How does a discharge resistor work?
Therefore, to discharge the capacitor after the supply has been turned off, a large-value resistor is connected across its terminals. After it is switched off, the charge on the capacitor will drain off through this “bleeder resistor”, causing the voltage to decay quickly to safe levels.
When would you use a bleeder resistor?
A bleeder resistor is a standard resistor connected in parallel with the output of a high-voltage power supply circuit for the purpose of discharging the electric charge stored in the power supply’s filter capacitors when the equipment is turned OFF. This is done for safety reasons.
How do you calculate bleeder current?
The bleeder current should be 10\% of the total load current. Since the voltage across R1 (ER1) is equal to the voltage requirement for load 1, Ohm’s law can be used to calculate the value for R1. The current through R2 (IR2) is equal to the current through R1 plus the current through load 1.
How do you choose a bleeder resistor?
To select a suitable bleeder resistor, you can consider the relationship between the momentary voltage across the capacitor Vt, the bleeder resistance R for discharge, the initial voltage Vu. t is the momentary period and the total capacitor capacitance is C.
How a capacitor discharges through a resistor?
A capacitor with capacitance 0.1F in an RC circuit is initially charged up to an initial voltage of Vo = 10V and is then discharged through an R=10Ω resistor as shown. After one time constant, the voltage, charge, and current have all decreased by a factor of e. After two time constants, everything has fallen by e2.
Do resistors have direction?
Resistors are blind to the polarity in a circuit. Current can pass equally through a resistor in either direction. In schematic diagrams, a resistor is represented by a jagged line, like the one shown in the margin. The resistance value is typically written next to the resistor symbol.