Question

2
develop the schematic of a relay circuit
that
logic gate function.
emulates
OR​

Answer 1

This is basic example of relay logic, first we create  step for this circuit

Step 1:- When we press push button, relay should be on, It means we use NO push button because when we press this switch supply goes forward.

Step 2:- When supply comes to relay coil, relay should be ON. Here relay is 24 V DC operated. 

We connect relay and push button as per figure. When we press push button, supply goes to relay A1 point and relay gets ON and its contact changes, but when we release push button supply cutoffs and relay gets off. But relay not do not fall in hold. So here we think what we shall do for relay to hold. Now we use NO contact of relay for hold.

We connect +24VDC to COM point of relay and NO point to A1 Point of relay. When we press Push button supply goes to relay, Relay turned ON and contact changes NO point became NC point. Now +24VDC supply direct connect to A1 and relay turned ON. If we release Push button supply cuts from the push button but the supply is permanently coming from NO point and relay permanently ON or on hold.

Now we want to OFF this relay, how we OFF this relay? Listen! On above example supply permanent coming from NO point that supply do continue ON   Relay. If we disconnect this supply using any element or device relay will be OFF. 

Hello This might help you.. and also don't forget to refer those attachments to understand clearly..