Homemade bulb current limiter

This is one of the most essential safety devices you must have if you work with electronics. Not only for the safety of the device you are making/troubleshooting but also for you and your electric installation. It is a famous device - the light bulb current limiter also know as dim bulb.

The construction is very simple, that's only a high wattage bulb connected in series between your device and the wall.

Here is the schematic:

I recommend to use a high wattage filament bulb, like a 150w or 200w, usually the rule is to use a bulb with a higher power than the device do be tested. Please not that the wattage must be the real and not the "equivalent" as we find in modern fluorescent lamps.

It is mainly used as a "detector" for short circuits: if your device has a short it will draw a lot of current from the mains and the bulb will be as bright as it can, limiting the current because itself will convert the energy into light and hot. If the device has no shorts, the bulb will remain off or will dim slightly (this will depend on the difference of power consumption from your device and the power of the bulb, the bigger the difference, the less it will dim).

The draw above is self explanatory, but take also a look at the one I built:

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DIY mineral specimen storage box

There are several ways of storing rocks and minerals specimens. Some prefer to have them visible, other prefer to have them secured in boxes. Personally, I prefer to have them stored in a box, so they don't get dirty with dust, so I decided to build a simple wooden box. It is a simple rectangular box with small boxes inside like drawers that are pulled from top. Dimensions of the main box are 40cm length x 20cm wide x 25cm height. There is space for about 4 drawers inside. I have organized the smaller specimens into paper boxes, although the larger specimens are loose. You can see a small video of how it works to open and pull the inner drawers: https://www.youtube.com/shorts/LhDBVJ7s5Vk I have used this style of box to store minerals but I can be used for any other kind of collectible.

Pressure lamp tank crack repair

I have an old kerosene pressure lamp, a Ditmar Maxim 520, but when I bought it, it come with some little cracks in the tank, so the first time I tried to turn it on, I noticed the kesorene leaking at the bottom. Searching in some forums for a possible solution, I have found a simple one: filling the cracks with tin solder. Here is a step by step if you also need to repair your pressure lamps: 1 - Identify all the cracks. 2 - With a dremel, open the cracks exposing the internal metal (make sure your tank is empty and dry of kerosene). 3 - With a torch and tin solder (the one used in electronics), fill the exposed metal crack with it. 4 - Test the pressure before adding kerosene. 5 - If the pressure keeps ok, you are ready to use your lamp again! Here is a small Youtube short video of the process: https://www.youtube.com/shorts/0442OXCgXjc This is the final repaired tank:

DIY sheet metal brake

One of my hobbies is to build electronics projects, like metal detectors for treasure hunting. Usually electronics boards are hold inside a plastic or metal box. There both in the market, but usually they are not so cheap. One solution I thought about, was to build my own boxes using aluminum sheet as it is a soft metal. Although aluminum is soft, for the thickness I want to use (2mm) it is not so easy to bend it by hand, so I searched a bit how to make a tool to bend the metal with the less effort possible and with good results at the end, I came up with this, using only 3 pieces of wood, 2 screws with bolts and 2 hinges: This is known as a sheet metal brake, mine is simple, made of pine wood but I recommend you to use harder woods, specially if you need to bend metals harder tha aluminum. I think you can replicate one easily just by looking at the pictures above, so I'm not provinding any measurements but if you need, please write a comment below. For different sizes or formats ...

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