A control loop circuit for charger

Abstract

The present invention discloses a control loop circuit for a charger, including a constant current control loop circuit and a constant voltage control loop circuit that move in parallel, wherein the constant current control loop circuit and the constant voltage control loop circuit are connected to the COM terminal through two diodes to finally control the output, and is characterized in that the constant current control loop circuit includes a constant current control circuit and an additional voltage control loop circuit; the output end output Vref of the constant current control circuit is given as the input of the additional voltage control loop circuit. The present invention adds an additional voltage control loop circuit to the existing constant current control loop circuit, solving the problems of difficulty in setting constant current loop parameters and large current ripple in the existing charger control circuit, which usually adopts a dual-loop competition mode, that is, the constant current control loop and the constant voltage control loop are operated in parallel.

Description

Technical Field

[0001] The present invention relates to the technical field of chargers, and in particular to a control loop circuit applied to a charger. Background Art

[0002] In conventional charger control circuits, a dual-loop competition method is usually adopted, that is, the constant current control loop circuit and the constant voltage control loop circuit are operated in parallel, such as Figure 1 As shown, operational amplifier U1, resistor R1, capacitors C1 and C2 form a constant current control loop circuit, Io is the output current feedback, and Iref is the output current setting. Operational amplifier U2, resistor R2, capacitors C3 and C4 form a constant voltage control loop circuit, Vo is the output voltage feedback, and CVref is the output constant voltage setting. The constant current control loop circuit and the constant voltage control loop circuit are connected to the COM terminal through diodes D1 and D2 to control the output. The two loops realize constant current and constant voltage control of charging through simple parallel connection.

[0003] The above control method has problems such as difficulty in setting constant current loop parameters and large current ripple. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a control loop circuit for a charger in view of the problems existing in the existing charger control circuit, which usually adopts a dual-loop competition mode, that is, the constant current control loop and the constant voltage control loop are operated in parallel, such as the difficulty in setting the constant current loop parameters and the large current ripple.

[0005] The technical problem to be solved by the present invention can be achieved by the following technical solutions:

[0006] A control loop circuit applied to a charger, comprising a constant current control loop circuit and a constant voltage control loop circuit moving in parallel, wherein the constant current control loop circuit and the constant voltage control loop circuit are connected to a COM terminal through two diodes to finally control the output, and characterized in that the constant current control loop circuit comprises a constant current control circuit and an additional voltage control loop circuit; the output end of the constant current control circuit outputs Vref as an input given by the additional voltage control loop circuit.

[0007] In a preferred embodiment of the present invention, the additional voltage control loop circuit is composed of an operational amplifier, a first resistor, a first capacitor, and a second capacitor. The first resistor is connected in series with the first capacitor and then connected in parallel with the second capacitor to the first input and output terminals of the operational amplifier; the output terminal of the constant current control circuit outputs Vref as an input given by the operational amplifier in the additional voltage control loop circuit.

[0008] Due to the adoption of the above technical solution, the present invention adds an additional voltage control loop circuit to the existing constant current control loop circuit, thereby solving the problems of difficulty in setting constant current loop parameters and large current ripple existing in the existing charger control circuit, which usually adopts a dual-loop competition method, that is, the constant current control loop and the constant voltage control loop operate in parallel. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 The present invention is a schematic diagram of the electrical principle of a constant current control loop circuit and a constant voltage control loop circuit operating in parallel in an existing charger control circuit.

[0010] Figure 2 The figure is a schematic diagram of the electrical principle of the control loop circuit of the charger applied to the present invention. DETAILED DESCRIPTION

[0011] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0012] See also Figure 2 The control loop circuit shown in the figure is applied to a charger, including a constant current control loop circuit and a constant voltage control loop circuit moving in parallel. The constant current control loop circuit and the constant voltage control loop circuit are connected to the COM terminal through two diodes D1 and D2 to finally control the output.

[0013] The constant current control loop circuit includes a constant current control circuit and an additional voltage control loop circuit, wherein:

[0014] Operational amplifier U1, resistor R1, capacitors C1 and C2 constitute a constant current control circuit, Io is the output current feedback, and Iref is the output current given.

[0015] The operational amplifier U2, resistors R2, R3, R4, and capacitors C3 and C4 form an additional voltage control loop circuit, Vo is the output voltage feedback, and the output Vref of the operational amplifier U1 is given as the input of the additional voltage control loop, thereby reconstructing the constant current control loop.

[0016] Operational amplifier U3, resistors R5, R6, capacitors C5, C6 form a constant voltage control loop circuit, Vo is the output voltage feedback, CVref is the output constant voltage setting; finally, the additional voltage control loop is connected to the constant voltage control loop through diodes D1, D2 and connected to the COM terminal to finally control the output.

Claims

1. A control loop circuit for a charger, comprising a constant current control loop circuit and a constant voltage control loop circuit in parallel, wherein the constant current control loop circuit and the constant voltage control loop circuit are connected to the COM terminal through the positive electrodes of two diodes to control the output, characterized in that: The constant current control loop circuit comprises a constant current control circuit and an additional voltage control loop circuit connected in series; the output terminal of the constant current control circuit outputs Vref as an input given by the additional voltage control loop circuit.

2. A control loop circuit for a charger as claimed in claim 1, characterized in that: The additional voltage control loop circuit is composed of an operational amplifier, a first resistor, a first capacitor, and a second capacitor. The first resistor is connected in series with the first capacitor and then connected in parallel with the second capacitor to the first input and output terminals of the operational amplifier. The output terminal of the constant current control circuit outputs Vref as an input given by the operational amplifier in the additional voltage control loop circuit.

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