Automatic transfer switch-Electrical control β control circuit- DOL starter- Direct on line starter- Electrical wiring- Electrical technology- Direct one line starter- Star delta starter- Electrical switches-Timer- One way switch- Electrical sockets- Electrical transformer- synchronous machine- D.C machine- A.C machine- two-way switch- Intermediate switch - Star connection -Delta connection β MCB-MCCB-ELCB-RCBO- Three phase system- single phase β Electrical Engineering basics β Electrical tools -Electrical technician.-Circuit breaker- induction motor- D C motor