A simplified ac detection circuit

Abstract

This utility model discloses a simplified AC detection circuit connected to the AC power input terminal. It includes a 43rd resistor, a 44th resistor, a 45th resistor, and a third optocoupler. The 43rd, 44th, and 45th resistors are connected in series to form a step-down current-limiting circuit. One end of the step-down current-limiting circuit is connected to the positive terminal of the AC power input terminal, and the other end is connected to the positive terminal of the LED in the third optocoupler. The negative terminal of the LED in the third optocoupler is connected to the negative terminal of the AC power input terminal. The positive terminal of the output of the third optocoupler is connected to the detection pin of the MCU control circuit, and the negative terminal of the output of the third optocoupler is grounded. This utility model has a reasonable structural design, uses fewer electronic components, and eliminates the need for a rectifier circuit and circuits drawing power from VCC, which helps reduce manufacturing costs and improves operational stability and reliability.

Description

Technical Field

[0001] This utility model belongs to the field of driving power supply technology, and specifically relates to a simplified AC detection circuit. Background Technology

[0002] LED lighting fixtures are generally equipped with corresponding driving circuits, and in order to ensure the stable operation of the driving circuits, corresponding AC detection circuits are set up. Existing AC detection circuits are very complex. For example, a fire protection power supply containing an AC detection circuit as shown in CN201821514076.6 uses a lot of electronic components, which greatly increases the overall circuit usage cost and design cost, making it difficult to meet market demands. Utility Model Content

[0003] The purpose of this invention is to provide a simplified AC detection circuit with a reasonable structural design that helps reduce costs.

[0004] The technical solution to achieve the purpose of this utility model is a simplified AC detection circuit, which is connected to the AC power input terminal and includes a forty-third resistor, a forty-fourth resistor, a forty-fifth resistor, and a third optocoupler.

[0005] The forty-third resistor, the forty-fourth resistor, and the forty-fifth resistor are connected in series to form a step-down current-limiting circuit;

[0006] One end of the step-down current limiting circuit is connected to the positive terminal of the AC power input, and the other end is connected to the positive terminal of the light-emitting diode in the third optocoupler.

[0007] The negative terminal of the light-emitting diode in the third optocoupler is connected to the negative terminal of the AC power input.

[0008] The positive terminal of the third optocoupler is connected to the detection pin of the MCU control circuit, and the negative terminal of the third optocoupler is grounded.

[0009] A further preferred embodiment is that an eighth unidirectional diode is fixed between the positive and negative terminals of the light-emitting diode in the third optocoupler, the positive terminal of the eighth unidirectional diode is connected to the negative terminal of the light-emitting diode in the third optocoupler, and the negative terminal of the eighth unidirectional diode is connected to the positive terminal of the light-emitting diode in the third optocoupler.

[0010] Its working principle is briefly described as follows: When powered on normally, the circuit limits and reduces the voltage of AC1 and AC2 through R43, R44 and R45. D8 is reverse cut off and directly forms a 50HZ positive rotation signal with the AK terminal of B3, which is then used by the MCU and other devices that need it.

[0011] This utility model has positive effects: the structure of this utility model is reasonable, the number of electronic components used in its overall structure is small, and the rectifier circuit and the circuit for drawing power from VCC are eliminated, which helps to reduce processing costs, improves the stability and reliability of use, and has strong applicability. Attached Figure Description

[0012] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein:

[0013] Figure 1 This is a schematic diagram of the specific circuit of this utility model;

[0014] Figure 2 This is a schematic diagram of the specific circuit when the present invention is used in a driving power supply.

[0015] Figure labeling: 1. AC power input terminal, 2. step-down current limiting circuit, 3. rectifier filter circuit, 4. step-down voltage regulator circuit, 5. MCU control circuit, 6. drive circuit. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] Example

[0018] See Figures 1 to 2 As shown, a simplified AC detection circuit, connected to the AC power input terminal 1, includes a 43rd resistor R43, a 44th resistor R44, a 45th resistor R45, and a third optocoupler B3. The 43rd resistor R43, the 44th resistor R44, and the 45th resistor R45 are connected in series to form a step-down current-limiting circuit 2. During connection, one end of the step-down current-limiting circuit 2 is connected to the positive terminal of the AC power input terminal 1, and the other end is connected to the positive terminal of the LED in the third optocoupler B3. The negative terminal of the LED in the third optocoupler B3 is connected to the negative terminal of the AC power input terminal 1. The positive terminal of the output terminal of the third optocoupler B3 is connected to the detection pin of the MCU control circuit, and the negative terminal of the output terminal of the third optocoupler is grounded. Using this circuit eliminates the need for a rectifier circuit and circuits that draw power from VCC, thus reducing manufacturing costs. Furthermore, since it does not require power from VCC, it is easier to assemble and use, and also facilitates maintenance and operation.

[0019] Furthermore, an eighth unidirectional diode D8 is fixed between the positive and negative terminals of the light-emitting diode in the third optocoupler. The positive terminal of the eighth unidirectional diode is connected to the negative terminal of the light-emitting diode in the third optocoupler, and the negative terminal of the eighth unidirectional diode is connected to the positive terminal of the light-emitting diode in the third optocoupler.

[0020] Its working principle is briefly described as follows: When powered on normally, the circuit limits and reduces the voltage of AC1 and AC2 through R43, R44 and R45. D8 is reverse cut off and directly forms a 50HZ positive rotation signal with the AK terminal of B3, which is then used by the MCU and other devices that need it.

[0021] exist Figure 2 In this combination, it is used in the driving power supply, which includes a rectifier and filter circuit 3, a step-down voltage regulator circuit 4, an MCU control circuit 5, and a driving circuit 6 connected to the AC power input terminal. The above circuits are all conventional structures of the prior art, and are simply applied, so they are not described in detail.

[0022] This utility model has positive effects: the structure of this utility model is reasonable, the number of electronic components used in its overall structure is small, and the rectifier circuit and the circuit for drawing power from VCC are eliminated, which helps to reduce processing costs, improves the stability and reliability of use, and has strong applicability.

[0023] The standard parts used in this embodiment can be purchased directly from the market, and the non-standard structural parts described in the instruction manual can also be processed without any doubt based on existing technical common sense. At the same time, the connection methods of each component adopt mature conventional methods in the existing technology, and the machinery, parts and equipment all adopt conventional models in the existing technology, so they will not be described in detail here.

[0024] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating this utility model, and are not intended to limit the implementation of this utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all embodiments here. However, these obvious variations or modifications derived from the essential spirit of this utility model still fall within the protection scope of this utility model.

Claims

1. A simplified AC detection circuit, connected to the AC power input terminal, characterized in that: Including resistors 43, 44, and 45, and the third optocoupler; The forty-third resistor, the forty-fourth resistor, and the forty-fifth resistor are connected in series to form a step-down current-limiting circuit; One end of the step-down current limiting circuit is connected to the positive terminal of the AC power input, and the other end is connected to the positive terminal of the light-emitting diode in the third optocoupler. The negative terminal of the light-emitting diode in the third optocoupler is connected to the negative terminal of the AC power input. The positive terminal of the third optocoupler is connected to the detection pin of the MCU control circuit, and the negative terminal of the third optocoupler is grounded.

2. The simplified AC detection circuit according to claim 1, characterized in that: An eighth unidirectional diode is fixed between the positive and negative terminals of the light-emitting diode in the third optocoupler. The positive terminal of the eighth unidirectional diode is connected to the negative terminal of the light-emitting diode in the third optocoupler, and the negative terminal of the eighth unidirectional diode is connected to the positive terminal of the light-emitting diode in the third optocoupler.

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