alternation current circuit {= AC circuit}

earth circuit [= earth return circuit]

enlarged circuit and compensation circuit

single filip-flop circuit (sff circuit)

trip circuit and closing circuit

△-Σ circuit

1∶2 DEMUX circuit

1∶5 DEMUX circuit

10 kV circuit breaker

10 kV rural overhead line circuit

110 kV line control circuit

1100 kV SF6 circuit breaker

126 kV double-break vacuum circuit breaker

1DQJ circuit

1-tower 4-circuit

1-wire bus driving circuit

2 DEMUX circuit

2 M circuit

20 kV outdoor on-post vacuum circuit breaker