How do you increase the output current of a regulator?

How do you increase the output current of a regulator?

An outboard pass transistor used to increase the current output of a voltage regulator IC. Although the 78xx series of voltage regulators are available with different current outputs, you can boost the available current output with this circuit.

Which transistor is used in voltage regulator?

The output voltage of the stabilizer is equal to the Zener diode voltage minus the base–emitter voltage of the transistor, UZ − UBE, where UBE is usually about 0.7 V for a silicon transistor, depending on the load current.

What controls the voltage output of a linear regulator?

A linear regulator employs an active (BJT or MOSFET) pass device (series or shunt) controlled by a high gain differential amplifier. It compares the output voltage with a precise reference voltage and adjusts the pass device to maintain a constant output voltage.

Why transistor is used in voltage regulator?

Transistor Series Voltage Regulator. This regulator has a transistor in series to the Zener regulator and both in parallel to the load. The transistor works as a variable resistor regulating its collector emitter voltage in order to maintain the output voltage constant.

How do you increase the output current of 7805?

In the following circuit to increase 7805 output current up to 3 amperes, must be added a complementary NPN transistor MJ2955. The advantage of this technique is to overcome when there is short-circuit as described above. When there is a voltage drop, then the circuit will reduce the maximum current consumption.

How can we increase the output current of 7812?

High current 7812 voltage regulator circuit can be constructed by adding a transistor to increase load current capability. As contained in the manual 78/79xx three terminal voltage regulators, positive type of regulator used to use NPN transistors, and otherwise negative type use PNP transistors.

What is current booster circuit?

The power transistor is used to boost the extra needed current above the maximum allowable current provided via the regulator. Current up to 1500mA(1.5amp) will flow through the regulator, anything above that makes the regulator conduct and adding the extra needed current to the output load.

How is the load resistor set in a voltage regulator?

To correctly set the load resistor value depending on the output current and the input supply, the following data can be applied appropriately. Suppose the required output voltage is 5V, the required current is 20 mA, and the supply input is 12 V. Then using Ohms law we have:

How is a linear voltage regulator used in ref?

The linear regulator in Ref. utilized a high-slew-rate amplifier with a push–pull output stage to improve transient response while consuming low quiescent current to increase light-load efficiency.

How does the resistance of a series regulator work?

The resistance of the transistor to current automatically adjusts depending on the output load, such that the output voltage remains constant at the desired level. In a series regulator circuit the input current has to be slightly more than the output current.

How is error signal generated in linear voltage regulator?

A portion of the output voltage, VDD, is sensed through the resistive dividers, R1 and R2, and compared to the reference voltage, VREF. The error amplifier generates a corresponding error signal, VEA, to adaptively control the voltage drop across the pass transistor by adjusting its gate voltage.