What is the current divider and where it is used

Often, the design of electrical circuits such situations arise when current flows in the circuit of the same denomination, and the load must be powered with a much lower consumption. Just for such cases and were invented current dividers, which are based on first Kirchhoff's law. In this article I will try to understand as much as possible and to explain how it all works. So, let's begin.

Table of contents

Definition and principle of operation

practical experiment

Examples of use in electronics current divider

Limitations in the use of current dividers

conclusion

Definition and principle of operation

So, first let's define the current divider. Divider current - it is a device by which to divide the current flowing in the circuit in two parts in order to use already divided current. Or, to put it another way, the current divider is required in the case where a large current flows in the circuit, and it is necessary to connect the load with a small consumption.

Current divider principle of operation is based on the Kirchhoff's first law, according to which the sum of all currents flowing into a node is the sum of all the currents flowing from the node.

For a better understanding, let's compare the divider with fast river, where rapid flow of water - is it is our current strength. And to reduce the force of raging water flow, you need only to divide it into two separate beds.

Exactly the same thing happens in electronics.

Therefore, in order to divide the strength of the current, we need to take a couple of resistors and connect them in a parallel manner.

Now examine just such a simple scheme:

The voltage at point "A" and "B" is the total for our two resistors. Each of the resistor has its resistance, but the total resistance will be calculated by this formula:

And according to the first law of Kirchhoff's total current is as follows:

And to find the currents I1 and I2 can be found by the formulas, using the following conversion:

Complex and unclear. Simply put, if instead of a resistor is connected, for example, a fan, then changing resistance of the second resistor, we will also change the current, and hence power, passing through the fan.

practical experiment

Let's take two resistances of different values.

Measurable pore resistance and the second resistors.

Now we expose the power supply voltage of 12 volts, and the two ends of the resistors are brazed together

Now measure the strength of the current flowing through the resistor with a smaller resistance, and then looking amperage second resistor:

Now solder the resistors in parallel and check what the current strength flowing through the parallel resistor:

Now we make a simple mathematical calculation and check the results:

0.094 + 0.134 = 0.228 A. And we got 0,223 A. The difference in the readings of 0.005 Ampere sleeping on the error of the instrument.

I hope to deal with practical work experience in a voltage divider became clear, and now let's see how the current dividers are used in electronics.

Examples of use in electronics current divider

In fact, current divider - is a very important element of all modern energy. For example, the most common ammeters are built on the principle of current dividers.

Ammeter located inside the shunt through which the majority of the current, and through a second resistor tested milliamps or microamps.

Limitations in the use of current dividers

As with any other device in the current dividers have restrictions on use. So an important condition for the correct operation of the device is the requirement that the load resistance was several orders of magnitude less than the resistivity of the current dividers.

Also active divider resistance inevitably reduce the efficiency of the whole circuit in general.

A resistor through which the majority of the current has to be powerful enough for successful heat dissipation.

conclusion

That's all I wanted to tell you about such an important element as a current divider. If the article was useful to you, or are interested in, be sure to vote Like it! And thank you for attention!