Fill This Form To Receive Instant Help
Fill This Form To Receive Instant Help
Homework answers / question archive / It is desired to control the coil of a relay CR4 using relay contacts CR1, CR2, and CR3
It is desired to control the coil of a relay CR4 using relay contacts CR1, CR2, and CR3. CR4 is to be ON whenever a majority of CR1, CR2, and CR3 are ON (i.e. any two or all three). Draw a one-rung relay ladder diagram that will produce the logical operation.
Please see the attached file.
Since there are three possibilities to turn on the majority of the three relays CR1, CR2, CR3, therefore we need three paths. CR1 and CR2 on, CR3 irrelevant is the top path. CR1 and CR3 on, CR2 irrelevant is the middle path. CR2 and CR3 on, CR1 irrelevant is the bottom path. I say irrelevant because if all three relays are on then all three paths will be turning CR4 on.
