| 摘要 |
PURPOSE:To prevent an electronic circuit from being destroyed even if a power supply is interrupted by inputting the operating state of a single switching element ot the plural electronic circuits each driven with an independent power supply. CONSTITUTION:When a contact K1 is closed, transistors (Trs) Q1, Q5, Q1', Q5' are conducted, the 1st group terminal L1 is connected to a power supply voltage V, the 1st group terminal L1' is connected to a power supply V' and the 2nd group terminals H1, H1' are connected to ground potential respectively. Each electronic circuit detects respectively the closing of the contact K1 by detecting the potential change of the 1st and 2nd groups. If the power supply, for example, V is stopped, the 2nd groups terminals H1-H3 go to ground potential independently of the state of contacts K1-K12, no voltage is inputted to the electronic circuits driven by the power supply V from the 1st group terminals L1-L4 and the 2nd group terminals H1-H3 thereby the said electronic circuit is prevented from being destroyed. |
