A serial connection is a connection in which the elements are connected at only one end. The sequence is characterized by the fact that it excludes any branches.
A serial connection differs from a parallel connection in that a connection is made in parallel, which must have at least two nodes.
Resistors are elements of artificial resistance. They are used in electronics as an additional load to reduce the current or voltage of the circuit. How is it done?
If it is necessary to reduce the current, resistors are connected in series. In this case, the current of each resistance is the same, but the potential difference is different. It should be noted that the potential difference is the magnitude of the voltage drop, it directly depends on the resistance of the resistor.
For example, in a circuit with a voltage of 220 V there is a coil with a resistance of 1 ohm. If a phase is applied to one of its ends, and zero to the second, then in fact a short circuit will occur, since 1 ohm is too small. There will be a huge current, the coil will burn out, andthe network will fail. If you put two 500 kOhm resistors in series with the coil, then there will be no short circuit, and the coil will work as it should.
When connected in parallel, the currents of each branch will be different, but the voltages will be the same. Thus, the magnitude of the current of each section depends on the resistance of this section. This circuit is used to increase the voltage drop. For example, the coil resistance is designed for 50 V. To connect it to a 220 V network, you must put the appropriate resistance in parallel with it. A voltage drop will be created on it, and the coil will not burn out.
Thus, parallel and series connections are used in special cases and work according to Ohm's law.
If LEDs are connected in series, then we must remember that if at least one of them fails, the entire chain will go out. As already mentioned, the current is one, at the place of the break, the charges stop flowing, and the circuit breaks. When connected in parallel, it doesn't matter which LED is faulty, the others will stay lit.
If series resistance is carried out using the same values of resistors, then its total value will be equal to the product of one of the resistances by the total number of elements.
If the resistor values are different, then their total resistance will be equal to the sum of the resistances of each element.
In a parallel connection, the calculation is carried out a little differently. ToFor example, there is a circuit of three resistances with denominations R1, R2, R3. To find out the total resistance of the circuit when connected in parallel, it is necessary to calculate the sum of the reciprocal values of these values, that is, add three fractions 1/R1 + 1/R2 + 1/R3. Fractions are reduced to a common denominator - and the result is calculated. The resulting fraction is reversed and the final value is calculated.
In order to select resistances for any circuits, it is necessary to make calculations correctly. Some experts try to select resistors by experimentation. However, even in this case, it is necessary to at least approximately know which resistor values can be optimal.
