . After the code
has been entered, CPC switches to the power control mode. The
indicator and the tone generator tell us that the device has been
selected. And the relay disconnects telephone from the lines.
2. In the PCM, we can select different devices by dialing appropriate
codes for each (For eg.1 for bulb,2 for fan ) etc.
3. After selecting a device we can control the ON/OFF state of the device
by entering a different key (For eg. 3).
4. If the device selected is fan, we can con troll the speed of it by using
two dedicated switches, for increasing and decreasing the speed
respectively.
5. The mode changes automatically to telephone when the phone is
disconnected. Thus the device works in two modes namely
7
1. Power control mode
2. Telephone mode
The firing pulses for the TRIAC are generated by the µ-controller. The
phase of the firing pulse can be varied and hence the firing angle of the TRIAC.
By varying the firing angle we can control the brightness of the lamp, speed of
the fan etc. Isolation can be given by using the pulse transformer, at the
triggering side. The entire software for micro-controller is stored in an EPROM.
The product will be very useful for bedridden patients, handicapped
individuals and even lazy people!!!¦

Full report with all the details:

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