If you have a common door separating a private corridor for several apartments, you probably have been in a situation when a bulb went off in the said corridor.
And while there is plenty of alpha males among your closest neighbours, no one gives a fuck to change the bulb. Except you. It looks like if this happens while you are away for a month, they all will die in twilight. You are also often too lazy to bother, since it’s not exactly clear is this a dead bulb or no power, and you don’t really feel like exercising fsor nothing. I’ll show how to make very basic indicator, so that you will always know at first glance if it’s power or bulb. You will need a piece of electric wire and a neon bulb – you may take out one from a lights switch or power extender. Note that the bulb comes bundled with a resistor. Solder the neon bulb parallel – note, parallel. If you plan to connect a lamp, attach a screw terminal. Now connect this assembly parallel – once again, parallel to the light source you wish to supervise. If its a daylight tube, they usually have a terminal inside which you can screw additional wires to. Put everything back together. If you did everything correct, the neon bulb will light up. Now you can easily tell if the bulb is dead or there is simply no power. If the bulb is off and the neon light is on, that means that the bulb should be replaced. If the neon bulb is also dark, the power is down.