| 摘要 |
<p>A switch having an indication lamp is provided to secure a stable operation of an indication lamp by supplying a fixed voltage regardless of a change of a load. When a switch(SW1) is turned on by an AC power source, a lamp is turned on. A down transformer(T1) is parallel connected to the lamp. A bridge rectifying diode(BR1) converts the AC power source into a pulsating current. A condenser(C1) removes a noise from the pulsating current. A smoothing condenser(C2) receives a noise-removed pulsating current. A zener diode(Z1) maintains a fixed voltage of 5V. An NE555 functions as a multi vibrator in order to control a LED. A high frequency bypass condenser(C4) removes a noise of the NE555. The LED is turned on in order to inform turning-on of the lamp.</p> |
