Ultralow-power-consumption isolation zero-cross detection circuit

Abstract

The utility model provides an ultra-low power consumption isolation zero cross detection circuit. The ultra-low power consumption isolation zero cross detection circuit comprises a diode D210, resistors R215, R216, R217, R218, R219 and R220, a capacitor C206, a triode Q210 and an optocoupler ICZ210. The ultra-low power consumption isolation zero-cross detection circuit is simple in structure and ingenious in design, the loss of the series connection resistor of the optocoupler by the mains supply voltage is reduced by reducing the voltage supplied to the resistor, and the VCC voltage on the power supply chip is used for providing power to the series connection resistor of the optocoupler, so that the low power consumption function is realized, and the power consumption of the whole machine is improved. And the voltage on the switching power supply is fully utilized to provide electric energy for the optocoupler, and the voltage provided by the power supply is smaller than the commercial power voltage, so that the loss of a resistor connected in series with the optocoupler is low, and the low-power-consumption requirement of the product is met.

Description

Technical Field

[0001] This utility model relates to a zero-crossing detection circuit, specifically an ultra-low power isolated zero-crossing detection circuit. Background Technology

[0002] Currently, many products on the market require isolation solutions, such as water dispensers, rice cookers, and toilet seats. Most of these products require temperature and speed control, which necessitates zero-crossing signals. Common circuits use optocouplers to directly draw voltage from the mains power for zero-crossing. However, existing methods for isolating zero-crossing use an optocoupler connected in series with a resistor, drawing power directly from the mains terminals. But mains voltage is high, and the optocoupler has a certain drive current, so a resistor-based voltage reduction method is used. However, this resistor-based method has high losses, with most of the power consumed by the resistor, making it difficult to achieve low power consumption for the entire machine. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention proposes an ultra-low power isolated zero-crossing detection circuit, which can reduce the loss of the optocoupler series resistor due to the mains voltage, and utilize the VCC voltage on the power chip to provide power to the optocoupler series resistor to achieve low power consumption.

[0004] To achieve the above technical solution, this utility model provides an ultra-low power isolated zero-crossing detection circuit, including: diode D210, resistors R215, R216, R217, R218, R219, R220, capacitor C206, transistor Q210, and optocoupler ICZ210. One end of diode D210 is connected to AC power ACL-AC, and the other end of diode D210 is connected to resistor R219. The other end of resistor R219 is connected to resistor R217, and the other end of resistor R217 is connected to the base (B) of transistor Q210. The emitter (E) of transistor Q210 is connected to signal ground SGND. One end of resistor R220 is connected to the connection line between resistor R217 and the base (B) of transistor Q210, and the other end of resistor R220 is connected to... The emitter (E) of transistor Q210 is connected to signal ground (SGND). The collector (C) of transistor Q210 is connected to pin 2 of optocoupler ICZ210. Pin 1 of optocoupler ICZ210 is connected to one end of resistor R218. The other end of resistor R218 is connected to the power supply voltage VCC of the power chip. Pin 4 of optocoupler ICZ210 is connected to one end of resistors R215 and R216 respectively. The other end of resistor R215 is connected to +5V. The other end of resistor R216 is connected to the ZERO pin of the MCU. Pin 3 of optocoupler ICZ210 is grounded. One end of capacitor C206 is connected at the junction of resistors R215, R216, and pin 4 of optocoupler ICZ210. The other end of capacitor C206 is connected to pin 3 of optocoupler ICZ210 and then grounded together.

[0005] In the above technical solution, during actual operation, the AC power ACL-AC passes through diode D210 to resistors R219, R217, and R220, where they form a voltage divider. The base (B) of transistor Q210 is connected to the junction of resistors R217 and R220, drawing power. Current flows through the base of transistor Q210 to its emitter (E) and finally to signal ground SGND. At this time, the collector (C) and emitter (E) of transistor Q210 are conducting. The DC power VCC passes through resistor R218 to pin 1 of optocoupler ICZ210, and pin 2 of optocoupler ICZ210 to the collector (C) of transistor Q210. Because the collector and emitter of transistor Q210 are conducting, current flows from the emitter of transistor Q210 to signal ground SGND. At this time, current flows through pins 1 and 2 of optocoupler ICZ210, causing the internal LED to light up. A 5V DC voltage flows through resistor R215 to pin 4 of the optocoupler ICZ210. Because the internal transistor of the optocoupler ICZ210 receives light from its internal LED, the transistor conducts current to ground. One pin of resistor R216 is connected to both resistor R215 and pin 4 of the optocoupler ICZ210. High and low level signals flow through resistor R216 to the ZERO pin, and are then sent to the MCU for processing.

[0006] Preferably, this ultra-low power isolated zero-crossing detection circuit further includes a capacitor C210, which is connected in parallel with a resistor R220. One end of the capacitor C210 is connected to the base (B) terminal of the resistor R220 and the emitter (E) terminal of the transistor Q210, and the other end of the capacitor C210 is connected to the emitter (E) terminal of the transistor Q210. In actual operation, the capacitor C210 is connected in parallel across the resistor R220 for filtering, reducing signal interference.

[0007] The beneficial effects of the ultra-low power isolated zero-crossing detection circuit provided by this utility model are as follows: This ultra-low power isolated zero-crossing detection circuit has a simple structure and ingenious design. By reducing the voltage supplied to the resistor, the loss of the optocoupler series resistor due to the mains voltage is reduced. Furthermore, the VCC voltage on the power chip provides power to the optocoupler series resistor, achieving low power consumption and improving the overall power consumption of the device. It also fully utilizes the voltage on the switching power supply to provide power to the optocoupler. Because the voltage supplied by the power supply is lower than the mains voltage, the loss of the optocoupler series resistor is low, meeting the low power consumption requirements of the product. Attached Figure Description

[0008] Figure 1 This is the circuit diagram of this utility model. Detailed Implementation

[0009] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0010] Example: An ultra-low power isolated zero-crossing detection circuit.

[0011] Reference Figure 1 As shown, an ultra-low power isolated zero-crossing detection circuit includes: diode D210, resistors R215, R216, R217, R218, R219, R220, capacitors C206 and C210, transistor Q210, and optocoupler ICZ210. One end of diode D210 is connected to AC power (ACL-AC), and the other end of diode D210 is connected to resistor R219. The other end of resistor R219 is connected to resistor R217. Resistor R217... The other end is connected to the base (B) of transistor Q210, and the emitter (E) of transistor Q210 is connected to signal ground (SGND). One end of resistor R220 is connected to the connection line between resistor R217 and the base (B) of transistor Q210, and the other end of resistor R220 is connected to the connection line between the emitter (E) of transistor Q210 and signal ground (SGND). Resistors R219, R217, and R220 act as a voltage divider. Capacitor C210 is connected in parallel with resistor R220, and one end of capacitor C210 is connected to... On the connection line between resistor R220 and the base (B) terminal of transistor Q210, the other end of capacitor C210 is connected to the connection line between resistor R220 and the emitter (E) terminal of transistor Q210. In actual operation, capacitor C210 is connected in parallel across resistor R220 for filtering, reducing signal interference. The collector (C) terminal of transistor Q210 is connected to pin 2 of optocoupler ICZ210, and pin 1 of optocoupler ICZ210 is connected to one end of resistor R218. The other end of resistor R218 is connected to the power supply voltage VCC of the power chip. For the connection, pin 4 of the optocoupler ICZ210 is connected to one end of resistors R215 and R216 respectively. The other end of resistor R215 is connected to +5V voltage, and the other end of resistor R216 is connected to the ZERO pin of the MCU. Pin 3 of the optocoupler ICZ210 is grounded. One end of capacitor C206 is connected to the junction of resistors R215, R216 and pin 4 of the optocoupler ICZ210. The other end of capacitor C206 is connected to pin 3 of the optocoupler ICZ210 and then grounded together.

[0012] In this embodiment, during actual operation, the AC power ACL-AC passes through diode D210 to resistors R219, R217, and R220, where they form a voltage divider. The base (B) of transistor Q210 is connected to the pins of resistors R217 and R220 for power. Current flows through the base of transistor Q210 to the emitter (E) and finally to signal ground SGND. At this time, the collector (C) and emitter (E) of transistor Q210 are connected.

[0013] The DC power supply VCC from the power chip flows through resistor R218 to pin 1 of optocoupler ICZ210. Pin 2 of optocoupler ICZ210 then flows to the collector (C) of transistor Q210. Because the collector (C) and emitter (E) of transistor Q210 are connected, current flows from the emitter of transistor Q210 to signal ground SGND. At this time, current flows through pins 1 and 2 of optocoupler ICZ210, causing the internal LED to light up. This structure utilizes the VCC voltage from the power chip to power the series resistor in the optocoupler, achieving low power consumption and improving the overall power consumption of the device.

[0014] The 5V DC power flows through resistor R215 to pin 4 of the optocoupler ICZ210. Because the internal transistor of the optocoupler ICZ210 receives light from its internal LED, the transistor conducts current to ground. One pin of resistor R216 is connected to both resistor R215 and pin 4 of the optocoupler ICZ210. High and low level signals flow through resistor R216 to the ZERO pin, and are then sent to the MCU for processing, thus reducing the voltage loss of the optocoupler series resistor due to the AC mains voltage.

[0015] This ultra-low power isolated zero-crossing detection circuit has a simple structure and ingenious design. By reducing the voltage supplied to the resistor, it minimizes the power loss of the optocoupler series resistor due to the mains voltage. Furthermore, it utilizes the VCC voltage on the power chip to supply power to the optocoupler series resistor, achieving low power consumption and improving the overall power consumption of the device. It also fully leverages the voltage from the switching power supply to power the optocoupler; because the voltage supplied by the power supply is lower than the mains voltage, the power loss to the optocoupler series resistor is low, meeting the product's low power consumption requirements.

[0016] The above description is only a preferred embodiment of the present utility model. However, the present utility model should not be limited to the content disclosed in the embodiments and drawings. Therefore, any equivalent or modified embodiments made without departing from the spirit disclosed in the present utility model shall fall within the protection scope of the present utility model.

Claims

1. An ultra-low power isolated zero-crossing detection circuit, characterized in that... include: The circuit consists of diode D210, resistors R215, R216, R217, R218, R219, R220, capacitor C206, transistor Q210, and optocoupler ICZ210. One end of diode D210 is connected to the AC power supply (ACL-AC), and the other end is connected to resistor R219. The other end of resistor R219 is connected to resistor R217, and the other end of resistor R217 is connected to the base (B) of transistor Q210. The emitter (E) of transistor Q210 is connected to signal ground (SGND). One end of resistor R220 is connected to the connection line between resistor R217 and the base (B) of transistor Q210, and the other end of resistor R220 is connected between the emitter (E) of transistor Q210 and signal ground (SGND). On the connection line, the collector (C) of transistor Q210 is connected to pin 2 of optocoupler ICZ210. Pin 1 of optocoupler ICZ210 is connected to one end of resistor R218. The other end of resistor R218 is connected to the power supply voltage VCC of the power chip. Pin 4 of optocoupler ICZ210 is connected to one end of resistors R215 and R216 respectively. The other end of resistor R215 is connected to +5V voltage. The other end of resistor R216 is connected to the ZERO pin of MCU. Pin 3 of optocoupler ICZ210 is grounded. One end of capacitor C206 is connected at the junction of resistors R215, R216 and pin 4 of optocoupler ICZ210. The other end of capacitor C206 is connected to pin 3 of optocoupler ICZ210 and then grounded together.

2. The ultra-low power isolated zero-crossing detection circuit as described in claim 1, characterized in that: It also includes capacitor C210, which is connected in parallel with resistor R220. One end of capacitor C210 is connected to the base (B) terminal of resistor R220 and transistor Q210, and the other end of capacitor C210 is connected to the emitter (E) terminal of resistor R220 and transistor Q210.

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