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What is series pass regulator?
The series voltage regulator or series pass voltage regulator uses a variable element placed in series with the load. Instead of drawing the current not required by the load to maintain the voltage, it drops the voltage difference between the input voltage and the required stabilised voltage.
What is the function of series pass transistor?
When a transistor is used primarily not as an amplifier but as an “analog gate” which controls the current flowing through it, it is called sometimes “series pass transistor” . A classic example is a linear voltage regulator (LDO) in which a transistor controls the current which produces the output voltage.
What does voltage regulator do?
Voltage regulator, any electrical or electronic device that maintains the voltage of a power source within acceptable limits. The voltage regulator is needed to keep voltages within the prescribed range that can be tolerated by the electrical equipment using that voltage.
How does a series pass voltage regulator work?
The series voltage regulator or series pass voltage regulator uses a variable element placed in series with the load. By changing the resistance of the series element, the voltage dropped across it can be varied to ensure that the voltage across the load remains constant.
Which is the series pass transistor TR1 or TR2?
In this circuit TR1 forms the series pass transistor. The second transistor, TR2 acts as the differential amplifier, feeding the error voltage between the reference diode and the sensed output voltage which is a proportion of the output voltage as set by the potentiometer.
How is a transistor series voltage regulator biased?
The circuit of a transistor series voltage regulator with foldback current limiting facility is illustrated in the figure. In this circuit base of transistor Q 3 is biased by a voltage divider network consisting of resistors R 6 and R 7. The load current I L flows through resistor R 5, causing a voltage drop of I l R 5 (approximately) across it.
What is the main function of a transistor current regulator?
Transistor current regulator using a Zener diode and a PNP transistor is shown in the figure below. The main function of this regulator is to maintain a fixed current through the load despite changes in terminal voltage. Suppose due to increase in output voltage V out load current I L increases.