how to interface Relay to microcontroller

RRITESH KAKKAR

Joined Jun 29, 2010
2,829
Hello
abhimanyu143

I have fear in my mind, first time I am going to use relay in my project. I have done all work under 12 v dc. now I am trying to connect relay to mains power. that's why I need suggestion I don’t understand how to interface relay to 8051 and AC motor

relay has 5 pins
1. which Pins of relay connect to port of microcontroller (8051) ?
2. which Pins of relay connect to mains power ?
3. which pins of relay connect to AC motor ?
4. look at image. It is suitable for AC motor ?


abhimanyu143
it is very easy dear,
my suggestion is first learn relay it working then use/connect to supply.
if you see the part clearly after removing it blue cover then you can find the coil pins of electromagnet the real part of relay which contact the other pins.
called normal connect normal off
there are total 5 pins 2 of electromagnetic coil and 3rd is the pin which contact the n/off and n/on.
if the relay is off it contact pin in middle is upper side and when you will supply the 12V to it it will on automatically.
so, 12v is used to switch heavy load from its terminal in 220V.
If you are clear this line of information i will tell more further how to switch from 5V the 12V relay by BJT transistor or darling ton pair uln2008/uln2003
 
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