| 摘要 |
PURPOSE:To improve reliability by employing a circuit for displaying a warning during the operation of a turn-off delay circuit and making it clear if the lighting of a lamp is due to the turn-off delay function by actuating the circuit. CONSTITUTION:A digital IC 4 is turned to high or low level by turns at every operation of an operation switch 3. A lighting device 2 is turned on during the high level, turned to the low level, and turned off after a certain time determined with a turn-off delay circuit 6. The digital IC is turned to the low level and a condenser C2 in a voltage retention circuit 7 is retained at the high level until the turn-off delay action stops. The output of the high level is inputted to an EXOR gate 8, Vc rises to the high level and actuates a warning display circuit 9 during the functioning of the turn-off delay. When the warning is not required, a changeover switch 20 is turned on and the output of the EXOR gate 8 is lowered to the low level to stop the warning display circuit 9. |
