A DC boost circuit based on complementary resonance

Abstract

The utility model relates to a DC boost circuit based on complementary resonance, and belongs to the technical field of voltage conversion. It includes a first resistor, a second resistor, a first transistor, a second transistor, a third transistor, a first capacitor, a second capacitor, a first inductor and a first diode; the emitter of the first transistor is connected to the 2nd pin of the first inductor and the power supply, the base of the first transistor is connected to the 1st pin of the second resistor and the 2nd pin of the first capacitor, the collector of the first transistor is connected to the base of the second transistor through the first resistor; the collector of the second transistor is connected to the 1st pin of the first capacitor, the 1st pin of the first inductor and the anode of the first diode, and the emitter of the second transistor is grounded; the cathode of the first diode and the 1st pin of the second capacitor are connected to the positive electrode of the load; the 2nd pin of the second capacitor and the emitter of the third transistor are grounded, the 2nd pin of the first resistor is connected to the collector of the third transistor, and the base of the third transistor is connected to the negative electrode of the load.

Description

Technical Field

[0001] The utility model relates to a DC boost circuit based on complementary resonance, belonging to the technical field of voltage conversion. Background Art

[0002] In emergency lighting products, when the AC power is off, batteries are needed to light up the LEDs. However, the battery voltage is usually too low to meet the power supply requirements of multiple LEDs, so a boost circuit is needed to boost the voltage. In the boost circuit, the control of the periodic on and off of the switch is usually done by a single-chip microcomputer, which not only increases the difficulty of product development, but also increases the development cost. In order to reduce the development cost and the complexity of the circuit, it is the best choice not to use a single-chip microcomputer control. Utility Model Content

[0003] In order to solve the control problem caused by a system without a single-chip microcomputer, the utility model provides a DC boost circuit based on complementary resonance.

[0004] The utility model is realized by the following technical scheme: a DC boost circuit based on complementary resonance, characterized in that: it comprises a first resistor, a second resistor, a first transistor, a second transistor, a third transistor, a first capacitor, a second capacitor, a first inductor and a first diode; the emitter of the first transistor is connected to the 2nd foot of the first inductor and the power supply, the base of the first transistor is connected to the 1st foot of the second resistor and the 2nd foot of the first capacitor, the collector of the first transistor is connected to the base of the second transistor through the first resistor; the collector of the second transistor is connected to the 1st foot of the first capacitor, the 1st foot of the first inductor and the anode of the first diode, and the emitter collector of the second transistor is grounded; the cathode of the first diode and the 1st foot of the second capacitor are connected to the positive electrode of the load; the 2nd foot of the second capacitor and the emitter of the third transistor are grounded, the 2nd foot of the first resistor is connected to the collector of the third transistor, and the base of the third transistor is connected to the negative electrode of the load.

[0005] The first transistor and the second transistor are turned on or turned off at the same time.

[0006] The third transistor is turned on when connected to a load, and the circuit works and outputs normally; and is turned off when not connected to a load, and the circuit stops working.

[0007] The beneficial effects of the utility model are as follows: a single-chip microcomputer can be replaced by only two transistors, a resistor and a feedback capacitor to realize the control of the periodic on and off of the switch, and the time is adjustable, which reduces the development cost and difficulty, solves the control problem caused by the absence of a single-chip microcomputer in a simple electronic circuit, and at the same time, the circuit works normally when there is a load and stops working when there is no load, avoiding waste of electricity. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The utility model is further described below based on the drawings and embodiments.

[0009] Figure 1 It is a circuit principle diagram of the utility model. DETAILED DESCRIPTION

[0010] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0011] In the description of the present utility model, it should be noted that the orientation or position relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present utility model; the terms "first", "second", and "third" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance. In addition, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0012] like Figure 1A DC boost circuit based on complementary resonance is shown, comprising a first resistor R1, a second resistor R2, a first transistor Q1, a second transistor Q2, a third transistor Q3, a first capacitor C1, a second capacitor C2, a first inductor L1 and a first diode D1; the emitter of the first transistor Q1 is connected to the 2nd pin of the first inductor L1 and a power supply +2.5V, the base of the first transistor Q1 is connected to the 1st pin of the second resistor R2 and the 2nd pin of the first capacitor C1, and the collector of the first transistor Q1 is connected to the base of the second transistor Q2 through the first resistor R1; the collector of the second transistor Q2 is connected to the 1st pin of the first capacitor C1, the 1st pin of the first inductor L1 and the anode of the first diode D1, and the emitter collector of the second transistor Q2 is grounded; the cathode of the first diode D1 and the 1st pin of the second capacitor C2 are connected to the positive electrode Vout of the load; the 2nd pin of the second capacitor C2 and the emitter of the third transistor Q3 are grounded, the 2nd pin of the first resistor R1 is connected to the collector of the third transistor Q3, and the base of the third transistor Q3 is connected to the negative electrode of the load.

[0013] The first transistor Q1 is a PNP transistor, model SS8550.

[0014] The second transistor Q2 and the third transistor Q3 are NPN transistors, and the model is MMSS8050.

[0015] The first transistor Q1 and the second transistor Q2 are turned on or turned off at the same time.

[0016] The third transistor Q3 is turned on when connected to a load, and the circuit works and outputs normally; it is turned off when not connected to a load, and the circuit stops working.

[0017] When a load is connected and the +2.5V power supply is provided, the third transistor Q3 is turned on, the second resistor R2 provides a base start-up current to the first transistor Q1, the first transistor Q1 is slowly turned on, the second transistor Q2 is also slowly turned on, and a charging circuit is provided for the first capacitor C1; the base current of the first transistor Q1 increases significantly, the first transistor Q1 is saturated and turned on, the second transistor Q2 is also saturated and turned on, and the first capacitor C1 starts to charge through the base and emitter of Q1, the 2nd and 1st pins of the first capacitor C1, the collector and emitter of the second transistor Q2, and the ground; as the first capacitor C1 is charged, the base voltage of the first transistor Q1 increases, the first transistor Q1 exits the saturated conduction state, the second transistor Q2 also exits the saturated conduction state, and the voltage across the first capacitor C1 continues to rise. Due to the positive feedback, the turn-off of the first transistor Q1 and the second transistor Q2 is accelerated. Due to the cut-off of the first transistor Q1 and the second transistor Q2, the voltage at the pin 2 of the first capacitor C1 reaches the maximum, and discharges to the ground through the collector and emitter of the second resistor R2 and the third transistor Q3. When the voltage at the pin 2 drops below 1.9V, the first transistor Q1 starts to turn on again and enters the next switching process. The first inductor L1 is charged through the collector, emitter and ground of the second crystal Q2 when the first transistor Q1 and the second crystal Q2 are turned on. When the first transistor Q1 and the second crystal Q2 are turned off, it starts to discharge and charges the second capacitor C2 through the first diode D1. At the same time, the first diode D1 prevents the second capacitor C2 from discharging to the ground. When the first transistor Q1 and the second crystal Q2 are turned on again, the first inductor L1 is charged again. This cycle continues, and a higher DC voltage can be obtained at the output end. The oscillation frequency can be changed by adjusting the value of the first capacitor C1 or the second resistor R2. When no load is connected, the circuit stops working.

[0018] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A DC boost circuit based on complementary resonance, characterized in that: It includes a first resistor, a second resistor, a first transistor, a second transistor, a third transistor, a first capacitor, a second capacitor, a first inductor and a first diode; the emitter of the first transistor is connected to the 2nd pin of the first inductor and the power supply, the base of the first transistor is connected to the 1st pin of the second resistor and the 2nd pin of the first capacitor, and the collector of the first transistor is connected to the base of the second transistor through the first resistor; The collector of the second transistor is connected to pin 1 of the first capacitor, pin 1 of the first inductor and the anode of the first diode, and the emitter of the second transistor is grounded; the cathode of the first diode and pin 1 of the second capacitor are connected to the positive electrode of the load; pin 2 of the second capacitor and the emitter of the third transistor are grounded, pin 2 of the first resistor is connected to the collector of the third transistor, and the base of the third transistor is connected to the negative electrode of the load.

2. A DC boost circuit based on complementary resonance according to claim 1, characterized in that: The first transistor is a PNP transistor, model SS8550.

3. The DC boost circuit based on complementary resonance according to claim 1, characterized in that: The second transistor and the third transistor are NPN transistors, and the model is MMSS8050.

4. The DC boost circuit based on complementary resonance according to claim 1, characterized in that: The first transistor and the second transistor are turned on or turned off at the same time.

5. The DC boost circuit based on complementary resonance according to claim 1, characterized in that: The third transistor is turned on when connected to a load, and the circuit works and outputs normally; and is turned off when not connected to a load, and the circuit stops working.

Images