A voltage divider, what it is and how it works in practice, we assort

So; t is a voltage divider? Referring to Wikipedia, there is recorded the following definition: a product in which the input and output voltages interconnected certain transmission ratio. It does not sound very clear. In this article I will try to tell about the voltage divider in simple language.

Content

Existing types of voltage dividers

A bit of theory and boring formulas

Anchoring in practice

Variable resistor

conclusion

Existing types of voltage dividers

voltage dividers are linear and non-linear. divided into linear, in turn:

1. resistive;

2. capacitive;

3. Inductive.

A nonlinear include, for example, parametric voltage regulators.

It would be desirable to observe that the principle of operation of any divisor is identical and only the differences are caused by a set of components of which it is assembled. Therefore, the resistive voltage divider will be considered as an example of how the simplest of all.

A bit of theory and boring formulas

Let's look at the following picture:

Scheme presented above is formed of a pair of resistors connected in series. By this scheme we can easily make both permanent and alternating voltage. And as soon as we connect such a scheme, it will come into force Ohm's law, which will allow us to count a lot.

Thus, a series connection of resistors of resistance will be equal to the sum, namely: R1 + R2. And it turns out that the current strength, will be as follows:

Also note that with this compound resistors amperage will be the same at any point along the chain.

So, since we resistors have different resistance, according to Ohm's Law, the voltage on these elements will also be different, that is, the resistor R1 is U1, and on R2 will be U2.

Knowing this, we can calculate the strength of the current is already so:

Performing simple transformations final formulas for calculating the output voltage will have the following form:

It turns out that these formulas, we can calculate a voltage drop will be at each of the resistors.

Simply put, a series connection of resistors on each of them will have their own power and the sum of these voltages will be equal to the supply voltageThat is, will we have the following expression:

That is, with the help of resistors was simply a division of voltage coming from the power supply.

Anchoring in practice

So, with boring theory finished, let's make a practical experiment. To do this, take a couple of resistors (with different capacities), power supply and multimeter.

We produce our measurement of resistance of resistors:

Expose the power supply, for example 10 V, and resistors are interconnected in a sequential manner:

Now we make the measurement of the voltage across the first resistor, and then on the second:

Now we add our obtained voltage:

3.307 6.76 B + B = 10.067 volts. The difference of 0.067 Volt sleeping on the accuracy of the multimeter and power supply.

Here we examined the simplest example of a voltage division.

Now, for the entirety of the experiment we shall see in practice that the current strength remains unchanged throughout our network in series connection.

As seen from the above presented photos, the current is the same everywhere.

Variable resistor

For smooth use adjustable voltage dividing resistors.

The principle of this resistor is that between the two extremes 1 and 3 constant resistance is present. A secondary output resistance with respect to the extreme changes if postroechnyh twist handle.

We expose in our power supply 10 Volt and produce a voltage measurement between the outermost tracks:

Now by the controller expose any position and measure the voltage across the terminals 1-2 and 2-3

Still we summarize the resulting value of 6.87 + 3.199 = 10.069 volts. Extra 0.069 volts still blamed on the error.

conclusion

Of course, in modern electronics such dividers are no longer used. But if you collect any home-made and it is necessary to perform voltage division, the resistor voltage divider fits perfectly. If the article was useful to you, you will appreciate it Like. Thank you for your valuable attention!