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# What is a voltage divider biasing?

###### Wiki User

###### 2009-04-10 06:31:57

Biasing-Application of suitable DC voltages to operate our

amplifiers in desired region of operation(say active or saturation

or cut-off region) complying our needs.However in order to maintain

a constant Q point irrespective of various external factors,hence

it again comes to the need for biasing that compensates the change

in external factors suitably thereby maintaining a constant

Q-point. Voltage divider bias or self bias is a process of suitably

biasing amplifier by connecting two resistors in series in the

answer. By proper selection of resistors R1 and R2, the operating

point of the transistor can be made independent of β.

## Related Questions

###### Asked in Electronics Engineering

### Why voltage divider biasing are used mostly?

Voltage Divider biasing is widely used in amplifier because of
its stability factor .it has a good stability then other three type
of biasing .
stability factor in VDB (Voltage divider biasing) is
(β+1)(1+RB/RE)
S=------------------------
(β+1)+RB/RE
if RB/RE <<1 then the equation indicates that S=1
it means VDB has a good stability .

###### Asked in Electronics Engineering

### Why voltage divider biasing circuit is the widely used biasing?

In a voltage -divider circuit method for biasing a transistor ,
we have two resistors R1 and R2 a DC supply voltage VCC and other
components like collector resistor , emitter resistor are also
present.
here biasing is done by the help of voltage drop across the
resistors
to understand the reason behind the extensive usage of voltage -
divider method we need to know about the term stability.
Stability factor of a transistor is defined as the ratio
of amount of change in collector current to the amount of change in
the same collector current with the base open(leakage current due
to minority charge carriers)
lesser the stability factor ------ that type of biasing is
more desired
the stability factor for voltage divider method is nearly
equal to one.

###### Asked in Electronics Engineering

### How does the voltage divider biasing network got its name?

Because that's what it is. It is a voltage divider.
Two resistors in series will have the same current through them.
This is Kirchoff's current law. By Ohm's law, then, the voltage
across each resistor is current times resistance, and this is a
linear function. By Kirchoff's voltage law, then, the total voltage
drop across both resistors is equal to the input voltage.
Two resistors of the same value will divide the voltage in half.
One resistor (the top resistor) having twice the resistance of the
other, will divide the voltage to a third. If the top resistor is
nine times the bottom resistor, the divider produces one tenth. And
so on and so forth...

###### Asked in Electronics Engineering, Electrical Engineering

### How do design a high voltage voltmeter?

Use a voltage divider and an standard high input impedance
voltmeter connected to the low voltage output tap of the divider.
Just check that:
a) the voltage divider has enough resistance to minimize loading
of the voltage source (The voltage divider resistance should be as
high as possible).
b) the voltmeter's input impedance is at least 10-20 times
larger than the output resistance (impedance) of the divider. If
necessary add a high-input impedance amplifier or a transducer
between the divider output and the voltmeter.
What is high voltage for you?