| 摘要 |
PURPOSE:To enable a display lamp to be positively lit by connecting a diode in parallel to the charging resistance a time constant circuit with an anode being at the capacitor side in a lighting control for a brake display lamp used commonly for ordinary brake and parking brake. CONSTITUTION:When a brake switch 3 is closed in braking, a brake display lamp 1 is lit through a normally-closed contact 2a in a relay 2. On the other hand, when the switch 3 is closed continuously for a relatively long time such as parking time, a capacitor C10 is charged through resistors 12, 11 so that the output of a comparator 13 is changed over to low level after a predetermined time. Then a transistor Tr6 turned on to excite a coil 2b of the relay 2 for opening the contact 20 and turning off the display lamp 1. When the brake is thereafter released and the switch 3 is opened, the charge on C10 is discharged through a diode 16 and the comparator 13 produces the output of H level to turn off Tr6 and close the contact 2a. |
