March 9, 2012 at 1:24 pm #4763bobbyParticipant
i am doing a project on room light controller using 8051..
i am using a pcb relay for controlling the light..
i have a doubt regarding the relay pins….i have a doubt regarding which are the coil terminals and which terminals are nc ,no and common!!i am posting a picture of it! pls help!!March 31, 2012 at 10:15 am #7367Mehtab AliParticipant
see the post given in the forum of paul ” identifying the primary and secondary of transformerApril 12, 2012 at 10:06 am #7420AJISH ALFREDParticipant
You can follow the procedure to find out pins of any relay.
Apply voltage less than the rated voltage to each possible pair of pins. Whenever you get a clicking sound, those are terminals of the relay coil. Now take multimeter and put it in the continuity mode. Take a pair from the remaining three pins. When you get the beep sound from multimeter, those two pins are normally closed (NC). The last remaining pin forms a normally open (NO) with any one of the pins in NC pair. To find out this common pin, once again apply voltage to the terminals of the coil and find out, with which pin our last pin shows continuity, using a multimeter.
Now you know the coil terminals, common pin, NC pair and NO pair.July 7, 2012 at 8:07 pm #8217sathyamoorthyParticipant
why this kolaveri.I know all the termninals.
in the picture
1.one line which has a three pins
the centre one is common
and the two terminals for applyring the voltage.
2.in the second which has a two pins
keep the multimeter in the continuity mode.keep one terminal of the mulimeter into the common.and check the othere side terminals /if multinmeter beeps that is NC.and another one is NO.July 27, 2018 at 10:48 am #14877AmanParticipant
At which side of Relay you see the 3 pins or 3 terminal– This side the middle pin of both side pin is the Common (COM) for the Load input (AC or DC). And both side pins are the DC Input supply pin for the coil of relay.
So the which you see the 3 terminal – here you both side (Except middle) pins are connect with DC supply for relay input.
And which side you see the only 2 terminals – These 2 terminals are for Load Output . In which one is NC (normarrly Connected) and one is NO (Normally opened) . For finding which pin is NO and Which Is NC use the multimeter or ant continuty tester.
Generally On PCB Relays -there are pin connection name is denoted on relay body near the all pins.
For more go to http://www.circuitspedia.com/
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