| 摘要 |
PURPOSE:To save the labor of wiring, and to prevent false connection, by eliminating the need for multiple-wire wiring by controlling a lamp in a three mode by using a signal transducer that operates by detecting the OFF time of a switch. CONSTITUTION:When a power switch 1 is in ON after it is in OFF for a sufficient long time, the voltage drop of a resistance R2 is large because charge is not accumulated to a condenser C2 of a circuit 5 of detecting OFF time, a Zener diode D2 is conducted to result in the ON of SCR, a relay Ry is excited, and a contact Ry' is changed over to NO, thus lighting a 1st lamp 7. When the power switch is in OFF and the power switch 1 is in ON just after the 1st lamp 7 puts out, both end voltage of the resistance R2 is not more than Zener voltage because the charge of the condenser C2 remains, SCR cannot be triggered, and the contact Ry' is changed over to the NC side, thus lighting a 2nd lamp 8. Consequently, the lamps can be controlled in a three mode by two-wire wiring. |
