mini project help,..

Thread Starter

raks_universe

Joined Mar 15, 2009
67
Hi guys,.,.

I have to do my mini project in electronic circuits,.,.,,

I selected my topic as "Remote controlling of lights and Fan",.,.,.

pls help me with "appropriate" circuit ,.,.,.,:)
 

retched

Joined Dec 5, 2009
5,207
You have fans in India? lucky!

Ok, you want to remotely operate relays that will turn lights and/or fans on and off?

What wireless technology did you want to use for this feat? And also, Where do you want to locate the receivers? Do you want to replace the wall switches with the wireless receivers? or do you want them installed with the fan or light?
 

Thread Starter

raks_universe

Joined Mar 15, 2009
67
You have fans in India? lucky!

What wireless technology did you want to use for this feat? And also, Where do you want to locate the receivers? Do you want to replace the wall switches with the wireless receivers? or do you want them installed with the fan or light?
Sir,
I am oly beginner in electronics,.,.I hav to submit this project,.,

My receiver should be in lights and fan,.,.,.,

By pressing a button ,i should turn on the light,.,.and by pressing an another button in the "same" remote,i hav to switch on the Fan,.,.,


This is my idea on my project,.,.,.

Pls help me with "entire" circuit,.,.,.pls...
 

retched

Joined Dec 5, 2009
5,207
Do you have to redesign a transmitter and receiver from scratch? Or can you use pre-built transmitters and receivers?
 

Thread Starter

raks_universe

Joined Mar 15, 2009
67
Do you have to redesign a transmitter and receiver from scratch? Or can you use pre-built transmitters and receivers?
no sir,.,.,i need redesigned circuit (pre-built circuit ll not be accepted in my college) ,.,.it also help me to gain some practical knowledge ....

Pls provide me with redesigned elementary circuit(not so complicated),.,,pls,.,
 

retched

Joined Dec 5, 2009
5,207
RF is not my specialty. I can design using existing components, but designing these components from scratch is beyond my level of knowledge.

Also, you are going to have to choose a few things before a design can start.

What frequency do you want to transmit and recieve to operate these devices and, are you willing to use light rather than ultrasonic for the device? How much power will the relays be handling and what power source do you want to use to power the circuit itsself?

I understand that the lamp and fan will most likely be powered from the wall, but will the remote control circuits be powered by battery or via a transformer?
 

elex09

Joined Mar 17, 2010
39
hi,

im using a 12V SPDT relay to turn ON a fan in energized condition...I have supplied the 12V to relay from 7812 regulator and have connected a 12V,0.18A fan to the NO contact of relay...on switching on power supply i could hear a sound which sounds like relay switching but fan did not work..on checking the 7812 o/p on multimeter I observed just about 8.4-8.6 volts instead of 11.8 or 12V..but how is the relay switching happening off that voltage?
also do i need to connect a 12V battery to NO contact and then the fan to it or will the fan work from the 12V supply to the relay?

pls reply asap..
 

retched

Joined Dec 5, 2009
5,207
Even though you are hijacking the thread......

..If you read the datasheet for your relay, you will find that it will energize much lower than the printed rating. The whole point of using a relay is because you have two different power sources. If you are running the fan and the relay off the same 12v, you dont need the relay. You just need a switch.
 

elex09

Joined Mar 17, 2010
39
thanks for the reply retched...and sorry for hijacking..

so u are saying that i must give a different power supply to the fan from the relay...
so the flow will be: 12v to relay from 7812, NO of relay to battery , and battery to fan, then fan to ground..

am i right here or have i goofed up??
 

retched

Joined Dec 5, 2009
5,207
Yes.. Its fine.. Im just wondering why you need the relay?

positive terminal from battery to switch, switch to positive on fan.
Neg terminal from battery to neg on fan.

If the fan was 120vAC and you wanted to switch it with 12vDC you would use a relay.

The 120AC to the NO contact on the relay then the common from the relay to the fan
Then Connect the neutral of the fan to the neutral 120AC.
Then the +12vDC from the battery to a button then to the +relay coil
The (gnd) from the battery tp the -relay coil.

That way when you activate the 12vDC button, the relay energizes, and closes the 120vAC circuit, operating the fan.

If everything is 12vDC, skip the relay all together. Just use a button or switch.
 

Thread Starter

raks_universe

Joined Mar 15, 2009
67
need immediate help..... pls help me with circuit of "remote controlling of lights and fans"...

Pls Pls.....:confused:
 
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R!f@@

Joined Apr 2, 2009
9,918
Further more I need to know what You know about remote controls and why you chose this.
RF and Infra, what ever the type may be these ckts are not simple and needs atleast micro processor to work properly.
uPC is necessary to modulate the carrier for long range transmission and also to guarantee proper operation. Using more than one channel complicates things a lot since the transmitter should use more than one modulated information to operate the receiver.
Without a uC, it could be done but it will be very difficult and complicated.
That is why a uC is needed, to make the design simpler and effective.
But to do this you should know programing and also you should have a programmer to do this.

Further more you are asking for the entire ckt and a new one, which takes a long time to perfect.
We are not just here for that, we have our jobs and every one are really busy, we help in this forum in our free time, which varies a lot, sometimes we may be away for days depending on our workloads.
That is why we can't do such things.
U need to come up with a circuit and you need to start it and if a problem arises, we can rectify it for you.
We cannot spoon feed everyone. That is not the way to learn, Use ur imagination and the net, Google and you will find atleast one circuit that you can use and then try to improve it.
These things depend on what components you can get. And only you know what you have.
Why don't you try simpler things which is in range of your understanding.
 
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