INTRODUCTION
Voltage Divider Circuits are useful in providing different voltage levels from a common supply voltage. This common supply can be a single supply either positive or negative, for example, +5V, +12V, -5V or -12V, etc. with respect to a common point or ground, usually 0V, or it could be across a dual supply, for example, ±5V, or ±12V, etc.
Voltage dividers are also known as potential dividers, because the unit of voltage, the “Volt” represents the amount of potential difference between two points. A voltage or potential divider is a simple passive circuit that takes advantage of the effect of voltages being dropped across components which are connected in series.
The potentiometer, which is a variable resistor with a sliding contact, is the most basic example of a voltage divider as we can apply a voltage across its terminals and produce an output voltage in proportion to the mechanical position of its sliding contact. However, we can also make voltage dividers using individual resistors, capacitors and inductors as they are two-terminal components which can be connected together in series.
RESISTIVE VOLTAGE DIVIDER
Resistive Voltage Divider The simplest, easiest to understand, and most basic form of a passive voltage divider network is that of two resistors connected together in series. This basic combination allows us to use the Voltage Divider Rule to calculate the voltage drops across each series resistor.
RESISTIVE VOLTAGE DIVIDER CIRCUIT
Here the circuit consists of two resistors connected together in series: R1, and R2. Since the two resistors are connected in series, it must, therefore, follow that the same value of electric current must flow through each resistive element of the circuit as it has nowhere else to go. Thus providing an I*R voltage drop across each resistive element.
With a supply or source voltage, VS applied across this series combination, we can apply Kirchhoff’s Voltage Law, (KVL) and also using Ohm’s Law to find the voltage dropped across each resistor derived in terms of the common current, I flowing through them. So solving for the current (I) flowing through the series network gives us:
The current flowing through the series network is simply I = V/R following Ohm’s Law. Since the current is common to both resistors, (IR1 = IR2) we can calculate the voltage dropped across the resistor, R2 in the above series circuit as being:
Likewise for resistor R1 as being:
EXAMPLE
Let Vin=6Vv, R1=50kΩ , and R2=10kΩ Find V(out)?
V(out)=Vin(R2/R1+R2)
Vout=6V*(10kΩ/50kΩ+10kΩ)
Vout=6V*(60kΩ/10kΩ)=6V*(1/6)
Vvout=1V
Therefore V(out)=1V
Voltage Divider With 3 Resistor
is=Vs/Req
=Vs/(R1+R2+R3)
VR2=isR2=R2/(R1+R2+R3)*Vs
Similarly we can find VR1 and VR3
VR1=isR1=R1/(R1+R2+R3)*Vs
VR3=isR3=R3/(R1+R2+R3)*Vs
EXAMPLE:
Find the Voltage across R1,R2 and R3??
VR1=5kΩ/(5kΩ+15kΩ+10kΩ)*15V=2.5V
VR2=15kΩ/(5kΩ+15kΩ+10kΩ)*15VkΩ/(5kΩ+15kΩ+10kΩ)*15V=7.5V
VR3=10kΩ/(5kΩ+15kΩ+10kΩ)*15V=5V
Therefore the value of VR1=2.5V,VR2=7.5V and VR3=5V
After reading this tutorial on “Voltage Divider”. I hope you understood about voltage divider and I am pretty sure you want to know more about electronic circuits and IoT. To know more about IoT you can refer to the following blogs.
