Resistors are important elements in electrical circuits. They are generally used to obtain heat from an electrical current. This is because these materials oppose the passage of current, so the material heats up but does not melt and converts electrical energy into heat energy, a phenomenon known as the Joule effect.
Today, we will see how to make simple electrical resistors with homemade materials that can generate enough resistance to the passage of current, without the need to use nichrome wires.
- A graphite pencil.
- Enamelled copper wire.
- A pen or spool of thread.
- Power supply.
- A multimeter.
Creating our first simple resistor
The first resistor we are going to create is made with graphite from a pencil, as graphite itself is a pretty good resistor, what we need to do is to make a small circuit and measure the resistance generated.
To make the circuit, we must place the electrical source and use wire to connect the poles of the source to each end of the graphite rod that we have taken out of the pencil. The longer the graphite rod, the more electrical resistance we will generate with the rod. To measure the number of ohms, we must connect a multimeter between the connections of the rod and check the measurement.
Creating a second resistance
Another resistor that can be made at home is one based on coils of copper wire around a cylindrical element, which can be a spool of thread or a biro.
The more loops we make around the cylindrical object, the higher the resistance and the smaller the wire gauge, the higher the resistance.
To test our resistor, we connect it to the power source and with the help of a voltmeter we measure the number of ohms registered. Also, we can notice how the wire heats up and can become incandescent depending on the wire size and the power of the power source.