this invention is based on the contents of the u . s . pat . no . 5 , 831 , 349 and chinese invention patent zl94112284 . 0 , zl94114032 . 6 as their follow - up invention . the invention involves the technical schemes of several linkage apparatuses of ac two - wire solid - state switches . all of the ac two - wire solid - state switches of the linkage apparatuses must be the non - contact on - off in the main circuits of the ac two - wire solid - state switches of the said three patents . this invention is intended to combine several or multiple the ac two - wire solid - state switches into linkage apparatus so that all of the said switches have consistently - combined on - off actions , so that the application range of the ac two - wire solid - state switches is expanded from the single - phase circuit to three - phase circuit , from the low - voltage power grid to the high - voltage power grid .