Serial and Parallel Connection

One of the whales on which many concepts in electronics are held is the concept of sequential and parallel connection of conductors. Know the main differences of these types of connection is simply necessary. Without this, one can not understand and read a single scheme.

Basic principles

Electric current moves along the conductor from the source to the consumer (load). Most often, a copper cable is used as a conductor. This is due to the requirement that is imposed on the conductor: it must easily release electrons.

Regardless of the method of connection, the electric current moves from positive to negative. It is in this direction that the potential decreases. At the same time, it is worth remembering that the wire that the current flows along also has resistance. But its meaning is very small. That's why they are neglected. The conductor resistance is assumed to be zero. In the event that the conductor has resistance, it is customary to call it a resistor.

Parallel connection

In this case, the elements in the chain are joined together by two nodes. With other nodes they have no connections. The parts of the chain with this connection are usually called branches. A diagram of the parallel connection is shown in the figure below.

In a more understandable language, in this case all the conductors are connected at one end with one end, and the second one in the second. This leads to the fact that the electric current is divided into all the 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 by simple mathematical calculations, an interesting regularity is obtained: the reciprocal of the total resistance of the whole chain is defined as the sum of the reciprocals of the resistances of each individual element. Only elements connected in parallel are considered.

Serial connection

In this case, all the elements of the chain are connected in such a way that they do not form a single node. With this method of connection, there is one significant drawback. It consists in the fact that if one of the conductors fails, all subsequent elements will not be able to work. A striking example of this situation is the usual garland. If one of the light bulbs burns out, the whole garland stops working.

Sequential connection of the elements is different in that the current in all conductors is equal to. 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 in a chain in turn. And this means that the resistance of the whole chain will be composed of individual resistances, characteristic for each element. That is, the total resistance of the circuit is equal to the sum of the resistances of all conductors. The same dependence can be derived in a mathematical way, using Ohm's law.

Mixed circuits

There are situations when one can see simultaneous and parallel connection of elements on the same scheme. In this case, they speak of a mixed compound. Calculation of such schemes is carried out separately for each of the group of conductors.

So, to determine the total resistance, it is necessary to combine the resistance of the elements connected in parallel and the resistance of the elements with a series connection. In this case, the serial connection is dominant. That is, it is calculated first. And only after that determine the resistance of elements with parallel connection.

Connecting LEDs

Knowing the basics of the two types of connection of elements in the circuit, one can understand the principle of creating circuits of various electrical appliances. Let's consider an example. The connection scheme for the LEDs depends largely on the voltage of the current source.

With a small mains voltage (up to 5 V), the LEDs are connected in series. Reduce the level of electromagnetic interference in this case will help the capacitor type and linear resistors. Conductivity of LEDs is increased due to the use of system modulators.

With a voltage of 12 V, both serial and parallel network connection can be used. In the case of serial connection, use pulse power supplies. If a chain of three LEDs is assembled, then you can do without an amplifier. But if the circuit will include more elements, 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 exceeding 3 A). And the first resistor is installed in front of the amplifier, and the second - after.

At a high voltage of the network (220 V), a serial connection is used. At the same time, operational amplifiers and lowering power supplies are additionally used.