DIAGNOSTIC SYSTEM FOR ELECTROMAGNETIC VALVE DRIVE CIRCUIT OF ANTISKID DEVICE

摘要

PURPOSE:To detect the malfunction of a system before it is operated by providing a diagnostic circuit for checking the operating conditions of an electromagnetic valve drive circuit for electromagnetic valves. CONSTITUTION:A diagnostic circuit 20 generates a test signal to activate switching elements 16 and 17 by means of a control circuit 15. At the same time, the resulting condition of the switching elements is detected with the test signal to judge whether it is normal or abnormal. The pulse width of the test signal is made shorter than that of a normal drive signal, and the drive current flowing in solenoid coils 18 and 19 is adjusted so that it does not attain the operation level in terms of time.