what is voltage devider?

Answer 1

In electronics, a voltage divider is a simple device designed to create a voltage (Vout) which is proportional to another voltage (Vin). It is commonly used to create a reference voltage, and may also used as a signal attenuator at low frequencies. Voltage dividers are also known by the terms resistor divider and potential divider.

Answer 2

A voltage divider is typically two resistors connected in series. One side of the two resistors is connected to an input voltage. The other side is connected to ground. You "tap" the output from the connection between the two resistors.

So like this:

VIn --[R1]---- output ---- [R2] ----- GND

Now suppose Vin is 20V and R1=R2=100 ohms. The total resistance seen by Vin is 100+100=200 ohms. Ohm's law tells us that the current drawn is 20/200 = .1 A = 100mA.

So if you took a good voltmeter and measured the voltage across R2 it would be .1 * 100 = 10V. This is exactly half because R1=R2. The general formula we just used is:

Vout = R1* Vin /(R1+R2)

Which is usually written:

Vout = Vin *R1/(R1+R2)

In practice, these dividers aren't usually very practical because anything you use to draw current from Vout is effectively a resistor in parallel with R2 and that changes the formula. So if you connected a load to Vout that is expected to draw 1mA (.001A) you can assume it is RL = 10V/.001A = 10K. But putting a 10K resistor across R2 (100 ohms) makes it really 99 ohms. That's not too bad (use the formula to see how bad) but usually the load is smaller and the error is worse. In addition, consider that for 1mA of current supplied you are "burning" 100mA of current in the divider. So in practice you probably use a different circuit to convert one voltage to another (like a voltage regulator, for example).

The practical importance of a voltage divider is that many real circuits LOOK like voltage dividers -- particularly if you use Thevinin's thereom in analysis. So a Wheatstone bridge, for instance, is just 2 voltage dividers. The bias network for an amplifier or an opamp feedback loop can look like a voltage divider. Even a car stereo. The output looks like a voltage source and a resistor (usually 8 ohms). The speakers are also 8 ohms. So if the voltage at the speaker is, say, 5V then the output from the car stereo must be 10V. Now 5V through 8 ohms gives you the power (E*E/R). What happens if the speaker was 4 ohms? What happens if the speaker were 100 ohms? Where is the maximum power through the speaker obtained? An interesting question to answer with only two formulas involved: the voltage divider relationship and ohm's law for power (that is, power = E*(E/R) which is just really E*I in disguise.

Answer 3

A voltage divider circuit is (in it's simplest form) a circuit that contains two resistors wired in series between a Voltage source and return, commonly ground.

A measurement between the resistors will differ from the source voltage by an amount determined by the rating (ohms) of the resistors. By varying the number, rating, and placement of the resistors, you can generate whatever voltage is required.

Answer 4

In electronics, a voltage divider is a simple device designed to create a voltage (Vout) which is proportional to another voltage (Vin). It is commonly used to create a reference voltage, and may also used as a signal attenuator at low frequencies. Voltage dividers are also known by the terms resistor divider and potential divider.

Answer 5

a magnetic Field