One of the pillars on which many concepts in electronics are based is the concept of series and parallel connection of conductors. To know the main differences between these types of connections is simply necessary. Without this, it is impossible to understand and read a single diagram.
Basic principles
Electric current moves along the conductor from the source to the consumer (load). Most often, a copper cable is selected as a conductor. This is due to the requirement that is imposed on the conductor: it should easily release electrons.
Regardless of the connection method, the electric current moves from plus to minus. It is in this direction that potential decreases. At the same time, it is worth remembering that the wire along which current flows is also resistant. But its value is very small. That is why they are neglected. The resistance of the conductor is taken equal to zero. In the event that the conductor has a resistance, it is customary to call it a resistor.
Parallel connection
In this case, the elements included in the circuit are interconnected by two nodes. They have no connections with other nodes. Parts of a circuit with such a connection are usually called branches. The parallel connection diagram is shown in the figure below.
Speaking in a more understandable language, in this case all the conductors are connected at one end in one node, and the second in the second. This leads to the fact that the electric current is divided into all elements. This increases the conductivity of the entire circuit.
When connecting the conductors to the circuit in this way, the voltage of each of them will be the same. But the current strength of the entire circuit will be determined as the sum of the currents flowing through all the elements. Taking into account Ohm's law, through simple mathematical calculations, an interesting regularity is obtained: the quantity inverse to the total resistance of the entire circuit is determined as the sum of the quantities inverse to the resistances of each individual element. In this case, only elements connected in parallel are taken into account.
Serial connection
In this case, all the elements of the circuit are connected in such a way that they do not form a single node. With this connection method, there is one significant drawback. It lies in the fact that if one of the conductors fails, all subsequent elements will not be able to work. A striking example of such a situation is an ordinary garland. If one of the bulbs burns out in it, then the whole garland stops working.
The series connection of the elements is characterized in that the current strength in all conductors is equal. As for the voltage of the circuit, it is equal to the sum of the voltage of the individual elements.
In this scheme, the conductors are connected to the circuit alternately. And this means that the resistance of the entire circuit will consist of individual resistances characteristic of each element. That is, the total resistance of the circuit is equal to the sum of the resistances of all the conductors. The same dependence can also be derived mathematically using Ohm's law.
Mixed circuits
There are situations when in one circuit you can see simultaneously serial and parallel connection of elements. In this case, they speak of a mixed compound. The calculation of such schemes is carried out separately for each of the group of conductors.
So, in order to determine the total resistance, it is necessary to add the resistance of elements connected in parallel and the resistance of elements with series connection. In this case, a serial connection is dominant. That is, it is calculated in the first place. And only after that the resistance of elements with parallel connection is determined.
LED connection
Knowing the basics of the two types of connecting elements in a circuit, you can understand the principle of creating circuits of various electrical appliances. Consider an example. The wiring diagram of the LEDs largely depends on the voltage of the current source.
With a small network voltage (up to 5 V), the LEDs are connected in series. In this case, a through-type capacitor and linear resistors will help to reduce the level of electromagnetic interference. The conductivity of LEDs is increased through the use of system modulators.
With a 12 V network voltage, both serial and parallel network connections can be used. In case of serial connection, switching power supplies are used. If you are going to a circuit of three LEDs, then you can do without an amplifier. But if the circuit will include a larger number of elements, then an amplifier is needed.
In the second case, that is, with parallel connection, it is necessary to use two open resistors and an amplifier (with a bandwidth above 3 A). Moreover, the first resistor is installed in front of the amplifier, and the second after.
At a high voltage (220 V), they resort to serial connection. At the same time, operational amplifiers and step-down power supplies are additionally used.