Continuous adjustable DC stabilized power supply circuit with 0V minimum output voltage based on three terminal regulator

Abstract

The invention discloses a continuous adjustable DC stabilized power supply circuit with 0V minimum output voltage based on a three terminal regulator. The circuit comprises a three terminal regulator and a load. The anode of a filtering capacitor C1 is connected with the anode output end of an external input power supply and the input end Vin of the three terminal regulator. The cathode of the filtering capacitor C1 is connected with a power ground GND. One end of an adjustable resistor R2 is connected with the adjusting end ADJ of the three terminal regulator. The other end of the adjustable resistor R2 is connected with the power ground GND. One end of a divider resistor R1 is connected with the adjusting end ADJ of the three terminal regulator, and the other end is connected with the output end Vout of the three terminal regulator. The anode of a diode D1 is connected with the output end Vout of the three terminal regulator, and the cathode of the diode D1 is connected with the anode of a diode D2. The cathode of the diode D2 is connected with the anode of the filtering capacitor C2. The cathode of the filtering capacitor C2 is connected with the power ground GND. Two ends of the load are respectively connected with two ends of the filtering capacitor C2. The circuit has beneficial effect of 0V minimum output voltage and is continuous adjustable.

Description

technical field [0001] The invention relates to a circuit, in particular to a continuously adjustable DC stabilized voltage power supply circuit based on the minimum output voltage 0V of a three-terminal voltage stabilizer. Background technique [0002] A circuit that can maintain a constant output voltage when the input voltage, load, ambient temperature, circuit parameters, etc. change. This circuit can provide a stable DC power supply and is widely used in various electronic devices. [0003] At present, the DC regulated power supply designed with integrated voltage regulator has many advantages such as stable performance and simple structure. Among them, the adjustable three-terminal voltage regulator is widely used, and it not only has the simplest form of fixed three-terminal voltage regulator circuit , It also has the characteristics of continuously adjustable voltage output of the stabilized voltage. Including two types of three-terminal voltage regulators with pos...

AI Technical Summary

Problems solved by technology

[0004] Although the three-terminal voltage regulator with positive voltage and negative voltage output functions has the characteristics of continuously adjustable voltage output, but the reference voltage inside the three-terminal voltage regulator (generally greater than 1.25V), if no other auxiliary circuit, then the output voltage of this type of three-terminal regulator cannot be lower than the reference voltage

In this way, it means that the three-terminal voltage regulator cannot output 0V DC voltage

[0005] To solve the 0V output of the regulated DC power supply based on the design of the three-terminal voltage regulator, the common solution is to change the input voltage of the three-terminal voltage regulator by adding auxiliary active or passive circuits, and set the limit on the adjustment voltage pin. Voltage circuit, so as to achieve the function of outputting 0V based on the three-terminal voltage regulator. The circuit implementation of the above measures is generally cumbersome and has certain limitations.

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