| 摘要 |
PURPOSE:To reliably detect a disconnection of power output elements with a simple circuit, by connecting a resistor to each of power output parts in parallel to provide a detecting circuit to detect the change in resistance resulting from the disconnection of power output elements. CONSTITUTION:When one of drivers DR0-DR3 is on (off), and the one of relays RY0-RY3 which corresponds thereto has been disconnected, the potential at one of points P0-P3 is extremely lower than before the disconnection of the relay, and the output of one of inverters INV0-INV3 becomes H. Consequently, an AND circuit is opened to report abnormality. In this case, because the potentials at the points P0- P3 are independent of the on and off of the drivers DR0-DR3, the disconnection accident of the relays can be detected independently of the on and off of the drives. By such a constitution, the disconnection of power output elements can be reliably detected with a simple circuit by using inexpensive parts or elements. |
