Electronics

Since we’ll be using electronic components for our project, we need to familiarize ourselves with circuits and electronics. But don’t worry! You don’t have to memorize everything! 😮‍💨 You can always come back to this page later to refresh your memory.

Here are some terms you’ll come across more often when working with electronics:

Voltage (V)

Voltage is a fundamental quantity in electrical engineering. It can exist without any current flowing and simply indicates the “strength” of a voltage source. You can think of it like a compressed spring waiting to let the current flow when you flip a switch or connect a device.

Current (A/mA)

Current, also known as electric current, indicates the amount of electrical energy flowing through a conductor per unit time. It’s similar to the amount of water flowing through a hose when you turn the faucet slightly or fully open it.

Power (W/mW)

Electrical power refers to the product of voltage and current and can, for example, describe how much heat an electronic component generates. Power can also be expressed as the amount of energy converted or transferred per second by a device.

Conductor

To allow current to flow, we need a conductor. This is typically a material made of metal (such as copper, aluminum, silver, or steel), often in the form of a cable or printed traces on a circuit board. In general, any material that allows current to flow relatively unimpeded without significant power consumption can be considered a conductor.

To prevent current flow at specific points, insulating materials are used, such as the insulation around a cable. An uninsulated cable could redirect current flow uncontrollably when in contact with skin or other metals. Non-conductive or insulating materials are substances that do not allow current to flow significantly, such as many plastics, ceramics, glass, or porcelain.

It’s important to ensure that non-insulated parts of a cable or component do not come into contact with other objects, as unintended current flow can occur.

Voltage Source

Although the terms “current source” and “voltage source” have different meanings in electrical engineering, for simplicity, we will use the term “current source” as a source that provides electrical current at a specific voltage. This can be a generator, a solar cell, a battery, an accumulator, or even the power grid. Usually, the applied voltage is indicated for any power source, for example, 1.5V for an AA battery. Energy storage devices like batteries or accumulators are often named together with their capacity, which actually refers to the amount of charge and is often given in ampere-hours (Ah) or milliampere-hours (mAh).

In our project, we’ll use the USB port of a computer as the voltage source. The USB port has a voltage of 5V.

Circuit

Current can only flow in a closed circuit, meaning a path that leads from the positive terminal to the negative terminal of a power source in the case of direct current. Within this circuit, one or more electrical components (e.g., a light bulb, motor) that serve a specific function are located. If a circuit is interrupted at any point, no current will flow.

Circuit Assembly

Normally, the components of electronic circuits are robustly connected to prevent unintended short circuits. This is usually achieved by soldering the connection points using soft metals (silver or lead alloys), resulting in a conductive and stable connection.

However, if you experiment a lot or need to modify a circuit frequently, soldering can be inconvenient and time-consuming. In such cases, you can use a solderless technique: the breadboard. Here, the components are inserted into a grid of partially connected wires.

Important: Always connect the power source after the rest of the circuit has been assembled and checked!

Short Circuit

A short circuit refers to a condition in which current flows where it shouldn’t. This can be especially dangerous with high voltages and currents, leading to electric shocks in humans or explosions and fires in systems or devices.

Water in combination with dissolved salts (tap water and especially seawater) can also become a fairly good conductor. Therefore, any exposed electrical and electronic components should be kept away from moisture and water.

However, it’s important to note that we’ll be working with a maximum of 5 volts, so there’s no danger to humans. Nevertheless, caution should be exercised when working with electricity. For example, if components are connected incorrectly, it can lead to a short circuit, causing components to start burning and potentially causing significant damage.

Important: Never directly connect both terminals of a power source, as this will cause a short circuit!

Electronic Components

Electronic components (also called devices) are a central part of an electrical circuit and possess various characteristics and functions. Each component typically serves a specific function but may be composed of different subcomponents. Each component is usually labeled, but the labels are often too small to include all the information. Therefore, the manufacturer often provides a datasheet, which provides extensive information about the purpose, usage, performance potential, and characteristics of the component. Datasheets can be challenging for beginners to read but provide essential data that is crucial for the success of an electronic circuit.

The components we’ll be using usually have multiple terminals, which we’ll briefly explain here. These terminals can be in the form of connection pins (metal pins) or connectors:

• the positive terminal is marked with plus sign
• the negative terminal (ground) is marked with G or minus sign
• the terminals for analog and/or digital signals (explained in the next section)

Multimeter

Multimeters are versatile measuring instruments used for a wide range of electrical measurements. They can be used for measuring voltage, resistance, and current, among other things.

A multimeter consists of:

• A display for reading the measured value
• A rotary switch for selecting the measurement range
• Two or more jacks for connecting the test leads
• Two test leads with probe tips (red and black), which are inserted into the jacks to establish the conductive connection between the device and the test object

For more information on using the multimeter, refer to the Debugging mit dem Multimeter section.

Analog and Digital Signals

An analog signal can take on continuously variable values, while a digital signal can only take a limited number of discrete values, typically 0 and 1.

An important difference between analog and digital signals is the method of transmission. Analog signals are transmitted through a continuous, continuous electrical wave, while digital signals use discrete electrical impulses.

We’ll be working with both types of signals in our project.

The explanations were partly taken from elektro.turanis.de.