CN205039703U - Intelligence step -down formula switching power supply - Google Patents

Abstract

The utility model discloses an intelligent step-down switching power supply, which comprises a resistor R1, an inductor L1, a capacitor C1, a diode D1, a three-terminal voltage regulator U1, a triode VT1 and a diode D1, one end of the resistor R1 is connected to a power supply VCC, and the other end of the resistor R1 is One end is respectively connected to the capacitor C1, the emitter of the triode VT1, the cathode of the diode D1 and the S pole of the MOS transistor Q1, the G pole of the MOS transistor Q1 is respectively connected to the anode of the diode D1, the collector of the triode VT1 and the resistor R2, and the D pole of the MOS transistor Q1 is respectively connected to Capacitor C2, diode D2 cathode and inductor L1, the other end of capacitor C2 is respectively connected to the base of triode VT1, capacitor C5 and resistor R3, and the other end of resistor R3 is respectively connected to the other end of capacitor C5 and the collector of triode VT2. The intelligent step-down switching power supply of the utility model is controlled by a triode and a MOS tube. The circuit structure is simple, the cost is low, and the volume is small, which is very suitable for popularization and use.

Description

An Intelligent Step-Down Switching Power Supply

technical field

The utility model relates to a switching power supply, in particular to an intelligent step-down switching power supply.

Background technique

Switching power supply is known as high-efficiency and energy-saving power supply. It is an ideal product under the modern advocacy of green environmental protection. It represents the development direction of regulated power supply and has become the mainstream product of regulated power supply. In the switch state, the energy consumption itself is very low, and the power supply efficiency can reach 70% to 90%, which is nearly double that of ordinary linear regulated power supplies. Switching power supply is also called power supply without power frequency transformer. It uses a small high-frequency transformer to realize voltage conversion and grid isolation. It can not only remove the heavy power frequency transformer, but also use smaller filter components and heat dissipation. Research and development of switching power supplies with high efficiency, high density, high reliability, small size and light weight have become the direction of people's research.

Utility model content

The purpose of this utility model is to provide an intelligent step-down switching power supply to solve the problems raised in the above-mentioned background technology.

In order to achieve the above object, the utility model provides the following technical solutions:

An intelligent step-down switching power supply, comprising a resistor R1, an inductor L1, a capacitor C1, a diode D1, a three-terminal voltage regulator U1, a transistor VT1 and a diode D1, one end of the resistor R1 is connected to the power supply VCC, and the other end of the resistor R1 is respectively connected to The capacitor C1, the emitter of the triode VT1, the cathode of the diode D1 and the S pole of the MOS transistor Q1, the G pole of the MOS transistor Q1 are respectively connected to the positive pole of the diode D1, the collector of the triode VT1 and the resistor R2, and the D pole of the MOS transistor Q1 is respectively connected to the capacitor C2, The cathode of diode D2 and inductor L1, the other end of capacitor C2 are respectively connected to the base of triode VT1, capacitor C5 and resistor R3, the other end of resistor R3 is respectively connected to the other end of capacitor C5 and the collector of triode VT2, and the emitter of triode VT2 is connected to the other end of capacitor C1 , the other end of the resistor R2, the positive pole of the diode D2, the resistor R4, the resistor R6, the capacitor C3, the ground terminal of the three-terminal voltage regulator U1 and the capacitor C4 and ground, the base of the triode VT2 is respectively connected to the other end of the resistor R6 and the resistor R5, and the resistor R5 is separately One end is respectively connected to the other end of the inductor L1, the other end of the resistor R4, the other end of the capacitor C3 and the input end of the three-terminal regulator U1, and the output end of the three-terminal voltage regulator U1 is respectively connected to the output terminal Vo and the other end of the capacitor C4.

As a further solution of the utility model: the three-terminal regulator U1 adopts 7805.

As a further solution of the present invention: the diode D1 is a Zener diode.

As a further solution of the utility model: the voltage of the power supply VCC is 12V.

Compared with the prior art, the beneficial effect of the utility model is that the intelligent step-down switching power supply of the utility model is controlled by triode and MOS tube, the circuit structure is simple, the cost is low, the volume is small, and it is very suitable for popularization and use.

Description of drawings

Figure 1 is a circuit diagram of an intelligent step-down switching power supply.

detailed description

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Please refer to Fig. 1, in the embodiment of the utility model, an intelligent step-down switching power supply includes a resistor R1, an inductor L1, a capacitor C1, a diode D1, a three-terminal voltage regulator U1, a triode VT1 and a diode D1, and one end of the resistor R1 Connect the power supply VCC, the other end of the resistor R1 is respectively connected to the capacitor C1, the emitter of the triode VT1, the cathode of the diode D1 and the S pole of the MOS transistor Q1, and the G pole of the MOS transistor Q1 is respectively connected to the anode of the diode D1, the collector of the triode VT1 and the resistor R2, MOS The D pole of the tube Q1 is respectively connected to the capacitor C2, the negative pole of the diode D2 and the inductor L1, the other end of the capacitor C2 is respectively connected to the base of the triode VT1, the capacitor C5 and the resistor R3, and the other end of the resistor R3 is respectively connected to the other end of the capacitor C5 and the collector of the triode VT2, The emitter of the triode VT2 is connected to the other end of the capacitor C1, the other end of the resistor R2, the positive pole of the diode D2, the resistor R4, the resistor R6, the capacitor C3, the ground terminal of the three-terminal voltage regulator U1 and the capacitor C4 and grounded, and the base of the triode VT2 is connected to the resistor The other end of R6 and resistor R5, the other end of resistor R5 are respectively connected to the other end of inductor L1, the other end of resistor R4, the other end of capacitor C3 and the input end of three-terminal voltage regulator U1, and the output end of three-terminal voltage regulator U1 is respectively connected to the output End Vo and the other end of capacitor C4.

The three-terminal voltage regulator U1 uses 7805.

Diode D1 is a Zener diode.

The power supply VCC voltage is 12V.

The working principle of this utility model is: please refer to Fig. 1, at the instant when the circuit is started, the power supply provides sufficient G pole current to Q1 through R2, Q1 is saturated and turned on, and Q1 can use a P-type MOS tube, and a part of its D pole current Charge C3 through L1 and provide it to the output terminal Vo, and a part is stored in L1. When the voltage across C3 exceeds 15V, VT2 is turned on, and VT1 is also turned on, causing the G electrode potential of Q1 to rise, and the current to decrease. The potential of the upper end of C2 Since the voltage across C2 cannot change abruptly, the base potential of VT1 drops rapidly, and the base potential of Q1 rises rapidly until it is turned off quickly. After Q1 is turned off, the energy stored in L1 is released to C3 and the output terminal Vo through the freewheeling diode D2 , and then start the next cycle of the cycle.

It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from all points of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, so it is intended to fall within the scope of the claims All changes within the meaning and range of equivalents of the required elements are included in the present invention. Any reference sign in a claim should not be construed as limiting the claim concerned.

In addition, it should be understood that although this specification is described according to implementation modes, not each implementation mode only contains an independent technical solution, and this description in the specification is only for clarity, and those skilled in the art should take the specification as a whole , the technical solutions in the various embodiments can also be properly combined to form other implementations that can be understood by those skilled in the art.

Claims (4)

1. An intelligent step-down switching power supply, comprising a resistor R1, an inductor L1, a capacitor C1, a diode D1, a three-terminal voltage regulator U1, a triode VT1 and a diode D1, wherein one end of the resistor R1 is connected to a power supply VCC, The other end of the resistor R1 is respectively connected to the capacitor C1, the emitter of the triode VT1, the cathode of the diode D1 and the S pole of the MOS transistor Q1. The poles are respectively connected to the capacitor C2, the negative pole of the diode D2 and the inductor L1, the other end of the capacitor C2 is respectively connected to the base of the triode VT1, the capacitor C5 and the resistor R3, and the other end of the resistor R3 is respectively connected to the other end of the capacitor C5 and the collector of the triode VT2, and the emitter of the triode VT2 Connect the other end of the capacitor C1, the other end of the resistor R2, the positive pole of the diode D2, the resistor R4, the resistor R6, the capacitor C3, the ground terminal of the three-terminal regulator U1, and the capacitor C4 to ground, and the base of the triode VT2 is connected to the other end of the resistor R6 and Resistor R5 and the other end of resistor R5 are respectively connected to the other end of the inductor L1, the other end of the resistor R4, the other end of the capacitor C3 and the input end of the three-terminal voltage regulator U1, and the output end of the three-terminal voltage regulator U1 is respectively connected to the output end Vo and the capacitor The other end of C4. 2. The intelligent step-down switching power supply according to claim 1, wherein the three-terminal regulator U1 is a 7805. 3. The intelligent step-down switching power supply according to claim 1, wherein the diode D1 is a Zener diode. 4. The intelligent step-down switching power supply according to claim 1, wherein the voltage of the power supply VCC is 12V.