| 摘要 |
PURPOSE:To assure the failsafe function of light control by providing a backup circuit in parallel with main circuit of light control while integrally assembling a monitor circuit for continuously monitoring the operating condition of both systems. CONSTITUTION:When the ignition switch SW1 is turned on while the light switch SW2 is turned off, current flows through a circuit of check relay 121, transistor Q1, relay RY1 and a circuit of check relay 122, transistor Q2, relay RY2 to close (a)-contact of each relay. If any one of main circuit 71, backup circuit 72, Q1, Q2 or relays 121, 122 is in fault, the check current doesn't flow and it is indicated by the photo-diode 11 in the monitoring circuit 8. Furthermore the monitoring circuit 8 has a coincide circuit 9 for monitoring the outputs from both circuits 71, 72 when both of SW1, SW2 are turned on. |
