The basis is an ordinary 100-watt incandescent light bulb.
First we need to dismantle the base. This is done as follows:
Use pliers to pry out the top contact of the lamp, then use a screwdriver and the resulting hole to get rid of the black dielectric. After this, we easily “tear off” the threads and the remains of the base. There may be glue left on the glass, that's okay. We will cover it with a new base.
Next comes working with glass! Therefore, we wear gloves and safety glasses.
At this stage we need to remove the inside of the lamp. To do this, use a straight screwdriver to gently press on the inner walls of the lamp. When the bulb with antennae and filament breaks, we take it out along with small fragments, wrap it in a napkin and throw it away.
We place the resulting vessel on the unnecessary lid with the hole facing up. To avoid getting your desktop dirty, place a napkin under the lid. After all, what follows is work with chemical reagents. I will say right away - they are safe and publicly available.
So-called chemical algae will grow in the lamp. To create them, we need liquid glass (sold in construction stores, hereinafter ZhS) and copper sulfate (can be found in garden stores, this is a fertilizer).
In a separate jar we make a solution: mix water and ZhS in a 2:1 ratio (two parts water, one part ZhS). By the way, liquid glass can be replaced with silicate glue, in which case the proportion will be as follows: 6 parts water, 1 part glue.
Instead of copper sulfate, you can use iron sulfate (also a fertilizer) or magnesium sulfate (sold in a pharmacy, this is a powder for algae to grow from it, you must first moisten it with a small amount of water and let it evaporate, thanks to this we will increase the size of the crystals, because what they the larger, the higher the algae will be). The color of chemical algae depends on the reagent: iron sulfate gives a black color, magnesium sulfate gives a white color, and copper sulfate gives a pleasant blue color.
So, let's take some vitriol.
And we put it at the bottom of the lamp.
And fill it with liquid glass solution. When pouring, drop a little solution onto the lid; it will dry and add stability to the entire structure. The chemical process has begun, and within a few minutes the first algae will begin to form.
They grow due to the fact that water from the solution gets inside the crystal, thereby changing its structure.
While the algae is growing, let's work on the electrical part.
Light-emitting diode I attached it to test tube caps (you can take a valerian cap).
We seal the lamp and contacts LED we place it as in the picture below, plus I soldered a short piece of wire so that it would fix the battery.
And don’t forget to glue the contacts with tape; the battery should not touch them.
Since in the future access to the battery will be difficult, it is necessary to optimize energy consumption. Yes, you can just install a switch, but it's too simple and uninteresting. Therefore, I created a simple adaptive brightness control scheme:
Parts List:
- VT1 - KT315 (or any other n-p-n transistor);
- VD1 - photodiode, anode (+)
- VD2 - Light-emitting diode;
- R1 - 100kOm;
- S1 - locking button (take the smallest one you find);
- BAT - coin cell battery (model CR2025).
The positive leg of the photodiode (to which the minus power is supplied) is marked with a white line on the part.
A voltage divider is assembled on resistor R1 and photodiode VD1, from the midpoint of which it is supplied to the base of transistor VT1. The load is our Light-emitting diode VD2. The more light falls on the photodiode, the less voltage is supplied to the base (inverse proportionality). I added the button for completeness of functionality.
This entire circuit must be placed at the bottom of the base. I took it from an unusable LED lamp
Its appearance is more beautiful than that of conventional lamp bases. You should first get rid of the plastic rim.
In the upper part of the base we drill two holes for the legs of the photodiode. They need to be lengthened by about a centimeter. Then we drip a little superglue and attach the photodiode.
Next, already inside the base, we solder the remaining components very compactly.
Three wires go to negative LED, to the plus and minus of the power supply from left to right, respectively. We fix the button with hot glue, the main thing is not to overdo it. Solder the battery quickly with a drop of soldering acid. Solder the wires into place.
We seal the lamp with a lid and cover it with a base. Due to the remnants of the old glue, the base fit tightly and securely.
That's it, the night light is ready! Thanks to adaptive brightness control, the LED does not light up during the day, and there is no point in turning it off unless necessary.
A few photos of the finished product:
