What is a relay and which one should i use ??

[harshi414]

https://www.edaboard.com/threads/53996/ thsi thread doesnt serves my purpose.

i need to make a motor rotate with an external battery of 9 v caonnected in series with the motor and the realay !~.. and also want the other circuit to be connected to the serial post of the computer.

the pc supplies 5v and the externmal battry that i have attached is of 9v(to drive the motor.)_

what actually i want to do. ???
i have a programe in C language which allows me to send dc 5v signal to data pins of the serial port ! so i want that when i send the 5v signal then the relay completes the external circuit and the mortor starts running !

so which relay will solve my purpose.?? really confused being a computer science enginnering student.
seeking help !!

and moreover i need not convert 5v to 9v ! so dun get confused by that . 9v is in the extetrnal circuit and has no connection with the serial post !

 

[Genovator]

Relay is nothing but a switch in simple sence. You can know about relay from wikipedia... https://en.wikipedia.org/wiki/Relay

Since its a low voltage operation and the driving of motor is done by a logic 5v source, I say you can use both MOSFET and electromechanical devices as a relay.

 

[xbased]

If i got your point you have to use this:



You have to connect the battery ground to the serial port ground in order to work.

 

[asad parvez]

In ur case, there is no use of relay....u can use ic inrtead of relay....

Using Ic L293D u cam control 2 dc motors....u can download data sheet and easily can operate this ic....

I also had xperience with this ic in 2nd year of engineering when i made remote controled car....

Remember ic L293D

refer datasheet n go through it....best of luck