Working of Bleeder Resistor
The operation of an inductor filter is based on the fact that a minimum current flows through it at all times. To provide flow of this minimum current at all times through the choke, a resistor called BLEEDER RESISTOR is placed across the filter output.
Figure shows the Circuit Diagram of BLEEDER RESISTOR
Thus it is used to maintain a certain minimum current through the choke, even the load resistor gets open circuited, and improves the filtering action.
Advantages of Bleeder Resistor
- It improves the Voltage regulation. Being connected permanently across the supply it causes an initial Voltage drop and on connecting the load their is a slightly additional voltage drop. Thus the Difference between the no load voltage and full load voltage is reduced thereby increasing the voltage Regulation.
- It provides the safety to the operator by providing a discharge path to the capacitor.
When Power supply is switched off the filter capacitor discharges through it.
That is why it is called BLEEDER RESISTOR.
- Bleeder Resistor can be used as Voltage Divider, for tapping out any desired output Voltage. In this case the bleeder Resistor may two or more Resistors connected in series.