2. VOLTAGE DIVISION RULE
In the field of electronics, a voltage divider is a
basic circuit, used to generate a part of its input
voltage like an output. This circuit can be designed
with two resistors otherwise any passive
components along with a voltage source. The
resistors in the circuit can be connected in series
whereas a voltage source is connected across these
resistors. This circuit is also called a potential
divider. The input voltage can be transmitted
between the two resistors in the circuit so that the
division of voltage takes place.
3. EXAMPLES AND APPLICATIONS OF VOLTAGE
DIVISION RULE
It is used to change a large voltage into a small
voltage. Generally, these dividers are used to reduce
the magnitude of the voltage or to create reference
voltage and also used at low frequencies as a signal
attenuator. For DC and relatively low frequencies, a
voltage divider may be appropriately perfect if made
only of resistors; where the frequency response is
required over a wide range.
4. 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.
5. 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. But 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.
8. Current Dividers
Current Divider circuits have two or more parallel
branches for currents to flow through but the voltage
is the same for all components in the parallel circuit
18. Four resistors of 2Ω, 3Ω, 4Ω and 5Ω respectively are connected
in parallel . What Voltage must be applied to the group in order
that the total power of 100Watts may be absorbed?
19.
20. Three resistors are connected together to form a current
divider circuit as shown below. If the circuit is fed from a 100
volts 1.5kW power supply, calculate the individual branch
currents using the current division rule and the equivalent
circuit resistance.
21.
22.
23. We can check our calculations as according to Kirchhoff’s
Current Rule, all the branch currents will be equal to the total
current, so: IT
= IR1
+ IR2
+ IR3
= 10 + 4 + 1 = 15 amperes, as
expected. Thus we can see that the total current, IT
is divided
according to a simple ratio determined by the branch resistances.
Also, as the number of resistors connected in parallel increases,
the supply ot total current, IT
will also increase for a given supply
voltage, VS
as there are more parallel branches taking current.
26. The equivalent resistance of four resistors joined in
parallel is 30ohms. The current flowing through them
are 0.5, 0.4, 0.6 and 0.1A. Find the value of
each resistor.
