the circuit on page 4 is shown in relay operated position. we know that there are two change over contacts termed as A and B
1st change over contact A Because the relay is shown in operated position, pin2 is shown towards pin3
1. normally closed pin.
2. common pin.
3. normally closed.
2nd Contact B
1. normally closed pin.
2. common pin.
3. normally closed.
this relay can be configured to work as
1. normal
2. slow to release,
3. slow to operate (which is also slow to release)
4,. polarized to operate ( or release ) depending direction of current in the main winding.
brief description:
coil main +X and -X here +X is where the positive voltage is applied as input and it comes out at -X.
the Y coil helps to make relay slow to operate -- example if Y-coil is short circuited, the relay exhibits a style where the relay is slow to operate and also slow to release.
like wise keeping Y coil open and connecting a diode across (in parallel) X coil makes the relay operate normally but release slowly after removal of drive voltage , as the back emf in the x-coil sustains current in the x-coil for little more time. (virtually the back emf wont allow the current do decay that fast when the diode is not there across it.)
now we can make the relay polarized also, by pre driving current in Y coil
if x-coil has a voltage to add magnetic field, nothing happens and the relay keeps operated.
On the other hand if a reverse connection is given for x-coil to drive current opposing the magnetic field produced due to Y coil, the relay changes over to release position, depending on resultant current strength
hope i am able to express.